BRITISH ARTILLERY - PIECES
ARTILLERY INTELLIGENCE AND COUNTER BATTERY - 1939-1945
Original 19 Jun 2016
|EVOLUTION OF THE CB ORGANISATION||
|Counter Battery Units|
|Malaya & Burma 1942|
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From the artillery intelligence and counter-battery (CB) perspective the Royal Artillery entered World War 2 with much the same equipment as it ended World War 1, albeit in far smaller quantity. Artillery related survey, a Royal Engineers responsibility in World War 1, had become an artillery responsibility in the early 1920s and survey batteries formed, these expanded into regiments in 1938.
Mortars had been ignored by the army in the inter-war period, 3-inch mortars were not issued to British infantry battalions until the late 1930s, and the German army had three times as many in each infantry battalion. One consequence was that little or no attention had been given to the ‘mortar threat’ and locating mortars or to the arrangements for countering them. The equipment of the survey regiments was ill-suited to locating mortars and not very effective in this role. This was to develop into a major problem. Furthermore, in the 1930s both Britain and Russia were developing modern rockets, but no consideration seems to have been given to an enemy’s use of them and the CB issues they would raise. Perhaps this was excusable because UK’s were for AA and Russian work on multi-rocket launchers was almost certainly unknown in the West.
Of greater concern was the RAF’s army cooperation effort, in particular the artillery reconnaissance (Arty/R) role (ie air observed artillery fire). The Lysander had entered service just before WW2 primarily for Arty/R and reconnaissance. Initially there was some use of them in the Arty/R role, but availability was limited and it soon ceased. The effort was well below what the army had been led to expect. No other squadrons were trained in the role.
Sound ranging and flash-spotting had continued to exist throughout the inter-war period, and their equipment had been somewhat updated. However, little consideration had been given to counter-mortar methods and the effectiveness of sound ranging and flash-spotting against mortars.
EVOLUTION OF THE CB ORGANISATION
At the outbreak of war the Counter-Battery Officer (CBO) and staff were part of the Commander Corps Medium Artillery (CCMA)’s staff. The CBO staff comprised a Lieutenant Colonel, Captain and Lieutenant with two clerks and a draughtsman. This small staff was also supposed to be able to be decentralised to divisions and to operate day and night! It was recognised that during prolonged fighting additional staff would be required. Their duties covered all aspects of CB intelligence processing and recordkeeping, planning and controlling CB fire, CB policy matters, preparing the enemy artillery assessment as part of the General Staff planning process and arrangements for air photography including interpretation.
The position and staff of CCMA were removed when Army Groups RA (AGRA)s were created in 1942. The CBO staff became a separate organisation and the corps artillery commander (CCRA) could decide how to deploy them. The usual practice was for them to report to the commander of the AGRA assigned to the corps.
At the end of 1943 there was a re-organisation. The CBO became a major but the CBO staff substantially increased in size. In addition to the core corps CB staff it included three detachable sections. Two sections were designed to be attached to divisional HQs if required, eg during offensive operations. The third section joined the corps’ Army Photographic Intelligence Section (APIS) usually co-located with an RAF reconnaissance wing to ensure rapid access to air photos. The APIS included RE surveyors who produced target coordinates from vertical air photos using the block plot method. In addition to the normal vertical airphotos, oblique air photos were used to detect targets under cover.
The pre-war regular army survey company (with sound ranging, flash-spotting and survey functional elements) had expanded to a regiment (1 Survey Regiment) in the spring of 1939, with a battery for each of the three functions. The sound ranging and flash-spotting batteries each comprised two troops. Each troop provided either a sound ranging or flash-spotting base.
The survey battery had two survey sections, they provided artillery survey (ie fixation and orientation) for all the field artillery regiments assigned to a corps. This was a critical artillery task because the 1938 reorganisation had removed survey sections from the field and medium artillery regiments. The justification for this was that there would be no role for regimental sections in mobile warfare.
The survey sections in Survey Regiments were also responsible for ‘airburst ranging’, the use of high airburst HE shells cross-observed by surveyors, a technique developed in WW1. It was used to range targets with accurately known positions (eg from air photos) but out of sight to ground observers. However, mechanical time airburst fuzes (used with HE) had not been developed for the new generation of field artillery such as 25-pr. Rectification of this started in 1940 in response to Canadian demands, but fuzes did not become available until 1943.
A few weeks before the outbreak of war a second regular survey regiment was raised with its nucleus from the first. Two Territorial Army survey companies had been formed in the 1930s, in 1938 they expanded to regiments and at the end of the year each ‘spawned’ a second regiment. At the outbreak of war there were six survey regiments, albeit with a fairly thin spread of expertise.
However, in the summer of 1940, after Dunkirk, a notably under-informed War Office committee decided that there was no need for any survey because there was no requirement for it in mobile war. Mapping would be handled by the Ordnance Survey and that was it. It was decided, with minimal artillery input, that RA survey regiments should be disbanded. This decision was rapidly rescinded and in August the regimental organisation of three specialist batteries was ‘tweaked’ and approved but no major changes were made. Nevertheless, 6 Survey Regiment was disbanded in late 1940 but sent a survey troop with 4 Survey Regt to the Middle East. Early in 1941 three new survey regiments were formed.
The Air Ministry’s obligation to provide meteorological detachments producing meteor data for artillery was not implemented until units went overseas. These detachments were normally an officer and four men, but in late 1941 the officer position was replaced by a flight sergeant.
The problem was that their key activity, using a meteor theodolite to track a pilot balloon in order to determine wind speed and direction, was limited by the cloudbase, above this upper air forecasting had to be used. This meant that in theatres where cloud was a regular occurrence data accuracy was sub-optimal. Hence meteorological data for predicted fire at the longer ranges required for CB was less accurate and in consequence fire was less accurate. However, the sound ranging requirement for meteorological data did not extend more than a few hundred feet above ground level and this was well within the meteorological capabilities in almost all conditions.
Early in 1942 after a year of experience in N Africa the survey regiment organisation was formally changed from three specialist batteries into two composite batteries with troops for survey, sound ranging and flash spotting. There was an additional survey section in regimental HQ with particular responsibilities for airburst ranging once appropriate airburst fuzes were available, although the other survey sections also undertook this task. By this time regimental survey sections had been re-established in field, etc, regiments, which meant that the survey regiment needed only to deliver survey control data to each regiment instead of to each battery. This survey control data was a ‘peg’ in the ground with a Bearing Picket (BP) card giving its coordinates and accurate bearings to visible reference objects.
There were no dedicated CB regiments or batteries. However, it was generally considered that at least medium artillery was required for effective CB fire.
The BEF went to France in 1939 and was steadily strengthened as mobilisation and the creation of new units continued. The normal scale of field artillery above divisional level was two medium regiments and two army field regiments that, with the corps’ survey regiment were under command of the CCMA in each corps. Additional army field and medium regiments, together with heavy and super heavy artillery, were commanded by the Major General RA (MGRA) at GHQ and could be allocated to lower level formations. As the war progressed some army field regiments were converted to medium regiments.
Throughout the war medium regiments had 16 guns organised into two batteries. Initially these were WW1 60-pdr Gun and 6-in Howitzer, albeit with pneumatic tyres, vehicle towing and calibrating sights. The new 4.5-in Gun (max range 20,500 yards), initially on a 60-pdr carriage, reached N Africa in mid 1941. By mid-1942 it was joined by the new 5.5-in Gun (max range 16,000/18,100 yards depending on shell) on a new carriage, and the same new carriage was provided for 4.5-in. Most regiments were equipped with one or the other although a few had a battery of each. The longer range of the 4.5-inch Gun meant it was favoured for CB. After the losses at Dunkirk some 155mm Howitzers Howitzer M1917 were provided by the US under Lend Lease. A few were used in N Africa in 1941 by 2/1 Australian Medium Regiment. From a CB perspective their maximum range of 12,400 yards offered a little more than a 6-in Howitzer, maximum range of 9,800 or 11,400 depending on shell weight. 5.5-in gave 16,200 yards with its 100lb shell and 18,100 yards with its 80 lb shell (introduced in 1944).
Heavy regiments were also available for CB, however, their batteries only had 4 guns each. 7.2 inch gave 16,900 yards maximum range, although the long barrel version on the M1 carriage introduced late in the war gave 19,600 yards. US 155mm guns were also used in these regiments, max range 23,395 yards.
For comparison, the German artillery was:
10.5 cm light field howitzer 18 –
max rg 11,675 yards
10.5 cm light field howitzer 18M – max rg 13,479 yards
10 cm gun 18 – max range 20,860 yards
15 cm heavy field howitzer – max range14,490 yards
17 cm gun 18 – max range 32,371 yards
In September 1942 AGRAs started forming in UK. These centralised all medium and heavy regiments under army level command and were assigned to corps as necessary, usually one AGRA per corps. The CCMA position was abolished.
The usual AGRA organisation was an HQ (brigadier commanding, the ‘CAGRA’), with 4 medium regiments, a field regiment and a heavy regiment, but there was some variation. In addition the AGRA had its own RASC transport company to supply ammunition and a signals section. The CAGRA was usually responsible for the corps CB battle on behalf of the CCRA. The corps CB staff remained part of corps HQ, but in some corps elements usually joined the CAGRA’s HQ.
A development by the BBC in early 1942 also proved useful, the introduction of broadcast time-signals. This greatly simplified time synchronisation across many batteries and facilitated Time on Target (ToT) attacks, where batteries fired at ToT less their shell time of flight.
A new sound recorder (Recorder, Sound Ranging No 1, Mk 1) had been developed in the 1930s to replace the WW1 equipment. It still used photographic film with integrated film-processing arrangements. This device was quite large, albeit smaller than the WW1 item, and was fitted in a special purpose vehicle. This equipment recorded the signals from the microphones on to photographic film that was immediately and automatically processed by the equipment. Recording and processing were in light-proof containers.
Obviously such a device was not run continuously. Each microphone base had two manned ‘Advance Posts’ (AP), typically about two thousand yards in front of the base. These APs had remote control of the recorder and switched it on when a hostile battery was heard firing. Their distance in front of the base ensured that this happened before the sound wave reached the microphone nearest to the enemy battery that fired.
However, the experience in France in 1940 had made clear that line communications were less than satisfactory and that radio was required for both Flash Spotting and Sound Ranging. This had been identified pre-war but only limited progress had been made in providing it. Radio link was introduced for sound ranging in 1940, although it wasn’t notably effective, but by 1942 it had improved. It used a No 11 (SR) wireless at each microphone, each wireless had its own frequency and communicated to its R105 receiver at the sound ranging command post. The final step was to convert the radio or line sound wave from each microphone into a narrow pencil beam of light that was projected onto moving film.
The SR wireless sets had a different frequency band to standard No 11. This set-up could handle a base of up to five microphones and bases could use a mix of wireless and line (D 8 twisted pair) communications. The microphones, were still the hot-wire type, developed in WW1.
The processed film was manually analysed to determine the sound arrival time differences at each microphone and bearings produced from the mid-point between each microphone pair. There were several methods for this ('circle', 'graph', 'secant' and 'asymptote') using graphs or plotting boards, but the asymptote method gradually emerged as the preferred one.
With a regular base (ie equidistant microphones in a straight line) an Asymptote Plotter, SR, No 1 Mk 1 was used, it was constructed at 1:25,000 map scale and could be used with a map. Irregular bases meant setting up a Board Plotting, SR, using printed celluloid time scales. The bearing plotting process didn't use paper and pencil methods but fine strings attached to a pin at centre point between a microphone pair. There was a lead weight at loose end of each string. Using the bearing arc for each microphone pair, the bearing deduced from the sound times of arrival for each pair could be quickly laid out on the plotting board to give a ‘cats-cradle’ at the HB location. In the early 1930s a mechanical plotter had been developed but this doesn't seem to have entered service (it gets no mention in the 1938 Sound Ranging Manual) - the guru of sound ranging, Professor Sir Lawrence Bragg, always advised simplicity and the mechanical plotter was not simple.
Being permanently mounted in vehicles meant that most of the Mk 1 recorders were lost in France in 1940. An improved version of Sound Ranging Recording Equipment No 1 Mk 1 that was more compact and easier to manufacture had been attempted in the late 1930s but it was unreliable and did not enter service. However, later in 1940 the Mk 2 was introduced. A serving officer (Capt Gordon Scarrott (1916-96), and post-war a leading computer engineer) identified improvements that became the Mk 3 and by the end of 1943 the further improved Mk 4 entered service.
Teledetos paper was introduced in 1943. This carbon backed paper was directly marked by the metal pens of the new SR recorder, SR No 2 Mk 1. It eliminated the need for film processing and consequently speeded up and simplified the process.
Scarrott and another officer also investigated microphone performance. They found that a linear mike with a steady background air current of 4 cm/sec increased sensitivity to accurately detect the air current oscillations created by the sound pressure wave of guns firing. This also created a more compact microphone.
The other item of sound ranging equipment was the comparator, a special purpose mechanical analogue computer. This was used to compare the sound source of an HB location with the sound of counter-battery shell bursts fired at it and deduce a correction. The Mk 1 had been introduced in the late 1930s, Scarrott and another officer developed an improved Mk 2. In late 1942 the Mk 4 was introduced, and this was the final model.
There was one final matter for sound ranging, the microphones were susceptible to wind noise. Microphones were normally placed in shallow holes but this was insufficient, covers for the holes were introduced. Initially there were various shapes (one was several feet high!) for the covers but a single design was soon emerged, it was about one in yard diameter and 6 inches high and covered the small hole in which the microphone was placed. These covers comprised a metal frame covered in woven coir matting.
Flash spotting was more dependent on operator skill than sound ranging because observations were made by individuals, not automatically recorded. The key element was ensuring that three or more observers were all looking at the same flash. This was not simple when several hostile batteries were firing at the same time. The critical factor was the field of view of the instruments used, none greater than 5° 40’, giving visibility of an area of about 600 yards wide at a distance of 5000 yards (and 1200 yards at 10,000 yards, etc).
Each troop had four flash spotting posts, and observations from at least three were required to reliably and accurately ‘fix’ a hostile battery. The distance between posts seems to have varied from about 2000 to 8000 yards. All the posts in a flash spotting ‘base’ had to be accurately surveyed and oriented to the map grid. Depending on the availability of survey control points this could take some time using conventional survey traverse methods, and speed into action was important. The challenges were exacerbated by posts being in forward areas in positions with a good view of the enemy, with the implication that the enemy could have a view of them if they were not well concealed, this need for concealment complicated the survey task.
However, different survey methods were used for flash-spotting. A control instrument at the survey troop plotting centre was oriented by astronomical observation – such as azimuth by polaris at night, and azimuth by hour angle or by altitude during the day, (observing the sun). From these observations and data in astronomical tables and on maps the direction of grid north could be accurately calculated. To avoid every post doing this the short-cut was simultaneous observation by the control instrument and the instruments at each flash spotting post. This enabled the latter to be accurately oriented. If the post wasn’t facing a suitable direction then orientation was to another instrument nearby and transferred to the post by normal survey methods. Each post then selected three features whose locations were accurately known and grid bearings measured to them, plotted on a chart and the post’s position accurately determined.
The primary observing instrument at each post was an Instrument Flash Spotting No 4 with a 5° 40’ field of view and a Long View Telescope, a WW 1 device with a field of view from 2° 30’ to 1° 15’ depending on selected magnification. The No 4 instrument had been introduced during the inter-war period and although new Marks appeared there were no major changes to it. It could be mounted on a field tripod or a ‘table-top’ mount, the latter being used on a table or window-sill in a house or shelf in a trench.
The problem was getting at least three OPs all observing the same flash. In WW1 a ‘flash and buzzer’ device was used to synchronise the posts’ observations to ensure they were all observing the same flash. This device was used in the early part of WW2. However by 1941 they were replaced by observation procedures, whereby one post coordinated observations by verbally reporting each flash as it occurred, enabling other posts to observe the same flash. Once at least three OPs were observing the same flash, then they could report their observed bearings to the plotting centre.
In 1941 there was a significant change to flash spotting, the introduction of 'short base flash spotting' and reorganisation of the flash spotting troop observers into three squads, each of 13 men commanded by a serjeant.
Each squad could reconnoitre, deploy and operate a short base comprising two observation posts (called ‘main’ and ‘sub-post’) between 180 and 400 yards apart. It was used in terrain where it was difficult to get bearings of the same flash from several widely separated posts, it was also much faster to establish a base, and reduced the amount of cable laying if speed into action was critical. Obviously a short base was not as accurate as a long one, but this could be minimised by ensuring great accuracy in measuring the relatively short distance between the instruments in the two posts. The short bases could be converted to a long base of three posts by each of the three squads in a troop manning a single observation post.
The bearings of observed flashes were reported to the troop’s flash-spotting plotting centre where they were plotted and hostile battery positions determined. In addition to the usual tactical and intelligence maps, the flash-spotting plotting centre used two boards specifically for flash spotting:
· The concentration board was marked with a grid representing the map grid with gridlines numbered for the area. On it were marked:
o Each FS observation post (OP).
o A bearing arc for each OP.
o Tactical information as required, such as known and suspect HBs, important topographical features and the line of forward troops.
The bearing reported by each OP was marked on the board, and their intersection gave the HB location plot.
· The quadrant board was gridded and numbered identically to the concentration board. It was marked with two 90° arcs and their circle centres. These arcs and centres were used to align a rolling parallel ruler on the bearing for each OP, the ruler was then rolled to the actual OP position and a line drawn in the appropriate area on the map. This was repeated for each OP and the intersection was an accurate HB location plot.
A Flash Spotting tower was used at Tobruk, and although short-lived led to such towers becoming a standard item, held outside survey regiments but available when needed if the front was static. Their use seems to have been infrequent.
The North African campaign highlighted the increasing German use of mortars, with ranges up to 4000 yards – the British 3-inch mortar was limited to 1600 yards at this time, although the 4.2-inch mortar that entered service in 1942 had a range of 4100 yards but was not widely used. Initially the 4.2-inch only equipped RE chemical warfare companies to fire smoke, but subsequently replaced the machine guns in one company of the divisional machine gun battalion.
Sound Ranging bases were generally deployed too far back to locate the German mortars, but could get results if the base was deployed further forward. However, in late 1943 development of a new 4-pen sound ranging recorder started, specifically designed for mortar locating, in early 1944 it was changed to use Teledetos paper with electromechanical scribers. It was sent to Italy for trials in mid 1944 and proved successful, following this four were issued to each Survey Regiment.
It was estimated 70% of UK casualties in Normandy were from mortars. In June 1944 the 4-pen pen recorder was still under development but prototypes reached Normandy in early July and proved successful in I & XXX Corps. Thirteen counter-mortar batteries were then formed to use the new equipment, three for NW Europe, five for Italy and five for South East Asia. The latter were not entirely necessary because the Japanese mortar threat was nowhere near the level of the German one, and the batteries remained in India.
By spring 1945 a tropicalised version of the 4- pen recorder was produced together with a 7- pen recorder and a new device called CODAR. This used clusters of 4 microphones each a few feet apart in a square pattern, a cathode ray tube displayed the bearing from the cluster to sound, and this was reported to the plotting centre, none of these entered service in WW2. However, the 7-pen recorder led to the post-war equipment, and the cluster method, with an unattended PC in each cluster for calculations, entered service in the 1990s.
Combining CB and CM organisations proved unsuccessful in Italy, an entirely different deployment was required because CM needed to be decentralised with a CMO for each division (normally attached to HQRA) and an ACMO with each brigade. Locating methods included MOREPs (reports from all-arms of enemy mortars firing). These reports included a compass bearing to the firing sound. Other sources of information were Air OPs seeing mortars, Flash Spotting and sound ranging with 4-pen recorders. When extra manpower was required it had to be found from within the divisional artillery and trained by the Corps CBOs.
CM staff were also given responsibility for infantry guns and nebelwerfers (MRLs) because these were short range. Typically German 8.1 cm mortars were about 500-800 metres behind the most forward troops, 12.1 cm mortars about 1000 metres and nebelwerfers about 4000 metres.
Trials with GLIII radar against mortars had been unsuccessful early in 1943, but were revived later that year then stalled as being ‘too defensive’. GLIII was not greatly effective, it needed observations of several bombs. However, Radar AA No 3 Mk 5 with autotrack gave quick locations to 25 yards accuracy on 1 or 2 bombs.
8.1 cm mortars were difficult targets for these radars, but larger calibres were easy to track. In November 1944 21 Army Group found locating accuracy was 50 yards for Radar GLIII, 100 yards for 4-pen recorders and 150-200 yards for listening posts, in the latter case partly because these posts were not accurately surveyed. They also found that MOREPS (verbal reports of mortars firing) sometimes confused different mortars. For both 4-pen bases and radars it took about a day to move and become effective in a new position.
For counter-mortar fire known mortar positions were grouped for bombards. Upper register fire for counter-mortar fire had been tried in 1943, but was found to be of limited use. Mechanical Time (MT) airburst fuzes were effective, but inaccuracies made use against targets close to own troops inadvisable. The preferred guns for CM fire were 3.7 in HAA (due to their MT fuzes), 7.2-inch Howitzers and medium (4.5 and 5.5-in) guns.
THE EARLY CAMPAIGNS
The British Expeditionary Force 1939-40
At the outbreak of war HQs I and II Corps were formed from HQs Aldershot and Southern Command together with their HQRAs, including CBOs with their staffs, and the CCMAs with their staffs. The two corps artilleries included 1 and 2 Survey Regiments. They were followed by III Corps and 3 Survey Regiment in the spring of 1940. The RAF meteorological detachments joined the regiments in France.
When German forces advanced through Belgium and France the pace of their advance gave only limited opportunity to deploy sound ranging and flash spotting bases. Insufficient wireless was held and the speed of the German advance meant it was mostly impossible to recover cable, leading to shortages. Furthermore the scale of hostile battery activity made it difficult to produce accurate HB locations. Nevertheless, there appear to have been some counter-battery engagements. Normal field artillery observers also had some success against infantry guns and mortars.
The RAF Lysanders were unable to operate in the hostile environment dominated by high performance fighters. Two thirds of them were lost to enemy action, but it is unclear what tasks they were undertaking because ‘army cooperation’ also included offensive action against ground targets and Lysanders were able to drop small bombs.
The extent of tactical reconnaissance (Tac/R), notably photo-reconnaissance, is also unclear. However, in a mobile battle the ability to deliver promptly photographs to the army HQ that sought them may also have been problematic, as the early desert campaigns showed.
One lesson from the campaign was the effective German use of mortars. This led to a significant increase in the size of British mortar platoons. However, it does not seem to have led to much activity related to detecting enemy mortars, possibly because there had been so little use of sound ranging and flash spotting that they were assumed to be adequate against mortars.
Most survey batteries managed to return to UK with at least some of their instruments. However, all the sound ranging recording equipment, mounted in specially fitted trucks, was lost. IV Corps mobilised with its survey regiment but did not leave UK before the German offensive in 1940.
After Dunkirk a survey battery operated on the South coast of England around Dover, opposite the German fixed coast batteries. The cross-channel distance was such that a normal sound ranging base would have been ineffective. However, in WW1 it had been found that long range guns could be located by using bearings produced by two or more bases, this technique may have been used at Dover. Given air photography it is also likely that the main effort was to identify the actual batteries from dummy batteries. It appears that there was some CB fire from Dover by the Royal Marine Artillery’s 14-inch guns, but this was ineffective.
In late 1940 4 Survey Regiment left IV Corps and departed for the Middle East, arriving at the end of December. For the next two years it was the only UK survey regiment deployed overseas.
The first detachments from 4 Survey Regiment were SR and survey troops to East Africa and the defeat of the Italian army in Eritrea. The survey troop took on the flash spotting role. Italian batteries were located by sound ranging and eventually by flash spotting (the Italians did not generally fire at night). However, meteor conditions were very unstable and data were poor, this made map shooting generally impractical. Nevertheless, the total number of HB locations was more than in the campaign in France in 1940.
However, CB also needs appropriate medium and heavy guns to attack the located artillery. Until well into 1942 the available medium artillery was old and lacked range, which significantly limited its usefulness for CB. At the outbreak of war there was a single medium regiment (7th), with one battery of 60-pdr guns and one of 6-in howitzers, in the Middle East. Two more regiments arrived in late 1940, and two more later still, plus one with the Australian corps. These regiments were spread thinly in the theatre. Furthermore they we equipped with 60-pr
4 Survey Regiment deployed to Greece in 1941 under command of the Australian Corps HQ. There was some deployment but no HBs were located. After less than four weeks the regiment was among the first to be evacuated from Greece to Crete and then back to Egypt. They managed to evacuate most of their instruments and technical stores.
However, in his final report on handing over to General Auchinleck in mid-1941, General Wavell reported that for all practical purposes the established forms of Army cooperation by the Air Force - artillery observation and close tactical reconnaissance - had ceased. The aircraft designed for the role (primarily Lysander) could not be flown in the presence of the enemy and the supply of pilots trained in army co-operation was exhausted. Furthermore the photo-reconnaissance resources had never been sufficient to meet the army’s needs.
The NZ Survey battery arrived in the Middle East in late 1940, initially it undertook topographic survey mostly in Palestine. In April 1941 it went to Greece in its artillery survey role. At the end of 1942 it joined 2 NZ Division as a composite battery with survey, flash-spotting and sound ranging troops.
2/1 Australian Survey Regiment arrived in the Middle East in May 1941 and 2/1 Medium Regiment four months later. In July the Survey Regiment had survey, flash-spotting and sound ranging troops in an ad-hoc composite battery in action in Syria reporting to an ad-hoc divisional CB staff. Air reconnaissance made no CB contribution. The medium regiment was equipped with World War 1 French 155mm Guns produced in the US for the US Army and provided to UK under lend-lease arrangements. The extent of similarly equipped British medium regiments is unclear.
By mid 1941 it was becoming increasingly clear that the survey regiment organisation of three specialist batteries was not what was needed. In June a composite battery was formed comprising flash-spotting and sound ranging troops, this battery went to Tobruk. There were still equipment shortages and for flash-spotting standard theodolites had to supplement the flash-spotting instruments. The basic trade in the survey regiment was surveyor, so the lack of a specialist survey troop was not a major drawback in Tobruk. The survey troops were needed to help the Royal Engineer (RE) surveyors make good the survey deficiencies throughout the Middle East. The problems included maps with different geodetic datums depending on who had undertaken the original survey, eg Italian in Libya. Tobruk also saw the use, albeit brief, of an observation tower for flash-spotters. A standard design for such towers, meaning the RE knew exactly what material and stores were required for construction, had been developed just before the outbreak of war.
1 Australian Corps had a CBO and this officer was the CBO in Tobruk. The artillery in Tobruk included four British field regiments, mostly with assorted guns. However, the CB battle was mostly undertaken by an Australian field regiment with 60-pdrs and 4.5-in Hows. The degree of success is unclear. It is unlikely that the available CB resources could achieve a useful amount of destruction, and neutralisation, if effective, would only temporarily neutralise hostile batteries. Since neutralisation was only effective while CB fire was falling, the small artillery force meant such fire was limited.
In January 1942 the perceived Japanese threat to Australia meant that the Australian survey and the medium regiments were ordered to return to Australia with most of the Australian corps, no survey element was left with the remaining Australian division.
The expansion of the Western Desert Force into 8th Army with two, and eventually three corps brought no additional survey elements, in fact the withdrawal of 2/1 Australian Survey Regiment at the end of 1941 almost halved the theatre’s organic CB target acquisition capabilities. However, air photographic coverage was good and well suited to finding HB positions during static phases of the war, although air photography did not necessarily reveal if ‘batteries’ were real or dummy. Furthermore, it appears that all corps had CB staffs and there was a CBO at HQ 8th Army. What was lacking was anything like the necessary number of medium regiments to deliver adequate CB fire. Having the CB staffs but lacking the means to conduct the CB battle was a far from ideal situation.
The problem with air photography was the time it took to get photos from the airfields to the CB staff. For example even in September 1942, only weeks before El Alamein, it was taking 36 hours to receive air photos from the RAF. To solve this RE Surveyors and a RA CB section were moved to the RAF Reconnaissance Wing HQ. This enabled prompt photo interpretation, CB analysis and accurate calculation of HB coordinates from air photos. The results being communicated to the CB staff at formation HQs. By the end of the Alamein battle results were being received within 4 or 5 hours of the aircraft landing.
Air photos were the primary means of accurately locating hostile batteries, flash-spotting and sound ranging were used determine which batteries were active. Before the Alamein battle started there were some destruction shoots against a few active HBs and neutralisation against roving guns. Nevertheless all HBs were silenced by the start of the infantry assault but as the attack progressed HBs moved to new positions so CB intelligence was never fully up to date and allied casualties increased.
The CB battle was fought by XXX Corps with the three available medium regiments (as an ad hoc medium artillery group) and up to 4 field regiments. This CB group was commanded by the CO of one of the medium regiments because by this time the CCMA position had been removed but no AGRAs had been formed or arrived in N Africa. The normal method of engagement was the Bombard. The three medium regiments had six batteries and there was a small Free French battery, in all totalling 32 x 4.5 and 20 x 5.5-inch guns, the latter using 100 lb shells giving a maximum range of 16,000 yards. Of course the new scale of AGRAs meant that there should have been one for each of the three corps at El Alamein, at least 24 medium batteries (192 guns)! Nevertheless the one significant enhancement was the addition of 3 Survey Regiment to 8th Army.
Malaya and Burma 1942
The counter-battery action in these campaigns was effectively non-existent. There was no artillery survey support, no medium artillery and there does not appear to have been any CB staff. The extent of ad hoc CB action, if any, is unclear.
THE SECOND HALF OF THE WAR
The British 1st Army that landed in Algeria in early November 1942 was on a reasonable footing for CB. Both V and IX Corps had survey regiments (5 and 8) and CB staffs and the corps level field artillery for the two corps totalled 2 heavy, 4 medium and 4 field regiments. The Army also had the first Air OP squadron with its artillery officer pilots, these would prove useful for CB in the conditions of the theatre.
Two weeks after the invasion AGRAs were formally established, significantly increasing the scale corps level artillery. However, there was no immediate increase in regiments to provide the new scale of artillery.
In the final stages of the campaign there was renewed interest in Arty/R. Two of the Desert Airforce’s reconnaissance squadrons (40 (SAAF) and 225 Sqns) underwent special training and air communications radios were issued to some artillery regiments. Unfortunately the radios were somewhat unreliable and the pilots were limited to reporting HB locations. However, 40 Sqn acquired an interest in Arty/R and developed their skills in preparation for moving to Europe.
Enemy mortars were again a problem, but there was still no significant activity in developing effective counter-measures. The broken terrain of Tunisia was well suited to their use, not least for concealment reasons. Nebelwerfer multi-rocket launchers also appeared in the final months of the campaign in N Africa.
The invasion of Sicily involved the newly arrived 3 Survey Regiment after the invasion 8th Army’s 4 Survey Regiment, returned to UK with XXX Corps for the invasion of NW Europe. 3, 5, and 8 Survey Regiments then moved into Italy as part of 8th Army, not forgetting 1 Canadian Survey Regiment with the I Canadian Corps and 1 Polish Artillery Survey Regiment with II Polish Corps.
For the invasion of Europe in June 1944 the CB organisation was fully formed. Corps had their CB staffs, AGRAs were available, and every corps had its survey regiment. Techniques and procedures were also well established. The problem, as previously explained, was the mortar threat.
The Japanese had a very large variety of artillery (guns and howitzers), some in larger quantity, others relatively few. Some were quite modern while others dated to before WW1. The extent of ammunition commonality between guns of the same calibre is unclear. It is also unclear exactly which types were deployed in Burma. Most guns were 75 mm, but there were also some 10 and 15 cm. In addition there were anti-tank guns, infantry guns and mortars.
The basic and most widely used Japanese field gun was 75 mm of one type or another, mostly firing a shell of 12 – 14 lbs to a maximum range of around 12,000 yards. However, being guns they were limited to a maximum elevation of 45 degrees. There were, however, various 10 and 15 cm Howitzers, but there were only small numbers of these in Burma, and not all types of howitzer were capable of upper register (ie > 45 degs) firing.
The Japanese army had three artillery intelligence regiments with sound ranging, flash spotting, air photo reading and related capabilities. However, it does not appear that any elements of them served in Burma.
UK eventually had three survey regiments in Burma (1, 2 and 1 (Indian)), each supporting a corps. However, there were no AGRAs in Burma, although they were forming in India when the war ended. This meant that CB fire was delivered by the divisional field regiments and a corps’ single medium regiment.
It should also be noted that 14th Army’s front along the India-Burma border was two or three times the length of the 8th Army’s front in Italy, which in turn was two or three times the width of 21st Army Group’s front in France. The Japanese troop density was also low. Three survey regiments were nowhere near enough to provide full coverage. A technical complication was the longer time needed to undertake survey in jungle conditions due to reduced visibility. Obviously once the breakout occurred into the Irrawaddy Valley conditions became easier from a survey perspective, although the speed of the advance created its own challenges. These factors meant that the number of HB locations in Burma was far below that in western theatres.
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