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.
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.
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.
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 a field battery commander was assigned to each armoured regiment of infantry battalion.
He normally accompanied the regimental or battalion commander.
His troop commanders normally accompanied the two forward squadrons or companies.
It soon 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.
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.
Deployment drills ensured the guns were brought into action as quickly as possible, and without errors that could affect the effectiveness of their fire.
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 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.
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 pre-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.
Imprompu 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.
Pre-planned fire was used in fire plans and could be arranged hours or days before being used.
Fire was programmed (to a time schedule) or on-call.
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 opportunity 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.
Almost all radios were HF, these had greater range than comparable VHF radios, which facilitated large concentrations of fire.
Fire plans using pre-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.
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.
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.
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.
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.
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.
Anti-tank artillery regiments were formed in 1938 by converting regular and Territorial Army artillery field brigades.
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 UK AA Command 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 of LAA and HAA regiments.
Mostly equipped with 40-mm Bofors, including SP, and later some 20-mm Polsten for LAA, 3.7-inch HAA (fixed and mobile mountings) and some 4.5-inch in fixed AA sites.
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
Martime 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.
