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ROYAL ARTILLERY METHODS IN WORLD WAR 2
A description of the field artillery tactics and gunnery used by the Royal Artillery and the artilleries of British Commonwealth armies. It includes some organisational details, review and commentary. It has a linked glossary.
Last updated 28 July 2002
This account briefly summarises the lessons of World War 1 and provides contextual information to help understand the British artillery. The artillery doctrine, procedures, main equipment and organisation used by the British were generally used by the artilleries in the Australian, Canadian, Indian, New Zealand and South African armies with only minor variations. This account uses the British terminology of the time; a linked glossary defines many of these terms. For brevity some details have been simplified.
The realities of each theatre, particularly the effects of terrain, meant that artillery technical and tactical procedures had to be adapted to suit them. Furthermore, they evolved throughout the war with experience, the characteristics of the theatre, enemy tactics and with technology. Of course evolution was not always a smooth process, particularly if the right equipment wasn't available!
CONTENTS
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BACKGROUND |
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ORGANISATION AND GROUPING |
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OPERATIONAL METHODS |
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ENGAGEMENT OF TARGETS |
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FIRE PLANNING |
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SOME ISSUES |
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REVIEW |
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This section provides background information as an introduction. It summarises the organisation of artillery, the artillery lessons of WW1 and outlines how mortars, anti-tank and anti-aircraft units were sometimes part of the field artillery. Detailed information about artillery organisation is here and a full listing of all regiments can be found here.
The Royal Regiment of Artillery (RA) in its modern form was created in 1924 by amalgamation of the Royal Field Artillery and the Royal Garrison Artillery. It is a regiment (a) of the British Army but includes two smaller regiments, the Royal Horse Artillery (RHA) and the Honourable Artillery Company (HAC). There were also colonial regiments. During WW2 the RA had five categories – field (including locating), anti-aircraft, anti-tank, coast and maritime. This account is concerned with the first, although the second, third and even the fourth undertook some field roles.
At the beginning of 1939 the regular and TA strength of the Royal Artillery totaled about 105,000. In mid 1943 the RA reached its peak strength, some 700,000 strong (about 26% of total British Army strength and about the same size as the Royal Navy), including about 5% officers, in some 630 regiments (b), 65 training regiments and six officer cadet training units. These included 130 regiments converted from TA infantry and yeomanry often retaining their previous regimental title as part of their artillery unit designation as well as badges and other accoutrements. However, the strength of the field branch (including anti-tank) in mid 1943 was about 232,000. The Regiment suffered some 31,000 killed during the course of the war.
Of the 630 or so regiments about 240 were field artillery. Their designation showed their equipment type:
Some other ‘odd’ designations were used from time to time, including assault field regiments in UK and Burma in 1943-44, such regiments had at least some self-propelled (SP) guns, on D-Day Normandy only tracked vehicles were allowed across the beaches in the first 8 hours. There were also ‘observation’/’bombardment’ units that provided observation parties and liaison officers for naval gunfire and to airborne formations. The ‘golf bag’ principle was adopted to some extent in most theatres. The Royal Marines fielded assault gun regiments (using 95-mm SP howitzers) during the invasion of Normandy but had no other field artillery and unlike their enemies the British did not use infantry guns. At the end of the war there were independent radar batteries and divisional Counter Mortar Batteries were forming. Some field batteries in Burma were equipped with mortars.
Regiments and batteries were uniquely numbered within their designation, although a few regiments that changed type did not change their number, particularly if they were regular regiments. Most RHA and HAC batteries were uniquely lettered, although a few regiments initially had lettered (A, B, C) batteries. Unique numbering was necessary because batteries were liable to be detached from their parent regiments, sometimes for many months. Since the battery numbering system did not always make the precedence of batteries clear, for operational and technical purposes batteries were known as P, Q, R and S within a regiment. This account follows British practice and uses ‘gun’ to mean both guns and howitzers.
Apart from the ‘war formed’ regiments and those that converted from infantry and armour, the battery is the unit of tradition in the RA.
The British artillery entered WW1 believing in the pre-eminent role of infantry whose moral qualities could overcome firepower. Artillery had a secondary role and paid lip service to indirect fire . They were not alone in this but very quickly changed their attitude. By early 1916 some senior artillery officers, notably Major Generals Herbert Uniacke and Noel Birch, had worked out how to use artillery effectively. The counter-bombardment battle had to be won, the barrage had to get the infantry onto their objectives and fire had to be available to defeat counter-attacks. By 1918 the 'all-arms' battle had become the recognised and practiced norm.
Significantly and often overlooked was the recognition that in attack the key role of artillery was to neutralise, not destroy, the enemy to enable the infantry to capture their objectives. By way of contrast as late as 1944 US doctrine stated 'In an attack of an organised position, the artillery must batter the enemy strength to the point of complete collapse before friendly infantry is committed to the assault.' (FM 6-20 Field Artillery Tactical Employment). The primacy of neutralisation in the all-arms battle is a key to understanding British artillery methods. This technique, using a moving barrage, had been introduced in the Boer War where it proved devastatingly effective when first used at the Tugela River in 1900.
For artillery at the Somme in July 1916 some corps got some bits right, some got none right and none got all right. The result was disaster. It took almost another two years to get all the elements together. This involved:
In mid 1916 both the Royal Field Artillery and the Royal Garrison Artillery re-organised so that all batteries had 6 guns (less for the latter's very heaviest). The remaining problem was the technology of mobile communications between observers and guns. This was not solved until the arrival of portable radios after the WW1, although radios were used for artillery communications in WW1. Nevertheless, by 1918 the British had created the most sophisticated and capable artillery system in the world.
After WW1, with the promise of no more major wars, artillery lapsed back to predominantly a battery focus, which was appropriate to imperial policing. However, while this may have been the day to day practice it was not the aspiration of the military leadership. They recognised the need to be able to fight a continental war against a 'first class' enemy. But they recognised that never again would they be allowed profligate use of men's lives and that they needed an army that was highly mobile with plenty of firepower. Their problem was lack of resources and low priority for the Army.
Only in Burma did RA operate mortars as main equipment, some African artillery regiments there had 3-inch mortars as did a battery in many field regiments. In North Africa. the Chemical Warfare Companies of the Royal Engineers operated 4.2-inch mortars from Alamein onwards, using conventional ammunition. However, from about mid-1943 the divisional machine gun battalions (one per infantry division) converted one MG company to 4.2-inch mortars (16 mortars in 4 platoons) and RE stopped using them. At the beginning of the war each infantry battalion had a mortar sections (2 × 3-inch), this was increased to 3 sections in most battalions from late 1940. Divisional reconnaissance regiments also had a 3-inch mortar platoon but motorised battalions in armoured formations did not. 4.2-inch mortars did not reach Burma until late in the war, although the Australians in the SW Pacific had them earlier. The degree of co-ordination between non-RA mortars and artillery varied, although infantry divisions had a 'support group commander' responsible for coordinating infantry 'heavy' weapons, a role viewed somewhat sceptically by RA officers.
Anti-tank guns were operated by artillery, infantry battalions and divisional reconnaissance regiments. Those provided by artillery were in divisional anti-tank regiments with additional regiments under control of higher formations and allocated as required. The other arms had one or more platoons per battalion. Initially anti-tank guns were limited to armour piercing ammunition. However, in early 1944 HE ammunition was authorised for direct fire tasks, the concern had been that too much HE would mean too much wear to the anti-tank guns and consequently lose accuracy for their anti-tank role. The scale was:
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6-pdr |
up to 25% |
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17-pr |
up to 5% |
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3-in M10 |
up to 30% |
In late 1944 anti-tank regiments in Burma became dual equipped, every anti-tank detachment had a 3-in mortar. Australian tank attack regiments received both mortars and 75-mm howitzers. Given the Japanese lack of tanks all this was a sensible use of resources. However, the same thing was sometimes done in Italy from early 1944 using 4.2-inch mortars, most notably by the Polish Corps at Monte Cassino and in other cases anti-tank batteries were effectively converted to 4.2-inch mortar batteries. In that theatre divisional commanders had 4.2-inch mortars available for issue as required.
From time to time RA anti-tank troop commanders inevitably acted as forward observers for field artillery units. Finally, 17-pdrs were given an indirect fire capability to enable them to continue attacking structures that became obscured during the direct fire engagement, they may have been occasionally used for more conventional indirect fire.
As the war progressed the air threat decreased and both heavy and light AA units were used in the field role. In Italy statistics reveal that many HAA regiments fired only a few thousand rounds at air targets but perhaps 50 times as many at ground targets! Most of this fire was indirect although HAA units were not officially issued with the necessary fire control equipment until late 1944.
LAA was usually used for direct fire, although there is at least one recorded incident of LAA being used for indirect fire controlled by an air OP. The were occasions, particularly in Italy, when LAA batteries temporarily operated mortars. More frequently from 1944, LAA fire was used to mark the edges of a barrage to help keep the infantry on the right course.
In 1938 the British field brigades were renamed regiments, lost their survey sections, and reorganised in two batteries each of 12 guns organised as three troops (except RHA batteries that had eight guns in two troops) and medium brigades became regiments of 2 batteries. The Commonwealth armies followed suit, in some cases not until early 1940. The field regiments changed again in 1940.
Table 1 – Regimental Organisations
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Regiment |
Pre 1938 |
1938 - 1940 |
After 1940 |
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Field |
4 × 6 guns |
2 × 3 × 4 guns |
3 × 2 × 4 guns |
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RHA |
4 × 6 guns |
2 × 2 × 4 guns |
3 × 2 × 4 guns |
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Medium |
4 × 6 guns |
2 × 2 × 4 guns |
2 × 2 × 4 guns |
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Heavy |
4 × 4 guns |
4 × 4 guns |
4 × 4 guns |
Troop commanders were included and each troop had a command post (CP) as did the battery. Troops were sequentially lettered within a regiment and divided into two sections (left and right) each of two guns. Guns being called ‘sub-sections’ and sequentially lettered within the battery. In consequence guns were always called ‘subs’. For more detail about organisations see 'Artillery Organisations'.
In earlier times the battery commander (BC – a major) had been the battery's observer, although he often brought forward a junior officer from the gun position. Troop commanders were captains and became their battery's main observers, although the third (in the three troop organisation) was severely limited by poor communications facilities. They operated as either Observation Post Officers (OPO) if the battle was static or Forward Observation Officers (FOO) if they were moving with the infantry. This highlights the distinguishing feature of the British artillery system, the more senior officers were forward. This reflected key lessons of 1917-18:
It had many important consequences, not the least of which was that they spoke authoritatively to the supported commanders and gave orders, not requests, to the guns.
The regiment's second-in-command was responsible for its gun area. Regimental HQ (RHQ) was there and operated by the adjutant. The senior officer on each battery position was the (battery) Captain (BK), who had particular responsibilities for administration. There was a command post officer (CPO) in the battery CP (BCP) and a gun position officer (GPO) at each troop CP (TCP) all with an officer assisting. The CPO was responsible for the overall gun position including its gunnery and local defence.
Medium regiments always had two medium batteries, each with eight guns. Heavy regiments had batteries of four guns. After Dunkirk they had four batteries with 7.2-inch howitzers as these became available. In 1942 155-mm M1 guns replaced 7.2-inch in two of these batteries and in late 1944 the 7.2-inch started converting to the longer range Mk 6 on the M1 carriage. Super heavy batteries had two guns, with three batteries in each mixed regiment. The various mountain and light batteries varied from four to eight howitzers, and mortar batteries generally had 16 tubes.
With the exception of the heavies, regiments usually had a single type of gun. However, in Burma after 1942 mixed equipment regiments were common and in other theatres some field regiments had both towed and SP batteries. In 1944 in Burma anti-tank regiments became dual equipped, each detachment had an anti-tank gun and a 3-inch mortar (12 per battery).
Most artillery was under command of the divisional artillery commanders, the CRA, a brigadier. All divisions and corps had their own HQRA, with both command and control roles. At divisional level this small HQ had 3 staff officers as well as the CRA. Above corps level HQs had an artillery staff branch, usually headed by a major general with advisory and command roles to and through the Commander and general staff.
Initially there was a second HQRA at corps under command of the CCMA who commanded the corps medium artillery and any GHQ field, medium and heavy regiments allocated to the corps. The basic scale for a corps artillery, not always achieved, being two army field regiments, two medium regiments and a survey regiment as corps troops. In France in 1940 GHQ had an additional 19 regiments, half of them medium. This gave the BEF (11 divisions in 3 corps) 60 regiments totaling 1280 guns. The British Liberation Army that returned to France in 1944 had 11 divisions (including 3 armoured plus many independent tank and armoured brigades) in 4 corps with over 65 regiments.
From September 1942 AGRAs were formed as 'army troops' with heavy, medium and field regiments, an ad hoc medium artillery group was used at El Alamein. The corps artillery was reduced to a medium regiment and a survey regiment although in practice the corps medium regiment rarely existed as such. From mid 1943 an AGRA nominally comprised one field regiment, one heavy regiment and one medium regiment per division supported. The AGRAs were under army, army group or theatre command and assigned to corps as required, normally one to each corps. However, for major operations a corps might get additional AGRAs, and sometimes they were allocated to a division and sometimes additional field and medium regiments were allocated to a division for an extended period. Initially AGRAs were without a signal company. As the war progressed their roles increased.
Some army field regiments became semi-permanently attached to independent armoured and tank brigades. There were quite a lot of these. For example at El Alamein there were 3 armoured divisions, each established with a single armoured brigade. However, there were actually 8 tank and armoured brigades present. These independent tank and armoured brigades were assigned to infantry divisions as necessary, although sometimes they reinforced armoured divisions. In either case they had to be provided with artillery. In late 1943 War Office Reserve and WO Pool regiments were created in each theatre from regiments not in divisions or AGRAs. Reserve regiments were for emergencies and could not be allocated without WO authority. Pool regiments were allocated as required by the theatre HQ but could revert to WO authority.
In late 1944 in NW Europe 21st Army Group (6 corps) had 7 British and 2 Canadian AGRAs. The largest AGRA was 1st Canadian in Italy that reached 10 regiments, but most were about 6 regiments, while the smallest was a super-heavy AGRA with 2 regiments. Although AGRAs were formed in India, there were never any in Burma and only one in the final months of the North African campaign (1st AGRA, in action with 19 French Corps in January 1943). Some army field regiments were converted to medium and heavy regiments, and HAA regiments were also assigned to AGRAs as the air threat decreased.
The divisional artillery comprised field regiments. Three regiments in infantry divisions and 2 (one self-propelled) in armoured divisions. However, forward infantry divisions in an advance were usually allocated a total of four field and two medium regiments, totaling 128 guns. The additional regiments usually came from AGRAs. In NW Europe heavy and HAA batteries were also routinely allocated to divisions for counter-mortar tasks.
It being a principle that artillery did not go into reserve, the firepower of the regiments of divisions in reserve was available to those in contact with the enemy. The British had three types of formal relationship between artillery and others, 'tactical missions' in modern terms, concerned primarily with control:
The last was typically given to the counter-bombardment (CB) staff in an HQRA for CB fire. Being ‘In Support’ did not prevent a battery being In Direct Support or At Priority Call. The consequence of these arrangements was highly flexible mobile firepower that could be provided where and when it was needed. When a regiment was allocated In Direct Support to a brigade it was sometimes placed 'Under Command for Movement' of that brigade, with all other aspects of command, including ammunition allocation, being retained by the HQRA.
In October 1940 field regiments were reorganised into three batteries each with eight guns (two troops) and their survey sections re-formed. This change did not happen instantly everywhere and the new organisation for a battery was not finalised until well into 1941, and continued to evolve throughout the war. The new organisation increased the number of vehicles and signallers. In 1943 establishments were standardised army wide so that similar numbers and ranks were allowed for similar tasks.
By the end of 1943 a towed field battery's war establishment strength was 198 including 10 officers and an SP battery's was 186, again with 10 officers. Medium batteries (5.5-in) were bigger, 252 (still 10 officers), because their gun detachments were large. Heavy batteries were only 166 with 6 officers. These large batteries enabled sustained 24 hour operations. It also proved a boon in Burma for local defence against ground attack.
An RA regiment comprised several elements from the establishment perspective. By 1943 these were the regiment itself, mostly RA cap badge, but with attached cooks (from the Army Catering Corps), a medical officer, and attached technicians from the Royal Electrical and Mechanical Engineers (REME). Then there was the signal section from Royal Signals, with its own officer and finally the Light Aid Detachment (LAD) from REME, about 13 strong with its own officer. The RA soldiers were divided into Tradesmen and Non-Tradesmen. The former included driver operators (signallers), driver mechanics, gun fitters, vehicle mechanics, equipment repairers, clerks, storemen and the 'Battery Surveyors' in the regimental survey section. By number the main non-tradesmen were gun numbers, drivers IC and signallers. The final element in the regiment were the 'First Reinforcements' who replaced RA battle casualties. They included officers, NCOs and gunners, including tradesmen, and in a field regiment totaled 54 including 5 officers.
The regimental headquarters was some 88 strong including 9 officers, this figure includes the regiment’s LAD and signal section as well as the 10 strong survey section with its officer.
The 8 gun field battery included four defence teams equipped with an AAMG and ATk rifle. However, initially only about 30% of the battery had personal weapons, although this changed to 100% in early 1943. The official scale was a pistol per officer, a machine carbine for Warrant Officers, drivers and motor cyclists, and members of LMG detachments. The rest carried rifles. In mid 1943 20-mm AA guns were approved for issue to all arms, with mountings capable of firing on the move and issued to towed artillery regiments and PIATs started replacing ATk rifles. The totals for a field regiment were 25 × LMGs, 13 × PIATs and 8 × 20-mm.
A 1941 25-pdr field battery had 12 motorcycles and 38 other vehicles of which five were for cable laying. In early 1943 disruptive painting patterns for vehicles became policy. By 1943 the number of motor-cycles had decreased to 7 and 4 jeeps ('5-cwt, car, 4 × 4' in British terminology) had appeared, to total 46 vehicles and motor-cycles.
In August 1941 the first Air OP (AOP) Sqn formed, these were RAF squadrons using light aircraft (Austers) with artillery officers as observer-pilots, eventually there was a squadron per corps (except in Burma), normally providing a flight of four aircraft to each forward division and AGRA. These squadrons first flew operationally in Tunisia. Each aircraft ('section') with its RA pilot and mixed RA/RAF ground crew could deploy independently. The engagement of targets found by other RAF aircraft, the Arty/R procedure, and a subject of extensive planning and preparation in the years before the war, continued. AOPs could engage targets on clear moonlight nights and developed an air photo capability and also directed naval gunfire. In the SW Pacific Australia did not create an AOP organisation and relied on artillery observers in 'army cooperation' aircraft of the RAAF. Canada, New Zealand and South Africa did not create AOPs either and their formations were supported by British squadrons.
Just as, if not, more significant in 1941, was a ‘bottom up’ tactical innovation that emerged in the surrounded town of Tobruk on the Libyan coast between Australian infantry and British artillery – close affiliation between a battalion and its direct support battery. This relationship spread rapidly throughout the British and like-minded armies. It was the critical element for a harmonious and trusting relationship between artillery and the supported arm, and the forward presence of the battery's senior officers was probably its key. With it came guaranteed fire support because the observers could order targets to their battery. However, it did raise a problem in that the supported arm tended to view the battery as ‘theirs’, often failing to recognise that artillery fought at both the tactical and operational level and the implications of ‘In Support’ and mobile firepower.
The main problem was four companies in a battalion but only two observers in a battery, so the latter often had to move between companies in battle. This could be a problem, particularly in Burma, where it was found that a battery had to deploy up to five observer parties. This was usually achieved by rotating gun-end officers and soldiers through the additional observation parties.
Close affiliations developed between brigades and their direct support regiments. The regimental commander (CO) increasingly accompanied the supported brigade commander wherever he went and by late 1943 this became official artillery policy, with the CO establishing a small HQ at brigade HQ. In regiments without a direct support role (or under command of a brigade) the CO was based at regimental main HQ in the area of his battery gun positions. Direct support BCs mirrored this with the battalions and regiments they supported.
As the war wore on the field role of anti-aircraft and anti-tank batteries increased because their specific targets decreased. The former often provided a significant component of major fire plans and HAA batteries (3.7-inch guns) were increasingly used against opportunity targets. The main reason that HAA were not used more extensively in the field role was that they were not officially authorised to have the necessary technical fire control equipment until the end of 1944.
The gunnery staff was responsible for instruction at artillery schools in UK and overseas theatres, which greatly facilitated in-theatre regiment's re-equipment. They also wrote most of the wide variety of artillery training publications having designed and developed the drills and procedures and many of the instruments. However, their most visible role was at practice camps, where they critiqued the gunnery and its compliance with official procedures and reported on the unit’s performance. The result of this quality control system, after late-1941 or so on completion of expansion and re-organisation, was a high standard of uniform gunnery throughout the RA and a body of men with a deep understanding of it.
The British Army generally avoided standard battle drills until about the middle of the war. However, the need for centrally controlled firepower emerged from the 1920s onwards so artillery drills emerged quite early, although observation of fire procedures and gun drills dated back to well before WW1. British artillery processes placed great emphasis on drills, both on the guns and in command posts (CP). This use of drills had several benefits:
Almost all artillery drills involved two or more soldiers, this was part of the goal of having everything double-checked to prevent errors. A characteristic of the British artillery system was great tactical flexibility by having units’ senior officers forward, underpinned by well honed standard drills and uniform procedures for gunnery that enabled junior officers to run gun positions.
Unless a battery was operating independently, the CO selected the gun area in consultation with the supported brigade staff and HQRA. BCs were given a zone for their battery, which reflected the needs of the battalion they were supporting, if this was forward. The BC selected a central point in this, which enabled him to designate the battery zero line, although until 1941 a regimental zero line was normal. This was the rough bearing from the battery to the zone centre. Terrain permitting, the batteries of a regiment normally deployed within 1,000 – 2,000 yards of each other. The main reason for this closeness was speed of survey, ease of communications and ammunition supply, and typical brigade frontages.
During deployment the regiment and batteries operated as several tactical groups that provided reconnaissance (G Party) and preparation (bty HQ party) of the next positions in readiness for the main bodies comprising the gun and ammunition groups, and B echelon. These parties can be seen in the unit details linked to 'Artillery Organisations'.
Figure 1- Schematic Regimental Layout Showing Telephone Lines
See Figure 2, within batteries the troops normally deployed a few hundred yards apart, with the right hand gun the pivot gun. This meant that a field regiment presented six separate gun positions as targets for CB fire. The guns in a troop normally deployed about 20 yards apart, initially in a straight line but a more irregular pattern after 1941. However, this varied with circumstances, notably the terrain and threat from air attack or CB fire and if the terrain was difficult the layout could be in any shape to accommodate the guns.
In Burma the terrain often meant that gun positions were extremely tight, perhaps 500 × 200 yards for a regiment and these tight perimeters aided local defence in a theatre where ground attacks on gun positions were normal. Gun positions in Burma often resembled the 'Fire Support Bases' used a generation later in another South East Asian theatre, and in early 1945 a bulldozer was added to each battery. Local defence arrangements became well developed, at night camouflage nets were removed from gun pits and only one man remained in a gun pit unless 'take post' had been ordered, gun pits were the primary target of Japanese grenades. The usual practice at night was that only LMGs fired and then on fixed lines along wire entanglements, the close battle was fought with grenades and bayonets. The only VC awarded to an artillery NCO in WW2 was to Havildar Umrao Singh of 33rd Indian Mountain Battery when defending his gun.
Each TCP was connected by line to their troop commander (observer), to each other and to the BCP, which in turn connected to the BC, the other batteries’ CPs and regimental HQ. Sometimes these links were further duplicated to give redundancy, and at the beginning of the war visual signaling was still used occasionally. Radios connected the main elements of the battery, and RHQ, from the beginning of the war. It became increasingly important as radios and operating skills improved, and line was used less. It became a matter of pride that artillery communications were always available and when supported arm communications failed they relied on artillery communications. For more detail see 'Artillery Communications'.
Observation posts (OPs) were usually selected by the BC to provide observation throughout the battery’s zone. However, this selection usually had to be balanced by being in or close to a forward company area. The OPOs then silently registered their zones of observation by visualising the zero line and possible target areas in relation to it. Sometimes the zone would be registered by firing. Time permitting, observers would produce a panorama drawing of their zone highlighting reference points, the key features and data for them, and any registered targets.
Figure 2 – Schematic Battery Layout with Line
The GPOs, normally directed by the CPO (who was the battery deployment officer and selected the troop positions) selected individual gun 'platforms'. The CPO was directed by the regimental second-in-command and received the zero line from his BC. They had to cover the ordered zone (which meant avoiding close or high crests). An ideal position would have a low crest about 500 yards in front of it, this clear field of fire was in case they came under tank attack and the crest provided some cover from flash spotting. The TCP was positioned to the upwind flank. The BCP and battery director were positioned somewhere between the troops. All vehicles were sent to the wagon lines some hundreds of yards away from the guns and there were strict track plans as part of the battery’s concealment measures. In action the guns of each troop were numbered from the right, the pivot gun usually being Number 1. Each gun usually ended up with a different number on each position, the sub-section letters were not used for gunnery.
A battery did not deploy onto a new gun position as a whole, the CPO and GPOs went ahead to prepare the position. From the time the guns left a RV about one mile from the new position they were expected to be ready to fire in 15 minutes, more at night. Of course this would usually be only the lowest state of survey and minimal line laying. Sometimes the two troops would move separately so that one was always in action (‘step-up’). Roving troops or sections and ‘pistol guns’ were sometimes used for registration tasks, deception, ‘sniping’ and destruction shoots.
On coming into action a troop was oriented in the zero line by their GPO using the troop director, either by individual bearings from the director or through a distant aiming point and corrections for relative position. These troop directors were oriented from the battery director.
‘Quick actions’, where guns came into action on an unprepared position in response to a call for fire during a move were used. The time from a call to being ready was about 8 minutes. This technique was quite widely used in the desert. As the war progressed, it became more normal for another regiment (not moving) to join the moving regiment’s radio net and so be able to quickly respond to calls for fire.
British doctrine was to select and prepare an alternative position for every gun position occupied. This position would be several hundred yards from the primary position. The minimum level of preparation was to select gun platforms, fix the pivot gun positions and plot them on the artillery boards at the main position, and reconnoitre the route between main and alternate positions. A GPO could request permission to move his troop to the alternative position from the battery's CPO, who was normally required to obtain the permission of the Adjutant at RHQ.
Of course in theatres such as SEAC the terrain sometimes did not provide space for alternative positions. Furthermore it likely that in the later stages of the war, where the enemy CB threat was negligible, batteries did not bother about preparing alternative positions.
Imperial and expeditionary operations and invariably external lines of communication had given the British Army a keen appreciation of logistic issues. Artillery ammunition is a major logistic load in any army. The basic method was to use rail transport as far forward as possible (not far into Burma!) and then trucks from the railhead. The British Army dealt in First Line and Second Line ammunition holdings. First Line were held in and moved by the unit. Second Line was held on wheels by Army Service Corps (ASC) ammunition companies (later multi-function transport companies) organised in divisional columns. The Second Line ammunition scale was basically a transport platoon's worth per regiment. Each AGRA also had their own ASC company. However, for major fire plans ASC vehicles would dump ammunition to the gun position. The definition of dumped ammunition was that it was more than could be carried in artillery units’ vehicles.
In 1940 a field battery’s total First Line ammunition load was 1080 rounds. It was subsequently increased to 1376 for both towed and SP batteries giving each gun 114 HE, 16 smoke and 12 armour piercing, this evolved as further varieties became available. Each 25-pdr section (two guns) had three gun tractors and four ammunition trailers (often called ‘limbers’) carrying a total of 224 rounds, and at least one trailer deployed with each gun, at least until gun pits had been dug and the ammunition in the tractor was off-loaded. 25-pr SP batteries carried 102 rounds on each gun and a further 64 in a section half-track.
After 1940 medium batteries carried 800 rounds at first line, 40 rounds on each gun tractor and the remainder in the battery ammunition vehicles. Heavy batteries (7.2-inch) carried 56 rounds per gun or 80 rounds per 155-mm. These were carried on the gun tractors, 2nd gun tractors and a 3-ton truck per gun. British doctrine was to remove all vehicles from the gun position so only ammunition trailers remained close to the guns.
Medium and heavy shells were delivered ‘plugged’, fuzes were provided separately and had to be fitted before shells could be fired. Field shells were delivered boxed and fuzed, instantaneous fuzes in the case of HE. All HE shells were painted a sand colour. If HE airbursts were require the instantaneous fuzes were removed and time ones fitted. 25-pdr shells were delivered in steel boxes of 4 shells and cartridges in steel boxes of 8, each cartridge in a sealed can. Ammunition trailers carried ammunition that had been unpacked, which meant that ready-to-use ammunition was immediately available and didn’t have to be re-packed when guns moved.
There were no ammunition vehicles at regimental level. However, regimental commanders could centralise some of their batteries’ ammunition vehicles to provide a centralised mobile reserve.
Re-supply was usually by collection by battery vehicles from an Ammunition Point (AP) - the Second Line stocks, usually within very few miles of the gun areas. APs were operated by the ASC ammunition or transport companies, which in turn usually collected ammunition from ASC third line transport companies delivering from railhead to an Ammunition Refilling Point.
Each battery had its own fitters and mechanics and these together with the Battery Quartermaster Sergeant and his storemen and cooks, the ammunition group and the battery office operated in the battery wagon lines. Food for the battery area was usually prepared and distributed under battery arrangements. The Battery Sergeant Major was responsible for the wagon lines, although before the 1940 re-organisation there was a wagon lines officer.
At regimental level there was the regiment’s B Echelon under the command of the Quartermaster. Unit B Echelons were often grouped together under brigade or divisional arrangements.
Each troop commander (and BC) had an OP assistant, usually a bombardier. By 1942 each party had three radios, one fully integrated in their vehicle, one for FOO manpack and one on the supported infantry or armour net. The last improved situational awareness and enabled the supported arm to indicate targets to a FOO/OPO. If the observer was unable to see the target then the supported arm directed fire via the observer using simplified procedures (giving either corrections or observations). A third observer party could be deployed from resources at the gun position if the battery was up strength. If a troop commander was required to act as an FOO or liaise with the supported arm then the OP assistant would takeover, inevitably this also happened when observers became casualties. In Burma additional observer parties were created often led by warrant officers or sergeants from the battery and it was general practice to rotate officers and soldiers through the battery's OPs when conditions were static. In some cases in Burma OP deployment was planned regimentally to ensure optimum coverage in difficult terrain.
The observation officer's duties were:
In most types of regiment BCs and troop commanders had an armoured tracked vehicle, the Universal Carrier (Lloyd or Windsor carrier). COs in field regiments were equipped with Universal Carriers from mid 1943. Nevertheless, other types of vehicle were adopted including light tanks, armoured cars and M14 half-tracks ('15-cwt, truck, half-track' in British terms). In early 1944 the official position was as follows:
Tanks had started replacing the armd OPs in the field regiments in armoured divisions from 1942. The basic policy was that OP tanks should be the same type as used by the supported tank unit and in some cases, such as armoured regiments with "I" tanks, the armoured unit held tanks for FOOs . However, the policy could not always be followed and in some cases Ram tanks were used (a Canadian design used as the carriage for Sexton SPs but not as a tank in armoured units). Radios were standardised as 2 × No 19 sets and 1 × No 38 set per OP tank and stowage modified for some artillery equipment. In some cases (eg Covenanter, Crusader and Ram) a dummy gun was fitted to provide space for the radios. In March 1944 the scale of OP tanks was as follows:
This reorganisation also meant the withdrawal of OP tanks from regiments in infantry divisions (where batteries held one each), AGRAs and tank 'battalions'. The tanks held by brigade HQs were a pool for use by regiments in direct support of these formations. They had RAC crews who were joined by an OP officer and his OPA, unlike the tanks held by RA regiments that were fully crewed by RA (usually the OP officer, his OP assistant, a driver operator and a driver mechanic). Armoured division HQs also held a tank for their CRA. The tanks for GPOs also provided immediate replacements for OPs.
The observers’ basic equipment were binoculars, map, compass and protractor. Batteries also held telescopes, tripod mounted binoculars, optical range finders, directors and artillery boards for their OPs. However, such equipment was not always conducive to a well concealed OP and certainly inappropriate for an FOO. Manpack OPs became important in some theatres, this was achieved by reinforcing the normal 4 man OP party with 6 porters to help carry the 2 radios and associated equipment.
Signallers and GPO/CPO assistants staffed the CPs in the various types of battery. There were 8 CPO/GPO assistants in a battery. They were non-tradesman specialists trained in CP procedures, some were NCOs up to lance sergeant. For most of the war they had 15-cwt trucks but SP batteries had half-tracks for their battery and troop staff (apart from the GPOs with their OP tanks) and some batteries used a fitted for wireless version of the 'Quad' gun tractor. Towards the end of the war GPOs in SP batteries replaced their tanks with different armoured vehicles, these were the Canadian Ram carriages (used for Sexton 25-pdr SP and as APCs where they were called Kangaroos).
All CPs had similar fire control equipment. Most important was the artillery board and its associated instruments. This board was 30 inches square (there was also a 21-inch version) with linen reinforced paper pinned to it. This was gridded, normally the scale was 1:25,000 and the grid could be either yards or metres depending on the type of map used in the theatre. A cylindrical brass pivot was positioned at the correct location to represent the ‘pivot’ gun of each troop to about 10 yards accuracy. A steel bearing arc aligned to the zero line was pinned to the board and a range arm rotated on the pivot along the bearing arc.
Each gun was commanded by its “Number 1”, a sergeant, this designation being from the formal gun drill that gave a number to each role in a gun detachment. 25-pdr detachments were 6 strong, those for medium guns 11, and 13 for heavy guns. For a 25-pdr No 2 operated the breach, No 3 lay, No 4 loaded and Nos 5 & 6 handled ammunition. Reduced detachment drills enabled a 25-pr to be fired with 4 men. Detachment members were cross-trained in the different roles. One of them, usually a bombardier, was ‘coverer’ the No 1’s deputy and another was usually appointed ‘limber gunner’ and responsible for carrying out routine maintenance.
Apart from some US origin guns that used panoramic telescopes in mils, dial sights were graduated from 0 to 359 degrees and could be set to the nearest 5 minutes. They usually recorded the zero line by reference to a distant object, (or closer night picket) called the aiming point. Aiming posts or a parallelescope were also used, the latter being best when guns were well dug-in. All these devices ensured parallelism between guns was maintained when the position of guns’ dial sights changed as the guns moved when firing or aiming at targets widely apart. SP guns were fitted with binnacle compasses to ensure the vehicle oriented itself correctly when coming into action.
British guns usually used one man laying, by which one man layed in both line (using the dial sight) and elevation using the gun rule and sight clinometer. This was faster than two men laying used in most other armies, and the gun rule made the total process even faster. The gun rule enabled a command post to order ranges in yards, not angular elevations, to the guns. It meant that the CP didn’t have to calculate them for each gun (each gun had different MV), which saved time. The sight clinometer was for angle of sight. Guns, and mortars in RA use, were always re-layed between every round fired. Guns also had field clinometers when more accurate laying was required, such as the destruction of point targets, and the elevation calculated in the CP.
The detachment used a fuze indicator for air-burst fuzes. This enabled them to find their own fuze length when given the range. However, it also accepted a 'corrector' setting that the CP calculated to compensate for non-standard conditions for non-mechanical time fuzes. Observers adjusted the height of burst by ordering correction to the corrector not the fuze lengthen. Nevertheless some guns, notably those lingering from WW1 or of US origin, did not have gun rules or fuze indicators. However, by early 1944 there was a program to replace all US panoramic telescopes with dial sights and to produce gun rules and fuze indicators for all guns.
Normally one gun in each troop had a thermometer used continuously to measure charge temperature. Every gun had a Memoranda of Examination that accompanied the gun wherever it went. Most importantly it recorded the daily number of rounds fired in terms of their equivalent full charges (EFC), this and recorded wear measurements enabled the MV to be updated without calibration firing.
In January 1942 a training instruction was issued that detailed the technical knowledge required by a GPO, some are explained in this account. They were:
The artillery board was the usual means of calculating map data, unless accuracy took precedence over speed. The battery CP had a board set up for each troop, and for some types of engagement the procedures involved comparing the data produced in BCP and TCPs as a check against errors. Generally the two types of CP had different responsibilities. The two troops could, of course, engage different targets simultaneously.
When available, there was a tannoy loudspeaker at each section connected to their TCP by line, each gun had a handset connected to it. Pressing the handset's pressel switch caused a light to switch-on on a display box in the CP to show that the gun had received its orders. Alternatively orders and reports could be shouted with or without the help of a loud hailer and acknowledged by visual signal. This meant that orders were given to the guns quickly and correctly, thus saving time. However, SP guns were fitted with radios.
For a detailed description of the gunnery problem see 'The Basics of Gunnery'.
Survey is concerned with providing fixation (ie exact location) and orientation (where grid North is) to the guns and other equipment and places. The goal of survey is to provide this data accurate to the map grid in use. As an intermediate step surveyed points could be put on a common grid, so that batteries are correct in relation to one another but not to the map. The mechanics of survey involve measuring bearings and distances (‘traverses’) from survey control points and related trigonometric calculations. However, regimental surveyors calculating from sun or star observations could provide accurate orientation earlier than accurate fixation.
Accurate survey was essential for predicted fire and a common grid facilitated multi-battery engagements. Procedures for the latter had been developed soon after WW1 as a fast process suitable for mobile operations instead of relying on RE survey units to survey all battery positions.
Survey practices evolved throughout the war. However, it was always a ‘bottom-up’ process, unless deployment planning enabled survey to take place in advance. Each battery started by establishing its own fix and orientation. The regimental survey section then brought all batteries onto a common grid by establishing bearing pickets in the battery areas. Subsequently surveyors from the corps survey regiment brought all regiments onto an accurate grid and orientation (theatre grid). In some poorly mapped theatres division and corps grids were also used as intermediate stages. Mapping, and survey above the level of the corps survey regiment, was the responsibility of the Royal Engineers. The corps surveyors used theodolites and had mechanical calculating machines; regimental ones used directors and calculated using logarithms.
At each change of grid the batteries corrected their own fix and orientation, and modified their registered target data. In the desert from early 1942 air-burst fixation was used. A designated troop fire a series of high air-burst shells, other batteries observed these with a director, enabling them to all put themselves onto a common grid.
Meteor telegrams provided data to graphically calculate corrections of the moment, essential for predicted fire. The provision of meteorological data was a RAF responsibility, although in Canadian and Australian formations artillery meteor units did it. However, conversion of the meteorological data into meteor telegrams for issue to artillery units was often done by corps survey regiments and these regiments had a small RAF met detachment in each sound ranging troop.
Early in the war meteor telegrams were issued as at 0600, 1200 and 1800. By about 1942 they were issued every 4 hours, although for major operations 2 hourly messages were sometimes used. In 1942 RAF mobile meteor stations were provided to each corps, and in 1943 sections were established in each HQRA and HQ AGRA. These sections could fly balloons and receive upper air temperature broadcasts enabling them or survey regiments to prepare meteor telegrams. However, each was very small (an officer and 2 NCOs) and could not individually produce meteor telegrams continuously every few hours.
Meteor telegrams provided, for different heights, wind speed and direction and air temperature and pressure. These were calculated by tracking local met balloon ascents and receiving high altitude wind broadcasts. Towards the end of the war balloon tracking was often done by radar.
An alternative to using meteor telegrams to produce correction of the moment data was to use data derived from accurately ranging a datum point. A related but simpler technique was the witness point, which enabled firing data for one target to be adjusted by ranging another.
MV data is essential for predicted fire and to ensure that the guns’ fall-of-shot is not too spread out in range relative to one another. As guns’ barrels and chambers wear from firing their MV decreases and shells become less stable in flight. However, MV also varies with differences between different manufacturing 'lots' of propellant and between types of propellant in worn guns. Calibration is the process of determining a gun's MV by firing.
Maintaining up-to-date MV data in war was a major challenge. Again practices evolved throughout the war because while the best solution is to remove the guns to a calibration range this was seldom practical. For example, in the period before El Alamein medium guns were being calibrated every three days.
British practice evolved to comparative calibration in which a corps calibration troop was kept accurately calibrated and moved from unit to unit to shoot alongside their guns and compare the ranges achieved for different charges fired at the same elevation. The differences enabled calculation of revised MVs, these were maintained reasonably up to date by measuring guns’ wear and recording the EFCs fired and making corresponding adjustments to MV. However, this did not solve the problem of variations between batches of propellant, although sorting into batches and having all guns use the same batch for a target ensured consistent firing. Nevertheless in Italy in 1944-5 even this proved impossible because there were so many different batches from ammunition factories in many countries. This adversely affected the accuracy of predicted fire.
British doctrine for the use of artillery in the all-arms battle was, in summary, as follows:
In attack:
In defence:
The British considered the shell to be the weapon of artillery, not the gun. HE shells were filled with TNT or TNT/Amatol, but in early 1945 TNT/RDX was introduced for improved anti-personnel effects.
The RA entered WW2 with HE and base ejection (BE) smoke for field batteries. An early decision was made not to introduce a mechanical time fuze for HE because of the training difficulties for a citizen army. Fortunately, at Canadian insistence, this decision was changed although fuzes did not appear in quantity until late 1942. Ricochet fire was also used as a means of obtaining air-bursts, it was far less effective than time fuzes.
On 18 December 1944 SHAEF released VT fuzes for field artillery use. However, due to their unreliability, such as early bursts in heavy weather, the British did not generally use them against opportunity targets.
WP smoke was not adopted, apart from with 105-mm. It was considered less effective than BE smoke for screening purposes and trials showed that its anti-personnel effects were very limited against troops in temperate climate uniforms. Gas shells were developed but, of course, never used.
Propaganda shells (filled with leaflets) were adopted and used from early 1943 onwards. Illuminating (star) shells were also introduced for both battlefield illumination and for night target marking to aircraft. Coloured smoke (red, blue, yellow and green) was introduced in 1943 for the same purpose during daylight. Incendiary and chaff (electronic counter-measure) shells were also developed but do not seem to have been widely used.
Several sets of trials were undertaken to establish the effectiveness of HE fire for wire cutting and destroying mine fields. Although weight of fire data was produced it was not satisfactory solution for either problem and was not generally used.
A characteristic of 20th Century warfare was the ‘empty battlefield’. Forward troops and OPs are not presented with a continuous array of targets to attack, the enemy remained concealed. They only appear when attacking or because of a local misjudgment. For the FOO, targets may ‘announce’ themselves, often unpleasantly. However, finding their size and layout can be a challenge. Behind the forward area matters become easier, although the enemy quickly learns what can be seen from where and behaves accordingly.
As in WW1 air observation was a key means of observed fire against hostile batteries (HB) and other targets beyond the view of ground observers. AOPs, particularly in Burma, played the vital role once they became available, and were later able to take useful photographs as well. Air photo reconnaissance was also a major asset and other RAF aircraft could report and engage ground targets using the Arty/R procedure. Airborne formations had their Forward Observer Unit (FOU (Airborne)) that provided communications to other artillery in range and provided additional observers to supplement the single air landing artillery regiment in the division.
The corps survey regiment was the source of more technical target acquisition resources particularly for CB purposes and provided sound ranging and flash spotting capabilities. Locating HBs and mortars was not enough, as WW1 had shown a CB organisation was required and each corps had a Counter Battery Officer and staff. Late in 1944 divisional counter-mortar batteries were authorised as well as other specialised batteries. More details about this target acquisition are in 'Target Acquisiton and Counter Bombardment'.
Air-burst ranging was first recognised in 1941. It could be used for three purposes, to range targets of known co-ordinates but out of sight on the ground, as a datum point procedure to produce corrections for non-standard conditions, and for calibration of guns in their battle positions. The corps survey regiment had a troop for this purpose.
Observers could order targets to their own battery, they did not have to request it from the BC or RHQ. There were four methods of giving a target's location:
The second tended to be the preferred method when ranging because it was the quickest, the British view was that speed was more important than ammunition economy. More importantly being ranged might disrupt the enemy's activity and prompt fire gave moral support to friendly forces before the target was properly ranged and gunfire applied.
The observer also decided if corrections for non-standard conditions were to be applied. If ranging they usually weren't unless accuracy was important for the safety of own troops or the meteor correction was large (at around maximum range in summer in the desert the guns might fire some 700 yards too far). The result was that the observer warned the battery of the impending target while measuring range, switch and angle of sight (zero was generally used if speed was important). He ordered this to the TCP and having alerted the guns the GPO selected a charge and ordered the observer's data to the guns, which set it onto their sights (the gun rules meant that the CP did not convert the range to an angular elevation). Ranging was normally by a section, the 2 guns using either the same or different range. This procedure meant that it generally took about 30 – 60 seconds from receiving the observer's data to firing the first ranging shells. Observers were supposed to be able to produce their data in about a minute from identifying the target.
Ranging corrections were ordered relative to a line through battery and target (BT). If the observer was close to this line then he ordered a correction to bring the shells onto BT and bracketed the target for range. This procedure demanded that he establish a long bracket (successive shells over and short of the target) usually of 400 or 800 yards. The bracket lengthen was halved until achieving a short bracket of 100 yards (or target round or contradiction - section’s shells either side of target), then he split the 100 yard bracket and ordered the appropriate fire for effect, usually gunfire. If the observer was at closer to a right angle to the BT line then he would first bracket for line. The observer could use distances in yards for line corrections if required. Corrections were always sent as orders to the guns to move their aim-point, they were never observations of where the shells fell relative to the target.
When ranging was complete and Gunfire ordered then the link procedure (using rapporteur or window methods) was carried out between the two TCPs. The controlling CP converted their range and switch to that for use by the link CP and sent it to them, and the link CP ordered it to their guns.
The British recognised five different categories of target outside fire plans, with a sixth added in 1943. These were:
Predicted fire could be employed against any suitable target and 8 figure (ie 10 yard or metre precision) map references or coordinates were usually used. Predicted firing data was calculated by both BCP and TCPs and checked against each other. Normally map data was taken from the artillery board for predicted fire.
Trigonometric calculations using 4 figure logarithms were used with registered targets to find the actual map co-ordinates of the target after taking out corrections for non-standard conditions. This was called reduction. They were also used with datum shoots to calculate bearing and distance and hence the correction for non-standard conditions by firing.
Another alternative for ranging was ladder gunfire whereby each gun in a troop fired one round at a different range and a short interval, usually enabling the observer to make a single correction and order gunfire, although the observer need good observation of the target area for this.
For large targets the fire of troops, or batteries in multi-battery engagements, could be moved individually so that the full target area was covered, although in multi-battery engagements this was quite large in any case. The alternative was sweep and/or search by which the guns varied their aim-point in line and/or range every round or few rounds. The observer (or fire planner) ordered the size and pattern of these variations.
However, a key feature of the British system was that for opportunity targets the observer decided the type of ammunition to be used and the number of shells to be fired, with the exception of multi-battery targets when the observer was not 'authorised'. In this case he was given an ammunition allotment. The manner in which fire was applied was also left to the observer and his experience, although useful techniques were disseminated. For example in Normandy it was found that in the right conditions smoke could force German infantry out of their fighting positions in the bocage.
Recorded targets were registered or predicted. Procedures, including target numbering, evolved significantly during the course of the war. The problem was to ensure that the same number was not used for different targets within the same control domain, numbers being allotted by observers, commanders, staffs or CPs. Generally each had blocks of numbers unique to them in a domain. Numbers were prefixed by a letter or two that showed the domain. 'P' was used for battery level, 'M' for regiment and 'U' for division. A target 'M2' would be recorded in all batteries within a regiment, and different regiments would have the same number for different targets. If it became a divisional target it would become 'U' with a new number allotted by HQRA, it would then be circulated to all batteries in the division.
Until 1942 multi-battery procedures for opportunity targets were not particularly slick, although there was a choice of several methods developed from the mid-1920s onwards. Nevertheless, in May 1940 a British regiment destroyed a refueling panzer battalion in what is generally recognised as the first successful use in war of a radio controlled multi-battery attack on an opportunity target. However, in 1941 Brig HJ Parham, the CRA of 38 Division, invented and tested new procedures. These culminated in demonstrating a 144 gun concentration against an opportunity target within 5 minutes of the target being called. In mid-1942 XIII Corps conducted further trials and new doctrine was issued late that year. These concentrations were known as Mike (regiment), Uncle (division), Victor (corps), William (army) and Yoke (AGRA) targets and always initiated by the radio call “Mike Target, Mike Target, Mike Target” (or Uncle, etc) that galvanised CPs and guns to action.
Any observer could request such engagements, however, some observers including AOP, were authorised to order them. It was usually Standing Orders that a BC had this authority for his regiment, troop commanders were given it as required. BCs of medium batteries were often CRA’s or CCRA’s Representatives and authorised to order the divisional or corps artillery and have communications on the divisional or corps artillery radio net. This authority was sometimes given to field BCs and observers, and there were sometimes CAGRA Representatives with similar authority.
Authorised OPO/FOO were on their regimental radio net and sent their target to the adjutant at RHQ and batteries in the regiment, unauthorised observers sent the target to their BCP for passage to the adjutant and other batteries. If the target was Uncle or higher the adjutant forwarded it to HQRA and the other regiments in the division who forwarded it to their batteries. If there was an assigned AGRA then HQRA sent it to them for their regiments and their batteries. The process was repeated, but more widely, for Victor targets. The first battery reporting ‘ready’ usually did the ranging, starting immediately. If the observer was’t authorised it was usually their own battery because they got the target details first. In essence multi-battery targets relied on good procedures for fire control and communications. The system was speeded up further in armoured divisions in NW Europe by deploying HQRA to the leading brigade HQ during an advance.
Targets were located using a map reference or target number. The basic process for ranging was to use a single gun, ordering corrections to it that all batteries in the engagement applied, unless otherwise ordered. If the correction was less than about 500 yards, it was ordered in the form Left or Right and Add or Drop in yards, which was applied by each battery to its own BT line. If more than about 500 yards then a cardinal point bearing and distance was used. Since these large concentrations covered quite large areas (regiment – about 250 × 250 yards, division about 350 × 350 yards, division with AGRA about 400 × 400 yards) precise corrections were generally deemed unnecessary.
In each battery all CPs calculated map data, which had to agree to within 50 yards and 30 minutes between the BCP and TCPs. On completion of ranging a regimental target it was usual to fire a single round from a pivot gun in each battery, and from each regiment for multi-regiment targets, before ordering gunfire.
Obviously the more regiments firing at a target the bigger the area affected by the fire. However, this was not a linear relationship. Basically, each troop’s mean point of impact (MPI) would be a distance from the MPI of the whole concentration in some direction. The more troops there were the greater the probability of there being some at a greater distance, a normal probability distribution. This is explained in more detail in Errors and Mistakes.
Linear regiment or bigger concentrations, oriented as required for the target, also became common around the time of El Alamein in late 1942, they were popularly called ‘stonks’. In 1944 stonks were formalised and standardised as 525 yards long, this lengthen being suitable for all types of regiment and its calculation was speeded by use of templates in the CPs. However, 2 NZ Division continued to use its 1200 × 300 yard stonks. Some divisions introduced SOPs for pattern fire, several parallel stonks, with the field regiments firing those nearest to own troops, or other standard distributions not based on stonks. In Italy predicted concentrations with all guns firing together were called 'murder', and some divisions fired them with all guns directed at a common aimpoint instead of parallel.
Timings are not entirely clear. In the early days a Victor target by 1st Canadian Corps in Italy using 668 guns (30 Canadian, British and Polish regiments) was timed at 33 minutes to time on target (which was a slow method). By the end of the war Victor targets with 1000 guns were not unusual, the British was the only army routinely using such large concentrations against opportunity targets. From early 1944 Mike, Uncle and Victor targets were used increasingly in Burma. An army (William) target was the largest but because there was no HQRA at Army level it was controlled by one corps HQRA requesting additional fire from another that was 'In Support'.
There were two aspects to the time to engage a formation target. That taken to range and that taken to allot the batteries and pass orders, reports and any corrections through the hierarchical communications system, and this would depend on the number of links there were in the chain and the number of stations on each link. A Mike target by an authorised observer probably took just ranging time, starting almost as quickly as a battery target, and in NW Europe where the maps were quite good and meteor corrections not huge there were probably seldom more than four ranging rounds, perhaps 90 seconds between each. Unauthorised observers had first to get an allotment of batteries or regiments, which increased the time.
While the direct support units were responsive to the supported arm, there were also AOPs and observers from medium and heavy batteries under corps or AGRA control. In Italy co-ordination procedures had to be introduced through use of a ‘shell line’. Basically the divisional artillery initiated targets within the shell line in their boundaries but the others could only initiate beyond it unless co-ordinated with the division. If an advance was underway then the shell line was usually set at the day’s objective.
FOOs would select DF targets for defensive fire in consultation with the supported company commander and submit them to their BC for co-ordination. From these, in discussion with the battalion CO, the BC would designate a DF(SOS) target for the battery, which the guns aimed at when not otherwise engaged. The battery's DF list would be further co-ordinated into a regimental one, and the process repeated at formation level. Some DFs might be registered, and in Burma most were and often as close as 25 yards from the forward infantry positions.
DF fire plans were by their very nature 'on-call'. However, several targets were often grouped together and called as one. By 1943 it was generally recognised, at least in the European theatres, that DFs had to be fired by at least a regiment. Generally a DF was a standing barrage of one or two lines. Stonks were widely used as DFs. Standing barrages were also use for blocking purposes in attack fire plans, sometimes as three sided box barrages.
CP and HF targets were usually planned at regimental or higher levels. The first typically involved heavy concentrations, either predicted or observed using air-burst ranging or an AOP. HF usually involved a section, troop or battery and was almost always predicted, although sometime important targets that were regularly harassed might be registered after being ranged. The key to successful HF was to avoid predictability in the times or places of targets and the Germans learnt that the British tended to stop firing at meal times.
Fire planning used barrages or concentrations, and these together with smoke screens could all exist in one fire plan. Targets in a fire plan were registered or predicted. They could also be on a timed programme or on-call. The fire plan could be a simple as a FOO ordering a concentration to neutralise a target in 15 minutes time through to a corps fire plan involving 25 regiments firing a barrage 4 miles wide lasting several hours and planned days ahead. Larger fire plans were also used and in the last months of the war included a substantial ‘pepperpot’ component. This was the term for extensive use of non- field artillery fire. It included LAA, tanks, mortars and medium MGs.
Fire planning and its use and processes evolved continuously throughout the war, with the general goal of speeding up their preparation and increasing their flexibility. Quick fire planning techniques for use in support of company and battalion attacks also emerged. Although there was a stage when entirely on-call attack fire plans were popular, this was short lived and the accepted tactic in European theatres became a mix of time scheduled and on-call targets. On-call fire plans were preferred in Burma because of the difficulties in estimating movement time through jungle. Silent fire plans were also used, particularly for night attacks, they generally used on-call concentrations fired when the enemy discovered the attack.
Fire plan orders were issued as map traces annotated with times and rates of fire, task tables that gave target map references with engagement details, or for very simple fire plans verbal orders sent over line or radio. The fire planner was the artillery commander with the tactical commander of the operation, although for higher formation fire plans the detailed work being done by the artillery commander's staff. In all timed fire plans engagement times were ordered to the whole minute.
The barrage tended to be the main feature of British attack fire plans, with concentrations fired in and outside it. Most of the effort went into CF, ie neutralisation. There was usually a preparation element to cause casualties and damage, and HF tasks might be included if resources allowed, but were unusual. DFs were planned to help protect captured objectives from counter-attacks. CB targets were engaged, including the use of bombards. Counter-AA targets, called ‘Apple Pie’ in European theatres, were included in major fire plans when air support was incorporated. As the war progressed, fire plans of concentrations became common, initially the guns fired with lines of fire parallel as at multi-battery opportunity targets. In the last months of the war in NW Europe major fire plans made great use of stonks and standing barrages as concentrations. In large 'deliberate' fire plans some targets would be selected by the attacking battalions and their BCs. These were sent to the artillery commander' staff for co-ordination and incorporation in the plan.
Smoke screens were used in fire plans, they could be predicted, although a ‘tester’ to confirm the local wind was often used. Screens could be multi or single battery and positioned about 250 yards from the enemy to be blinded. Gun aim-points were placed on a linear, with the distance between them depending on the wind direction. If the wind was along the line of the required screen then points were 300 yards apart, if across the line they were 75 yards apart. Whenever smoke was used there were alternative HE targets in case the screen was ineffective. One technique was to create a lane a few hundred yards wide between two screens that screened tanks from defiladed anti-tank guns, if the wind was favourable these screens could be rolling.
A barrage was a belt of fire that could be stationary (standing), for example as a defensive fire (DF) or moving in front of the assaulting troops. They were structured on unit lanes with lines across them. In a barrage the guns fired at lines (ie linears), a troop's guns’ aim-points spread equally along each line’s troop lane width. This involved the CPs in each battery calculating the range and deflection for each gun to its aim-point on each line in the barrage that it had to fire at. Normal practice was to rest one gun at a time in each troop for at least 10 minutes per hour from 45 minutes after the start of the barrage, during this time they conducted quick sight tests, cleaned and maintained the gun.
Moving barrages had as many lines as needed to achieve the depth required. Moving barrages could be either creeping, rolling or block. When creeping, each line was engaged in turn, when fire lifted from the front most line it moved backwards to the next line (a-a, then b-b, etc in Figure 3). In rolling, several lines were engaged at once (eg a-a & b-b, when fire lifted from a-a it went to c-c). A block barrage had several lines engaged simultaneously and all lifting together to a new block (eg a-a, b-b & c-c lifting together to d-d, e-e & f-f). There were procedures for putting turns between lanes to give a crooked barrage. The 'echelon' method kept the lines parallel while the 'wheel' varied the distance between lines.
A 25-pdr troop could effectively cover a lane with 140 yards maximum width, lines were usually 100 yards apart. For a creeping barrage normal practice was for a field regiment to engage a regimental lane two batteries wide (560 yards maximum), with the third battery superimposed across the full width of the depth lane (ie open on b-b in Figure 4). For a dismounted infantry assault a regimental lane was normally 400 yards wide, the full width being used with armour.
Figure 4 – Regimental Moving Barrage
The opening line (a-a in Figure 4) was always positioned in front of the enemy’s most forward positions. Medium artillery had to engage lines at least 300 yards (d-d in Figure 4) back from the opening line. Field gun safety distances for dismounted infantry were 150 yard if the line of fire was overhead and 200 yards if fire was from a flank. The opening line was engaged for long enough for the assaulting troops to move from their start line to within 150 or 200 yards, then fire lifted to the next line. Creeping was normally used for dismounted attacks, rolling for tank and mounted ones. Large barrages normally had pause lines to enable the assault to catch up if it had lagged. From late 1944 LAA fire (tracer) was often used to indicate the boundary of the barrage and key lanes within it.
Various techniques were used to vary the pattern of a barrage, for example it might start on the back line, move forward then move back again. This was sometimes called a 'dragnet' barrage. False and different sequences of lifts were used if a barrage was repeated, ie used for preparation as well as covering fire. One goal was to try to get the enemy into their battle positions and fire at them again, this might be repeated to lull them into staying under cover when the real lift came. This technique was also used with concentrations.
The main planning issue was to deliver sufficient intensity of fire, a matter of density and duration. This meant the appropriate rate of fire onto each line for sufficient time, when time was governed by the rate of advance. If the advance was fairly fast then it might be necessary to engage more than one line at a time without counting the superimposed units. However, a problem with deep barrages was 25-pdr range, maximum range was some 13,400 yards with charge super but the guns overheated after about 40 rounds at this charge. This meant that barrages were limited to charge 3 and a maximum range of about 11,500 yards. The solution used was to engage the deep lines with medium artillery.
1942 planning times for units to prepare barrages, from the commander issuing orders, were three hours for regimental, 10 to 12 hours for a division and 24 for a corps. These times include deployment and survey but excluded any ammunition dumping. For a quick (as opposed to ‘ordinary’) divisional barrage, where the guns were already deployed, it was two hours. For a regiment 60 to 80 minutes assuming no more than 10 lines. Timings for fire plans of concentrations were not greatly different, although it would depend on the number of concentrations, analogous to the number of lines in the barrage. In either case British practice was to prepare written proforma with data for each gun, the Gun Programme, in all but the most simple fire plans.
Barrages could be entirely predicted to achieve surprise, as was the case at Cambrai in 1917. Registration was essential if firing units were not on a common survey grid. At least one point in a barrage was registered. For a simple straight line barrage it was one point, usually a junction of line a-a and a lane boundary, but it could be a clearly defined point within a lane. For barrages with an irregularly shaped line a-a, changing direction at lane junctions, then each direction changing junction and the outer-most lane edges at a-a had to be registered. Fire plans of concentrations might need considerably more registration because each concentration was a separate target.
A characteristic of all British fire plans was 'superimposed units' to provide a reserve. These were used to engage on-call targets, particularly DFs, or even entirely unplanned ones. The doctrine was that they could be removed from a scheduled task without significantly affecting the success of fire on that task. For smaller fire plans they were usually the direct support battery or regiment of the battalion or brigade making the attack because observers had the most direct communications with them.
Targets in fire plans were normally fired ‘time on target’ (ToT) from late 1942, care and time being taken to ensure synchronised time. Large multi-regiment opportunity targets were often ordered ‘engage at’, in which very precise time synchronisation was less important. For opportunity targets involving about one regiment the observer normally ordered them to fire when sufficient batteries had reported ready. Alternatively the observer could control the moment of firing by use of the commands 'fire by order' then 'fire' at the appropriate moment. However, by late 1944 ToT was widely used for large opportunity engagements, with the batteries' clocks being synchronised from routine time signals broadcast by the BBC. When own troops' safety was a consideration the observer could also order 'no rounds after . . . .' (a particular time).
In April 1945 2 NZ Division made a series of divisional attacks in N Italy while acting as 'point' for 8th Army. The fire planning for each of these was probably the epitome of the 'art' involving up to 15 regiments under the CRA's command with the complete artillery plan being made and executed in around 24 hours. Although they were all different, typically the barrage component was about 4000 yards wide and 3000 yards deep. Up to 8 regiments fired dragnet creeping barrages of over 30 lines, each with different lift sequences. In between the barrages the field regiments switched to HF tasks. Other regiments and heavy mortars fired concentrations within and around the barrage lanes and a reinforced AGRA fired CB and CM tasks. Naturally there was a comprehensive DF plan.
In 1941 Quick Barrages were introduced at regimental level using standard layouts and CP templates. They were followed in 1942 by quick regimental fire plans, enabled by the growing and successful use of radio communications and multi-battery targets. Typically, such fire plans were used to support quick battalion attacks. It's not clear if the techniques were ever used by regimental commanders to support brigade actions, and the fireplan for a brigade attack was sometimes developed by the CRA and his staff if it involved several regiments. Quick fire planning became one of the most notable features of the British artillery system.
Quick fire plans are a consequence and benefit of having the batteries' senior officers forward. Their characteristic was that all the orders were sent by radio, which was quick; no traces, schedule or 'hardcopy' target lists were distributed. This meant that they had to be simple and relatively small scale, and so required reduced preparation time.
The critical success factor was for the supported battalion commander and the artillery commander, usually the BC when affiliation had taken root, to plan the targets together by looking at the ground where they were. It was usual for key targets to be registered, the tactical circumstances usually meant that total surprise was’t an issue. The BC usually deputed registration to one or both of his observers.
As the war progressed the techniques and procedures for regimental or ‘BC’s’ fire plans evolved, and continued the obsession with speed. The time needed to develop them depended on the number of targets. They were particularly useful when operations turned to pursuit or during advances against light opposition. They were usually concentrations using a mix of timed and on-call targets. Increasingly battalion mortars were included in quick fire plans.
FOOs used quick fire plan techniques to support company/squadron actions or perhaps on-call for a patrol. Typically these fire plans comprised no more than a handful of targets, often using just the FOOs own battery.
Quick barrages used simplified procedures. Written orders and traces were not used, details being given verbally by radio, lanes did not turn or alter in width, each troop’s angle of sight remained the same throughout the barrage and templates and tabulated data were used in CPs. Since the quick barrage was less accurate, the start line was normally 500 yards from the opening line, so fire on that line had to last longer while the assaulting troops closed to the right safe distance.
Modification techniques were introduced so that timings could be altered if the infantry’s progress was delayed or accelerated. Three basic states for modifications were established; either no modifications allowed, modifications by an artillery observer from observations or modifications by the supported arm through a BC or FOO.
1943 planning data is shown in Table 2, the safe distance was for a line of fire parallel to the front of the assaulting troops. There were some differences post war.
Table 2 – Planning Data (yards)
|
Term |
25-pdr |
3.7" How |
4.5" Gun |
5.5" Gun |
155-mm Gun |
7.2" How |
|
Frontage covered by HE shell |
35 |
35 |
55 |
70 |
70 |
100 |
|
Safe Distance |
200 |
200 |
350 |
400 |
400 |
700 |
The need for the infantry to ‘lean’ on the barrage had been well established in WW1. Indeed the French considered that the attacking infantry could expect 10 – 15% casualties from their own artillery fire if they were about the right distance from it, and once in that war the British order was to keep 25 yards from the barrage! More generally the British took the view that to reduce casualties from defenders to the absolute minimum the assault had to reach an objective within about two minutes of fire lifting from it. More than this and the enemy had time to decide that the fire had lifted and then re-adopt their battle positions. Obviously poor quality troops took longer, and it also took longer for defenders in deep bunkers or cellars to get to their fighting positions. One technique used to help the assaulting troops was to insert pause lines into the barrage, on which fire would dwell to give them an opportunity to catch up if necessary.
The subject of safe planning distances needs further explanation. Figure 5 shows the lethality pattern for a 25-pdr HE ground-burst shell with angle of descent 20º and the percentage casualties to men standing in the open around the point of burst of the shell. At higher angles of descent the ‘butterfly’ pattern is less pronounced and the lethal area becomes more circular as it approaches 90º. Outside the ‘wings’ there was still a very small chance of a casualty, obviously this increased as more shells were fired. The safe distances were planning distances providing an acceptably low chance of a casualty, although higher than would be acceptable in peacetime.
Figure 5 – 25-pdr Lethal Area
|
The 20º angle of descent corresponds to ranges as shown in Table 3, apart from charge Super that was not used below a range of 10,500 yards. The 50% zone is two probable error (PE) and the 100% zone, in which all shells will fall is eight probable errors, four PE either side of the mean point of impact (MPI). Troops following a barrage could therefore expect a few shells from guns at a range of 7,000 yards to fall up to 40 yards short of the MPI. Statistically, 2% of shells would fall between 30 and 40 yards short from the MPI, assuming there are no round to round errors at the gun. The safe distance allowed for the worst case so if the PE was small and fire overhead then assaulting troops could get much closer than 150 yards. This subject is explained more fully in 'Effects and Weight of Fire' and 'Errors and Mistakes'.
Table 3 – Example 25-pdr Ranges and Probable Errors
|
Charge |
Angle of Descent |
Range |
50% Zone (range/line) |
Max range for charge |
|
1 |
20º |
2,600 yds |
60/2 yds |
3,500 yds |
|
2 |
20º |
5,000 yds |
30/2 yds |
7,500 yds |
|
3 |
20º |
7,000 yds |
20/3 yds |
11,500 yds |
|
Super |
35º |
11,000 yds |
50/6 yds |
13,400 yds |
The difficult part of a barrage was planning the timings for the rate of advance and for the assaulting troops to maintain the planned rate of advance and so keep close to it. This was exacerbated by the inability to modify a large barrage once fire was opened, apart from fire pausing on particular lines 'just in case'. The problem was the sustainable rate of advance to keep up with the irrevocable movement of the barrage.
In 1918 the normal rate was 100 yards in four minutes and between the wars it was fixed at three minutes on the basis that infantry loads had lightened. In mountainous terrain, such as Italy, 100 yards in 15 minutes proved unachievable. In Holland in 1944 a rate of 100 yards in five minutes held up the infantry. However, a safe distance of 150 yards and a bogey time of two minutes meant a rate of 100 yards in 80 seconds!
There were four alternatives: a barrage of such density and duration that the defenders were demoralised to the extent that they lost interest in fighting for an extended period after it lifted, a shell with a smaller safe distance, greater risk by getting closer to the barrage or faster movement. In NW Europe it was found that tanks, either alone or carrying infantry, and carrier-borne infantry could advance at 150 or 200 yards per minute by day and 100 by night. The first, sustained demoralisation was also achieved on occasions.
Concentrations weren’t the complete answer either. For a start there was still the problem of getting the infantry to the safe distance from the concentration then lifting it and the time it took them to secure their objective. An added problem was the size of the concentration in its two dimensions, when fire lifted the assault might be several hundred yards from the rear-most positions on the objective. There were several possible solutions to this:
In 1943 it became policy that a concentration should not be more than 200 yards deep when used for CF and this tended to lead to parallel stonks in larger fire plans. They could be engaged simultaneously or sequentially. When concentrations on the objective ceased it became usual to ‘lift-out’ onto targets surrounding the objective, to prevent interference from mutually supporting positions and forestall counter-attacks.
The amount of fire used on a target was a matter for the originator or observer. There were Standing Order rates and quantities for DFs, and agreements with the RAF for Arty/R. However, the basic approach was to rely on the observers’ experience and their observation of the effects of fire on the target. It was generally considered that short bursts of fire were the most effective, as in the bombard procedure. However, bursts don’t provide CF, which needs continuous neutralisation. Obviously the thinking behind the 'short burst' doctrine was to repeatedly catch the enemy by surprise with the goal of causing casualties.
The normal order for 'fire for effect' against opportunity targets and concentrations in fireplans was "nn rounds gunfire". However, for multi-regiment targets a ‘scale’ was usually ordered. Scale 3 meant that every gun had to fire 3 rounds, if a battery in a regiment was engaged on another target then that regiment made up for the missing battery by having its other batteries fire extra rounds. Similarly in a battery, division or corps artillery.
In fire plans, when targets or barrage lines had to be engaged for a particular duration, 'rates of fire' (rounds per minute) were ordered with a duration in minutes as follows:
Table 43 – Rates of Fire – Rounds per Minute
|
Term |
25-pdr |
3.7-in how |
3.7-in HAA |
105-mm how |
4.5-in gun |
7.2-in how |
7.2-in how Mk 6 |
155-mm gun |
8-in gun |
240-mm how |
|
Intense |
5 |
5 |
12 |
5 |
2 |
1 |
1 |
2 |
- |
- |
|
Rapid |
4 |
3 |
4 |
4 |
1½ |
½ |
1 |
1 |
1 |
2⁄3 |
|
Normal |
3 |
2 |
3 |
3 |
1 |
1⁄3 |
½ |
½ |
½ |
1⁄3 |
|
Slow |
2 |
1 |
2 |
2 |
2⁄3 |
¼ |
1⁄3 |
1⁄3 |
1⁄3 |
¼ |
|
Very Slow |
1 |
½ |
1 |
1 |
1⁄3 |
1⁄8 |
1⁄6 |
1⁄6 |
1⁄6 |
1⁄8 |
‘Gunfire’ meant that rounds were aimed and fired as quickly as possible. For 25-pdr this was about 6 - 8 rounds per minute. This could only be sustained for a few minutes, intense rate was the maximum sustained rate that the guns could achieve without overheating.
The major question was whether to use observed (ie ranged) or predicted fire. The latter gave surprise and should, therefore, be more effective for causing casualties and not compromising an impending operation in the case of a fire plan. It also took longer to prepare to fire. However, predicted fire that took the enemy by surprise but missed the target was totally ineffective. In fact there is evidence that missing was worse than not firing because being missed enhanced the target’s morale. Of course if it could be observed it could be corrected, but the result was no better than ranged fire, more ammunition was used and it may or may not have been quicker overall.
Operations research at the end of the war suggested that the accuracy of predicted fire had been poor, as few as 7% of predicted engagements were effective. This indicates that predicted fire was not the best solution. Of course one answer was to predict large multi-regiment concentrations and allow the natural spread of MPIs to ensure adequate coverage of the target. For further detail see Mistakes & Errors.
Another approach was to register a target and engage it again later with predicted fire to achieve surprise. However, this depended on the target staying in its registered place.
The usual criticisms of barrages were that they:
Their great advantage was that they removed the need to properly identify every enemy position, this made the planning process quicker than identifying and planning every possible target, which was the case for a fire plan of concentrations. For the frontages and relatively high troop densities of WW2, and the objective of neutralisation, barrages were a practical proposition. Whether barrages were quicker or slower to produce in CPs depended on the number of targets or barrage lines.
By the final year or so of the war radio communications and modification procedures made it possible to modify smaller barrages by 'dwelling' if the infantry got behind or speeding up if progress was faster. However, the lag inherent in hierarchical net-based radio systems meant that this was not practical for large barrages.
Although it was seldom a problem for the British in WW2, prolonged firing in a barrage could make guns very vulnerable to the enemy’s CB organisation and retaliation.
The basic problem with timed targets was synchronisation with the assaulting troops, although this was less of a problem if timings could be quickly and easily modified. On-call targets provide great flexibility, but even an on-call target needed a duration if the goal was neutralisation.
There is little point in having on-call targets for CB and preparation fire before the assault starts, apart from those to attack HBs that become active. Since air forces also liked precise timing counter-AA targets were almost always timed. Offensive operations, and phases within them had time, the first being H-Hour when the assault troops crossed the start line. Clearly some targets would be attacked at this point and so be timed. However, no plan survives H-Hour (the time when troops cross the start line) unchanged so flexibility is essential thereafter.
BCs with their directly supported battalion commander made quick fire plans, they also co-ordinated their observers in the use of their battery. CRAs and their staffs made formation fire plans and their HQRAs allotted units for Uncle and Victor targets requested by un-authorised observers. At brigade/regiment level the CO at Brigade HQ was the fire planner but the adjutant away at RHQ allotted batteries for Mike targets. This does not seem to have caused problems.
Most British guns were just that, guns not howitzers. A particular problem for applying fire emerged in Italy and Burma due to the mountainous terrain and consequent need for upper register fire that could get at targets tucked in valleys and behind steep hills. This was achieved for the 25-pdr by introducing intermediate charges, a modified sight mount and raising the wheels above the spade level (eg by digging a trench for the spade), a cranked trail was introduced on the 25-pdr Mk 3 carriage.
The British undertook considerable research, using studies, trials, experiments and analysis of the results of enemy attacks on British forces and British attacks on the enemy, into the effectiveness of artillery fire and how much was needed against particular targets. Although tabulated data was produced it was never used in the field (apart from the fire plan for D-Day). For details about weight of fire see 'Effects and Weight of Fire'.
One of the early results was to prove that the old wounding criteria, based on pre-WW1 French research, of 58 foot-pounds was excessive. This led to new criteria being adopted. It's unclear if any new artillery ammunition using the new criteria was developed during WW2, the most likely would have been the 5.5-inch 80 lb shell and 4.2-inch mortar bomb.
Another result was the operations research scientists defining the effects of artillery fire and the densities and intensities of fire needed to achieve these effects. These are shown in Table 4 and enable evaluation of the effectiveness of fire plans and opportunity targets. First the defined the effects:
|
"Neutralising" |
To prevent enemy movement and observation, and in cases of greater effect to prevent the effective use of enemy weapons. Effect to last during the bombardment. |
|
"Morale" |
To produce, in addition to neutralisation, a lack of will to resist continuing for some time after the end of the bombardment. |
|
"Lethal" |
To kill or wound enemy personnel. |
|
"Material" |
To destroy or damage enemy equipment. |
Next the estimated weights of fire to achieve these effects. These are in terms of 25-pdr equivalence and shown in the next table.
Table 5 – Weights of Fire
|
Effect |
25-pdr Equivalent Effects |
|
"Neutralising" |
0.02 - 0.08 lb/sq yd/hr |
|
"Morale" |
0.25 lb/sq yd/min for 15 mins (*note) |
|
"Lethal" |
0.1 lb/sq yd gives |
|
"Material" |
0.1 lb/sq yd gives |
Note - the 15 minutes for demoralisation is suspect, it was based on one attack, at Wesel in 1945, before this it was considered that at least 4 hours of fire was needed.
Lastly, it's useful to note how vulnerability changes with posture because it suggests the relative amounts of fire needed in different circumstances. The following estimates the relative risks of becoming a casualty to ground-burst shells on ‘average’ ground:
|
Standing |
1 |
|
Lying |
1/3 |
|
Firing from open fire trenches |
1/15 – 1/50 |
|
Crouching in open fire trenches |
1/25 – 1/100 |
There does not appear to be any study of British artillery casualties in WW2. Apart from a detailed study of statistical sources this means relying on the anecdotal accounts in unit histories. Since most men were in the gun areas then its worth considering them first. The total RA losses, according to the 'Roll of Honour', were about 31,200 for all parts of the Regiment, this is about 22% of British Army's killed and those still missing in 1946. At the end of 1944 British Army strength figures showed about 1000 officers and 14,000 other ranks from field artillery (including anti-tank) as prisoners in enemy hands.
Casualties in gun areas occur from ground attack, air attack or CB fire. The first seems to have been a feature of the early years of the North African Campaign and Burma, but overall figures are not recorded. Air attack was always a threat but does not seem to have been a significant one after 1943 and disappeared entirely in the final months of the war as photographs of guns wheel to wheel in open fields show. Effective CB by WW1 criteria also seems to have been rare, although it was sometimes heavy in N Africa and Italy. The Werhmarcht's artillery was but a shadow of its WW1 predecessor because the Luftwaffe had promised to provide all necessary firepower. By the time this was exposed as wishful thinking Germany no longer had the resources to re-create a powerful field artillery arm (resources went to AA artillery to counter the allied bomber offensive) and so concentrated on mortars, which posed a minimal CB threat. Although in Normandy some 70% of British infantry casualties came from mortar fire. Japanese artillery seems to have been unable to deliver fire above battalion level and there do not seem to be any accounts of effective CB fire.
The most exposed elements of field artillery were the observers. Unit accounts suggest that they may have suffered high casualties in NW Europe 1944-5. For example one battery account recorded having 10 observers in the period. If all the losses were due to casualties then this is a loss rate of about 40% per month. It's not known if this was representative but it does tally with accounts from other units. Losses in other theatres do not seem to have been this high.
Although manpower shortages were a feature towards the end of the war, the war establishments of British units included their 'First Reinforcements'. This, together with cross-training meant that at least some casualties could be replaced very quickly.
1. Speed was an obsession when responding to calls for fire; the system delivered mobile firepower very quickly. 'Rounds of the ground' was what mattered, the sooner they were there the sooner beneficial effects started.
2. Neutralisation was the predominant objective of artillery fire in offensive operations, and the 25-pr had been designed for this role.
3. The senior officers of artillery units were with the supported arm, with the following beneficial consequences:
4. From the middle of the war onwards corps became the primary level for artillery command, with control of firepower devolved to the appropriate level. The British system was to move firepower not fire units. This system was characterised by the maxim 'command at the highest level, control at the lowest level'. The important result was that command and control were separated and a commander did not need to command artillery to have its firepower available. 'Unity of command' was not a barrier to the effective control of artillery mobile firepower.
5. Quick fire plans by BCs and FOOs emerged as one of the distinctive tactics of the British artillery system, and remain so to this day.
6. There was an effective CB system, but the weaknesses of German and Japanese artillery meant that it was seldom fully stretched. Hostile mortars remained a problem.
7. Gunnery drills and procedures were well designed and standardised in detail to facilitate speed and error prevention, with options to enable tactical flexibility.
8. The artillery doctrine and practices were sound, able to exploit changes in technology and adapt to the conditions of different theatres.
9. Large batteries, the 8 gun battery was unique.
The most experienced divisional commander of WW2, the New Zealander Lt Gen Freyberg VC (he commanded 2 NZ Div from 1940 to 1945 apart from two brief periods when he commanded ad hoc NZ corps) regarded the Royal Artillery as the best trained and best led part of the British Army.
The British artillery in France in 1940 was technically competent, but the BEF was less than 10% of the allied forces and unprepared for German tactics and operational tempo.
Things went wrong in North Africa from early 1941 until the arrival of General Montgomery in 1942. In essence, poor tactics meant proven artillery principles and doctrine were mostly ignored. Montgomery, whose 1940 experience convinced him that artillery concentrations were a key to success in fighting Germans, directed CRAs to have centralised control of their divisional artilleries and to use them as 72 gun batteries.
Predicted fire was insufficiently accurate and was exacerbated by longer ranges to targets than in WW1. The main causes were stale meteor data, target location errors from inaccurate maps, and ammunition that invalidated calibrated MVs.
In NW Europe 1944-5 the high casualty rates among infantry commanders (around 30% per month for battalion, company and platoon commanders, of whom about 1/3 died) meant that battalions had difficulty maintaining their expertise, particularly in using the covering fire provided by a barrage and directing fire via a FOO. The 2nd NZ Division, often considered the best allied division in Italy, maintained their expertise and were masters in using barrages effectively.
Having only two observers for four companies meant that FOOs had to keep moving around, and moving around increased casualties. In Burma it was a serious problem only solved by detaching men from the gun position. Medium and heavy batteries had observers, who normally operated as OPOs for their own batteries.
Towards the end of the war and immediately afterwards there was criticism that too much fire was used and that concentrations were unnecessarily large. The operational research evidence suggests that the former was not so, although it depended on what effect was wanted, and barrages were undoubtedly wasteful of ammunition. That concentrations were too large may be true, although it can be argued that it probably saved lives and was therefore justifiable.
From the 1920s onwards British commanders realised that they had to avoid casualties on the scale of WW1. This meant using firepower and artillery was the primary source of it. The low number of casualties in the British Army, compared to WW1, indicates that this goal was generally achieved.
Change and continuity characterised the 25 years after WW2, with RA in action in Korea, Malaya, Kenya, Suez, Radfan, Brunei and Borneo. In 1950 Target Grid Corrections were adopted for ranging. This meant that corrections were ordered as distances around the line observer-target (OT), Left or Right to get ranging shells onto OT, then Add and Drop to bracket the target. GT or any arbitrary line could also be used if required. Observers no longer ordered a BT range and switch. With this change the British soon dropped the use of zero lines and adopted ‘real’ grid bearings.
Unit designations remained unchanged apart from survey regiments being re-designated ‘observation’ and subsequently ‘locating’. However, HQ batteries were introduced into all regiments and the signals section underwent 'gunnerfication', with the signals officer becoming RA and the R Signals element being reduced to rear link communications only. Off-setting this, the RA repair tradesmen (gun fitters, vehicle mechanics, etc) were transferred to REME and LADs enlarged to absorb them as well as the 'REME attached' from regimental establishments. Driver-mechanics were abolished. The rank of lance sergeant was abolished but additional sergeants were established.
The size of RHQ and HQ battery steadily increased while gun batteries became smaller. There was a major contraction in the number of regular units in the early 1960s when conscription ended and of TA units in 1967 when TA field formations were abolished.
Post WW2 analysis showed that predicted fire lacked accuracy and various actions were undertaken to improve it. Most notably an improved correction of the moment graph, better charge temperature measurement, revised calibration procedures and improved CP processes for producing firing data. This improvement process continued with the first MV measuring radar appearing in the 1960s to the late 1980s when one was fitted to every gun. Survey also improved with every battery receiving a gyroscopic orienter in the mid 1960s and a full inertial 'position and azimuth determining device' around 1980.
Responsibility for artillery meteorology was transferred from the RAF to RA and appropriately resourced divisional met detachments created that could continuously produce good quality meteor messages.
Quick fire plan procedures and processes were further evolved, and there were various other minor changes to some procedures and many refinements to drills. The term 'deliberate fire plan' was introduced for the traditional and slow type.
After the war there was argument about the replacement of the 25-pdr. The war in Europe led one side in this argument to seek a smaller calibre gun since neutralisation was the need and a smaller gun meant a smaller safe distance, which meant less exposure time for attacking troops when fire lifted. Those from the Far East wanted bigger calibres for destroying bunkers. In the event an 85-mm 20-pr was developed. However, NATO had standardised on 105-mm as the smallest calibre, and in any case NATO was defensive. Offensive operations were out of fashion so casualties and damage, not neutralising, capabilities were required. Larger calibres also offered greater range, which was required for concentrations as battlefield density decreased.
Mils were increasingly used for angular measurement with new equipment, and in the late 1950s they were adopted throughout the army (except aircraft compasses) to replace degrees and minutes. During the 1960s 25-pdr and 5.5-inch were converted to mils, which divided a circle into 6400 mils instead of 4320 divisions of 5 minutes, slightly improving precision at longer ranges. Most significant was the introduction of the plotter to replace the artillery board. This instrument enabled fast and accurate production of map data for any range and bearing, and conversion of target grid corrections to bearings and ranges. On it gun positions, targets and corrections were plotted at 1:2000 scale. The plotter, a great invention, lasted until the arrival of computers in 1970, which was accompanied by a data display at each gun connected to the CP by line or radio. British SPs had been equipped with radios in the mid '60s.
Predicted data was produced for all targets, although ranged ones were still ordered as a 6-figure map reference (ie nearest 100 yards/metres). In the late 1950s field and medium batteries reverted to 6 guns and the number of officers in a battery reduced from 10 to 7. Batteries were also equipped with the 'high roof' Saracen FV610 RA armoured command post. CP procedures were revised for a single working CP in each battery although each had two CPs giving a reserve, a resource for fire plans and enabling slick deployment drills. In 1981 some field batteries became 8 gun again but the single working CP was retained.
In 1957 the Air OP squadrons became the nucleus of the new Army Air Corps (although this Corps has WW2 antecedents). In the 1960s many field regiments had their own air troop of observation helicopters.
In some campaigns of the 1950s and '60s light anti-aircraft gunners manned sections of 4.2-inch mortars in various active theatres, although these had equipped light batteries, most notably in Korea.
In about 1960 target acquisition capability advanced significantly with the introduction of new equipment. An excellent mortar-locating radar (FA No 8, Green Archer, with a silenced generator and Foster scanner that eliminated the need to track the bomb), a long range ground surveillance radar (GS No 9, Robert, mounted in a Saracen) and an unmanned aircraft the SD-1 drone. In the next decade effective radio-link sound ranging (radio replaced line) was finally introduced. The mortar-locating radars and a small counter-mortar staff were a troop in each field regiment, again reflecting the lessons of WW2.
British observers had rarely used anything more that hand held binoculars as observation aids. However, they were early adopters of more advanced devices for every observer: radar (GS No 14) (1975), laser range finder and night observation device (large image intensifier) (1976), position and azimuth determining system (inertial navigator) (1981), thermal imagers (1990). Observers (but not BCs) affiliated to armoured regiments were equipped with tanks (Centurion Mk12) until 1979. However, the WW2 mismatch in the number of observers in a battery and the companies/squadrons continued, although TA observation batteries were formed to provide a third OP/FO party for most regular batteries.
In 1965 the Australia, UK, Canada, US (ABCA) common artillery procedures and terminology came into effect for calls for fire between observers and CPs, and subsequently became NATO procedures. This resulted in a complete change in terminology and some changes in procedures.
Speed in answering calls for fire remained an obsession. In about 1970 a US review team visited Vietnam and found US batteries generally took about five minutes from receiving a call for fire to firing the first round. They then visited the Australian and New Zealand batteries using British procedures, they had gun rules for their 105-mm M2A2, and found them never taking more than 90 seconds, usually delayed by the need for air clearances.
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Copyright © 2001, 2002 Nigel F Evans. All Rights Reserved.
