Introduction

This page summarises the main features of the British field artillery system used in Commonwealth armies, a system to deliver mobile firepower, where the firepower rather than the guns are manoeuvred.  It provides links to other parts of this site that give more detail.  A 9 point list of the important characteristics and some quotations are also given here.  A short description of the distinctive fire control method is given here.

The Royal Artillery was responsible for field artillery including survey, anti-tank, anti-aircraft (AA), coast artillery (anti-ship) and maritime artillery (air and surface defence of merchant ships at sea).  This site is primarily concerned with field artillery but has an anti-tank page.  A brief summary of anti-tank and other non-field artillery is at the end of this page.

All links on this page are internal to this site.

Organisation

• Throughout the war a troop of four guns was the basic fire unit in most batteries,
• a troop was commanded by a captain.  
• a troop was divided into two sections, each of two guns, a single gun was a 'sub-section'.
• Most batteries comprised two troops,
• a battery was commanded by a major.  
• Field regiments  (battalions) had three batteries except for the first 18 months of the war.  
• a medium regiment had two batteries,
• heavy regiments had four batteries, but only four guns in each,
• in most, except heavy regiments, all batteries had the same type of gun,
• a regiment was commanded by a lieutenant colonel.
• There were three field regiments in an infantry division under command of the divisional Commander RA (CRA), a brigadier.  
• He had a small staff at HQRA that was part of divisional HQ.
• His principal staff officer, a major, was the 'Brigade Major Royal Artillery'.
• There was a Survey Regiment, primarily for counter battery target acquisition using sound ranging and flash spotting, in each corps.
• The survey regiments also undertook artillery survey to support units' surveyors.
• Meteorological  data was provided by air force teams attached to artillery units and HQs.
• Calibration  was a unit responsibility but special troops were formed to assist them.
• Each corps had a Corps Commander RA (CCRA).
• Above this level  the senior artillery officer (a brigadier or major general) was a staff officer not a commander.
• The CCRA had a small staff.
• In addition there was a Counter-battery staff.
• Medium, heavy and additional field regiments were available at corps and higher level and assigned as required.  In late 1942 most of these regiments were formed into Army Groups RA (AGRA) under a Commander AGRA (CAGRA).
• It was a principle that a formation or unit commander at any level only dealt with a single artillery commander (covering all field, anti-tank and anti-aircraft matters).
• In an infantry or armoured brigade after about 1941 a field battery commander was assigned to each armoured regiment of infantry battalion.  
• He normally accompanied the supported regimental or battalion commander.  
• His troop commanders normally accompanied the two forward squadrons or companies.  
• After about 1941 it became the practice for the commander of the artillery regiment supporting a brigade to accompany the brigade commander.  However, regimental HQ remained in the gun area.
• Regiments and most batteries were uniquely numbered by type,  however, within a regiment batteries were designated P. Q, R and S for fire control purposes.
• Air Observation Post (Air OP) Squadrons were RAF units commanded by an artillery officer with all pilots artillery officers flying light aircraft (Auster).
• Squadrons were first formed in 1941.
• There was normally one squadron per corps, except in Burma

Deployment

• A regiment's batteries normally deployed within about 2000 yards of one another.
• Regimental HQ was in this area, normally commanded by the regiment's Second in Command and operated by the Adjutant.
• Batteries deployed  with their troops usually separated by a very few hundred yards.
• Each troop  had its own command post and the troop position was commanded by its Gun Position Officer (GPO).
• There was also a Battery Command Post under the Command Post Officer.
• The senior officer in the battery area was The (battery) Captain.          
• He was not an XO and was primarily responsible for logistic and administrative matters and in the wagon lines.
• The battery and troop commanders were the battery's observers and did not deploy with the guns.
• Troops were given a zero line bearing, this was the same for both troops in a battery and often the same for all batteries in a regiment.
• The guns of a troop tended to deploy in a straight line at right angles to the zero line and 20 - 30 yards apart, curved lines were adopted in the desert and positioning each gun to provide good concealment, which usually meant a 'ragged' line, was used when the air threat required it or the terrain forced it.
• After unhooking the guns and unloading stores and ammunition the gun towing vehicles went to the wagon lines, usually a few hundred yards from the guns.
• Deployment drills ensured the guns were brought into action as quickly as possible, and without errors that could affect the effectiveness of their fire.
• Guns were oriented by:
• Aiming point method, or more usually
• Individual angles from their troop director.
• The regimental survey section delivered sympathetic fixation and orientation to each troop.
• This could be accurate to the map or this accuracy may have required survey data from the corps survey regiment.
• Accuracy could be updated using change of grid procedures .
• Sympathetic survey ensured the batteries of a regiment, division or corps could shoot together.
• Accurate survey enabled predicted fire against accurately located targets.

Application of Firepower

• The principles for the application of fire were:
• Cooperation with the supported arm (infantry or armour).
• Concentration of firepower (did not require concentration of guns).
• Surprise.
• Economy of force, which followed from concentration.
• The effects of artillery fire were:
• Neutralization (preventing the enemy doing what they should be doing, it only affected men and only lasted while fire was falling).
• Demoralisation, an effect of sustained attack.
• Casualties to men and destruction and damage of equipment.
• These effects were applied in pre-planned and impromptu fire to:
• Suppress the enemy to prevent them moving or using their weapons and equipment effectively.
• Cause casualties to the enemy and shake their morale.
• Destroy and damage structures and material.
• British use of pre-planned artillery fire in the all-arms battle was:
• In Attack:
• Artillery preparation – to cause casualties and damage before assault.
• Covering fire (CF) – to neutralize the enemy during the assault using barrages, concentrations or smoke.
• Counter-battery (CB) – to neutralize or destroy enemy artillery (also impromptu if permitted by CB policy).
• Harassing fire (HF) – hampering movement to the front, hindering the conduct of operations and reducing morale.
• In defence:
• Defensive fire (DF) - to cause casualties and damage to enemy attacks (also some types of impromptu fire).
• Counter-battery (CB) – to neutralize or destroy enemy artillery (also impromptu if permitted by CB policy).
• Harassing fire (HF) – hampering movement to the front, hindering the conduct of operations, and reducing morale.
• There were six types of impromptu fire.
• There were various shell and fuze types:
• High Explosive (HE) shells with Direct Action fuzes were the standard ammunition for all guns.  
• Graze fuzes, which gave a delay effect were also available.
• Mechanical Time  fuzes were only used for airburst ranging (but were the normal fuze for heavy AA).
• VT fuzes became available at the end of 1944.
• Other natures available for various guns included:
• Anti-tank shot.
• Base ejection  and white phosphorus smoke.
• Chemical.
• Star  (illuminating).
• Coloured flare and smoke.

Tactical Fire Control

This term was not used by the British Army but it's an appropriate name for the tactical arrangements to plan and direct mobile firepower using indirect techniques.   

• The principles for effective tactical fire control were:
• That the artillery commander and the tactical (eg infantry) commander must be co-located at each level of command.
• Artillery command must be well forward.
• Artillery command and control must be directly linked to the all-arms tactical plan.
• Artillery was assigned 'Under Command' or 'In Support' of a unit or formation.
• It was unusual to assign artillery units 'Under Command' of brigades or battalions, normally they were 'In Support' to these levels.
• Tactical fire control was an artillery commander's responsibility.  
• At battery and troop level commanders were normally forward with the supported arm and not at the gun position.
• An artillery commander at any level could order all the guns under his command to fire at a particular target.  He could also delegate this authority for a limited or extended period.  
• A troop commander (or his substitute) could normally order fire against an impromptu target to all of his battery.
• A battery commander could normally order fire against an opportunity target to all of his regiment.
• Targets were engaged with impromptu or planned fire.
• Impromptu fire emphasised speed to get shells on the ground as quickly as possible.
• Impromptu fire was used reactively against unplanned or opportunity targets.
• Often (it was the observer's decision) speed was traded for accuracy in calculating firing data for impromptu targets.
• Impromptu fire was almost always ranged, usually to the Battery-Target (BT) Line.
• The exception was a moving target, Gunfire was used for this.
• The use of impromptu fire increased throughout the war.
• An impromptu target could be registered for future use.
• Planned fire was used in fire plans and could be arranged hours or days before being used.
• It could be a barrage, concentrations or smoke screens, but usually a mixture.
• Targets could be programmed or on-call.
• Firing data was predicted. although some key targets or points could be ranged in advance and recorded.
• The capability to concentrate the fire of several regiments was practically limited to pre-planned targets until new procedures for impromptu targets were introduced in late 1942.
• From this time any observer could request the fire of any number of guns if he considered they were needed.  This request was sent to the HQ of the requested guns.  Certain observers could be authorised to order the fire of large numbers of guns.  For example a CCRA's Representative could order the entire corps artillery to fire at an impromptu target without asking the CCRA or corps HQRA.
• Commanders of medium regiments and batteries were often Commander's Representatives.
• Air OP pilots  were usually authorised for at least a regiment and often a divisional artillery.
• Almost all radios were HF, these had greater range than comparable VHF radios, which facilitated large concentrations of fire.
• Fire plans using planned fire to support major attacks were usually designed at division and higher levels.  
• In the early years divisional HQRA often designed the fire plan for a brigade attack in consultation with the brigade commander and field regiment commander.  
• Orders for these fire plans were issued in hardcopy lists and map traces.
• As the war progressed, brigade fire plans increasingly devolved to the field regiment commander unless a complex barrage was required.
• Fire plans using moving barrages to a timed programme were a feature of most major fire plans throughout the war.  
• Concentrations were also used in fire plans.  
• Barrages  could be moving or standing.
• Moving barrages were creeping, rolling or block and provided covering fire by neutralising the enemy.
• During preparation fire moving barrages could be 'dragnets'.
• Moving barrages could change direction.
• Standing barrages, usually used for defensive fire, were mostly on-call.
• Quick barrages, using a template were introduced for use a brigade or lower level.  However, as the war progressed it became increasingly usual for these lower level fire plans entirely to comprise concentrations.  
• The orders for these quick barrages and fire plans could be given by radio.
• Smoke screens  were used in fire plans and quick smoke shoots for impromptu targets.
• A troop normally fired with its gun barrels parallel.
• Gun lines of fire could be converged or diverged to concentrate or distribute the fire of a troop.
• Barrages, stonks and smoke screens required diverging lines of fire.
• In concentrations and battery targets all troops aimed their pivot gun at the same point.
• The amount of ammunition to be fired could be ordered in several ways:
• The normal method was 'nn Rounds Gunfire', each gun fired the ordered number of shells as quickly as possible'.
• Gunfire could be ordered with an interval in seconds between each gun firing in a battery, troop or section.
• An alternative to Gunfire was a specific number of rounds per gun per minute.  These rates were given names from 'intense'  to 'very slow', the actual number of shells depended on the type of gun.
• Scale was like Gunfire but each unit had to make up for any guns that were out of action or engaging another target.

Technical Fire Control

The term 'technical fire control' was not used.  It is used here to cover the gunnery procedures and methods used to attack a target.  The term 'observer' means a forward observation officer or observation post able to see a target.  However, it can also refer to a Counter Battery officer or other person ordering fire against a target out of sight.

• Units of measurement were yards for distance and degrees and minutes (usually graduated to 5 minutes) for angles.
• Speed of action and error avoidance was achieved by efficient drills and procedures.  
• The fastest possible response to observers' fire orders was a major goal, 'rounds of the ground fast' against impromptu targets usually took precedence over time spent ensuring great accuracy.
• The language of technical fire control was fire discipline, used between observers and command posts and between command posts and their guns.
• Fire could be ranged onto the target by an observer or predicted to hit a target without ranging.
• Corrections for each gun's variation in muzzle velocity from range table standard were always applied automatically without calculation because British guns had calibrating sights.
• Angle of sight  was always used with predicted fire but optionally with ranged fire.
• Accurate predicted fire  required the guns to be surveyed to the map grid and their targets accurately located.
• Impromptu concentrations required at least sympathetic survey between batteries.
• Predicted methods could be used with ranging, but this was unusual.
• The standard distribution of fire on the target was an approximate straight line at right angles to the line of fire.
• Guns applied their position corrections to achieve this.
• A battery's fire was only about a troop's width.
• Ranging was normally by two guns (a section).
• When ranging a battery or smaller the observer always ordered corrections as a new BT range and an angular switch in degrees and minutes, usually aiming to get the line of fire through the target then to bracket it.
• From 1942 ranging a battery or less allowed an observer to range fire on his OT line, but the ordered corrections still had to be relative to BT.
• When ranging for more that one battery the observer used a cardinal point bearing (NW, SE, etc) and distances to the nearest hundred yards.
• A ranged target could be registered by recording it.
• Firing data was reduced and the corrected map reference determined and could be circulated to other batteries.
• A registered target was always given a target number.
• The target numbering system indicated the extent of circulation of target data.
• Calculations were done from the position of the pivot gun, the right hand gun, of each troop.
• Map data (range and switch) was measured on the Artillery Board.
• Angle of Sight, if used, was calculated in various ways or taken from a graph.
• Corrections for non-standard conditions were calculated using Range Tables and graphs.
• A Datum Point could be used as a source of data for non-standard conditions.
• A Witness Point could be used as a source of corrections instead of calculation.
• Firing data ordered to the guns included:
• range in yards and switch from the zero line
• an angle of sight (optional) in degrees and minutes,
• ammunition, including fuze setting if applicable,
• if necessary, corrections to place the fall of shot in the required pattern.
• For impromptu targets their location could be ordered to the guns by an observer using any of the following methods:
• a range and switch from the zero line sent to the troop CP;
• the observer decided the type and quantity of shells, the Gun Position Officer decided which charge to use,
• after ranging the corrected range and switch could be transferred from the ranging troop to the other troop in a battery using the link procedure;
• this was the quickest method of engaging a target.
• By a 6 figure a map reference (100 yards/metres precision) to a battery CP;
• With a battery or less and this method the CP reported the BT range when they fired the initial ranging shells.
• a registered target number (ranged or predicted); or
• a correction from another target (recorded or immediately previous) using cardinal point(s) and distance(s).
• The last three of these methods could be used for concentrations of more than one battery.
• Corrections for non-standard conditions were not used unless the observer explicitly ordered them.
• Predicted fire always applied corrections for non-standard conditions (atmospheric conditions and propellant temperature).
• 8 figure map references (10 yards/metres precision) were used with cross-checking between battery and troop CPs in a battery.
• Angle of sight and corrections for non-standard conditions ere always used.
• Predicted fire was always used for pre-planned targets.
• Some targets in a fire plan could be ranged, although this could compromise surprise, or previously ranged and registered.
• Barrages mostly used predicted fire, although sometimes a point accurately known in relation to a quick barrage was ranged.
• The fire of each battery was evenly distributed across the width of its lane.
• The fire was aimed at a line at right angles to the axis of the barrage (ie not the line of fire).

Other Artillery

• Anti-tank artillery
• Anti-tank artillery regiments were formed in 1938 by converting regular and Territorial Army artillery field brigades (ie 'battalions').
• One regiment per infantry division and another per corps, mostly 4 batteries each with 3 troops of 4 guns.
• Initially mostly equipped with 2-pdr, replaced with 6-pdr then some 17-pdr and 3-inch M10.
• Anti-aircraft artillery
• AA was a very large part of the Royal Artillery.
• Units were either Heavy AA, Light AA or Searchlight.  Some batteries had 'unrotated projectiles' (rockets).
• At peak AA Command in UK comprised 12 AA Divisions in 3 AA Corps.
• LAA and HAA in field forces comprised a LAA regiment with each corps and division. and
• AA Brigades comprising LAA and HAA regiments assigned to armies and overseas theatres.
• Mostly equipped with 40-mm Bofors, including SP, and later some 20-mm Polsten for LAA, 3.7-inch HAA (fixed and mobile mountings),  some 4.5-inch in fixed AA sites in UK and overseas, and from mid-war some 5.25-inch in fixed sites in UK.
• Coast artillery
• Coast artillery was employed in fixed defences to defend ports.
• Armament varied from 6-pdr close defence guns to 9.2-inch counter-bombardment guns, with larger calibres at Dover and Singapore.
• Maritime artillery
• Maritime artillery was formed in 1940 to man surface and air defences on merchant ships.
• RA provided 40% of the men on 'defensively equipped merchant ships' (DEMS), the remainder were from the Royal Navy.
• Maritime regiments had troops or batteries stationed in ports around the world - from Sydney to New York, which provided depot type functions for men between voyages.
• Royal Marine Artillery
• During the first years of the war there was a Royal Marine Division including RM artillery equipped with 3.7-in How, this division was disbanded.
• During the D-Day landings and the following weeks RM assault batteries were equipped with Centaur tanks armed with 95-mm Howitzers, they were disbanded as planned in July/August 1944.

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