Discussion in 'Armour' started by Trux, Aug 29, 2010.

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  1. Trux

    Trux 21 AG Patron


    By 1944 the Royal Armoured Corps had absorbed not only the armoured regiments and
    tank battalions but also reconnaissance units and Phantom. While the armoured regiments
    and tank battalions gradually came to be identical a whole range of specialised armour was
    developed, many requiring the formation of specialist units to deploy them.


    HQ Armoured Brigade. War Establishment II/105/1. November 1943
    HQ Tank Brigade. War Establishment II/142/3. November 1943.
    Armoured Regiment. War Establishment II/151/3. November 1943.
    Armoured Regiment. War Establishment II/157/1. May 1945.

    Tank Regiment. War Establishment II/154/2. November 1943.
    Churchill Crocodile Regiment. War Establishment II/154/2. November 1943.

    Armoured Reconnaissance Regiment. War Establishment II/156/1. November 1943.
    Reconnaissance Regiment. War Establishment II/251/2. December 1943.
    Armoured Car Regiment. War Establishment III/236/2. November 1943.

    HQ Armoured Replacement Group. War Establishment III/317/2.
    Armoured Reinforcement Unit. War Establishment III/318/1
    Army/ Corp Delivery Squadron. War Establishment III/319/1
    Forward Delivery Squadron. War Establishment III/105/1

    GHQ Liaison Regiment. War Establishment III/253/1. August 1943
    GHQ Liaison Regiment. War Establishment XIV/1236/1. July 1944
    GHQ Liaison Regiment. War Establishment XIV/1236/2. September 1944
    Reserve Squadron, GHQ Liaison Regiment. War Establishment III/304/1. January 1944
    Reserve Squadron, GHQ Liaison Regiment. War Establishment III/304/2. March 1945

    Headquarters 30 Armoured Brigade. War Establishment VIII/632/1. January 1944.
    Headquarters, a Flail Brigade. War Establishment XIV/1644/1. January 1945.
    A Regiment of 30 Armoured Brigade. War Establishment VIII/633/1. January 1944.
    A Flail Regiment. War Establishment XIV/164/1. July 1944.
    A Flail Regiment. War Establishment XIV/164/2. January 1945.
    Armoured Personnel Carrier Regiment. War Establishment XIV/1643/1. October 1944.
    Headquarters Tank Brigade (Type B) CDL. War Establishment VIII/450/2. May 1944.
    A Battalion with CDL Tanks. War Establishment VIII/451/2. February 1944.
    A Tank Squadron (Type B) CDL. War Establishment XIV/1645/1. February 1945.

    The Universal Tank.
    Montgomery had formed a clear idea of what armour was to do and a clear idea of what kind of tank he wanted. Armoured units were to be integrated into all arm groups, be able to operate flexibly and perform all the traditional armour tasks. Following on from this he was a proponent of the single ‘Universal’ tank to be used in whatever role was required. The ideal tank would be fast and mobile, have good armour protection and have a gun capable of dealing with any enemy tank. Of course no such tanks existed.

    Of all the British tanks available in 21 Army Group the Comet came nearest to the Universal Tank concept. The Centurian was almost ideal but arrived just too late.


    Tank guns and ammunition.
    Despite efforts to standardise guns and ammunition there was a variety of both in 21 Army Group.

    The design of tank guns was limited by several factors. The first is the length of the barrel. One can achieve a higher velocity by using a longer barrel. However a long barrel is difficult to balance in a turret mounting, is liable to droop under its own weight if too long and light and is liable to collide with obstructions. The second is the size and weight of the propelling charge. The larger the charge, the higher the velocity. However a larger charge will be heavier and longer and thus more difficult to handle in the turret. It will also cause a larger recoil and need a lager turret. Finally the weight of the shell. A heavier shell will have a greater impact but will also be more difficult to handle, and require a heavier charge.

    Anti tank ammunition was generally of the following types.
    - APC. Armour piercing solid shot with a hardened nose cone. The cone was designed to prevent rounds shattering on impact and to cause the round to tilt to 90% on impact in order to achieve greater penetration.
    - APCB. Armour piercing solid shot with a hardened nose cone and a ballistic nose cone to reduce drag and increase velocity. This was the most commonly used round.
    - APDS. Armour piercing discarding sabot. This used a sub calibre tungsten steel solid dart contained in a casing. The casing disintegrated on leaving the muzzle of the gun and the shot continued at high velocity.

    The following tank guns were used.
    This was a gun of 57mm calibre. The version used in 21 Army Group was the Mark V with a barrel length of 43 calibres. Introduced in 1942 it was then an effective anti tank weapon but by 1944 it remained in use only in Churchills Mark III, Mark IV and Mark X. When used with APDS ammunition it remained effective and some Churchill units preferred to keep a proportion of 6pdr armed tanks for anti tank protection. Ammunition included:
    APC. Weight 6lb 5oz. Muzzle velocity 2,900 ft/sec.
    APCBC. Weight 6lb 5oz. Muzzle velocity 2,725 ft/sec.
    APDS. Weight 3lb 2oz. Muzzle velocity 4,000 ft/sec.

    This gun should have had a better performance than the 6pdr which it largely replaced. It used many 6pdr components as possible and was chambered to accept US 75mm ammunition. The anti tank performance was less than that of the 6pdr but it did fire a heavier shell and could fire high explosive rounds. Ammunition included.
    APCBC. Weight 14lb 7oz. Muzzle velocity 2,030 ft/sec.
    HE Weight 14lb 11oz.

    75mm US M3.
    This was the US 75mm as fitted in the Sherman. Performance was much as for the British 75mm.

    Originally developed as a towed anti tank gun the 17pdr was very effective but very heavy and difficult to manhandle. It was mounted in the Sherman Firefly and Challenger tanks, as well as the Archer and Achilles self propelled guns. Ammunition included:
    APCBC. Weight 17lb. Muzzle velocity 2,900 ft/sec.
    APDS. Weight 3lb 14oz. Muzzle velocity 3,950 ft/sec.

    This was a shortened 17pdr to fit into the Comet tank. As a tank gun its advantages over the 17pdr were that it was easier to handle, it was very accurate and the ammunition was shorter and easier to load. Performance was almost as good as the 17pdr since although the cartridge was shorter it was wider. Ammunition included:
    APCBC. Weight 17lb. Muzzle velocity 2,600 ft/sec.
    APDS. Weight 3lb 14oz. Muzzle velocity 3,675 ft/sec.

    95mm Howitzer.
    This was the last of the close support tank guns. It was an effective close support weapon, being able to fire high explosive, smoke and anti tank rounds. The anti tank round was a HEAT (high explosive anti tank) round fired at short range and low velocity. It relied on a shaped charge in which the head of the shell is in the shape of a cone surrounded by high explosive. This focuses a jet of gas which melts the armour. A slug of metal follows and passes through the hole. Ammunition included:
    HE. Weight 25lb.
    HEAT. Weight 14lb 3 oz.

    All British tank ammunition was fixed. This means that the projectile is fixed into the end of the brass case containing the charge.

    Fire Control
    At the beginning of WWII it was British policy that tanks should be able to fire on the move. At that time the standard gun was the 2pounder and this could be aimed and elevated using a shoulder rest. A well trained man could then track a target when on the move. When heavier guns were introduced, together with power traverse and elevating equipment which they needed, this became more difficult.

    The first essential for good fire control was a vision device for each crew member. This was usually a periscope at each crew position, although the gunner might rely on his sighting telescope alone. The commander had a flat cupola with a periscope. Either the periscope or the whole cupola could be rotated to give 360 degree vision. Of course the commander could not see in every direction at once and so relied on all crew members observing.

    The commander would identify a target and aim the turret approximately using a sighting vane. The gunner would then aim accurately using his telescope sight.

    Estimating range was not very sophisticated. Usually the commander guessed the range relying on experience and objects near to the target to give perspective and scale. He had a multi vane sight which gave some idea of the range, which was judged by the amount of the sight the target filled. Allowance had to be made for the size of the target, which depended on accurate identification, and for oblique targets. Observing the fall of shot or following the trajectory by means of a tracer gave an opportunity to correct the range but usually the first shot was the most important. High velocity guns gave a flat trajectory at reasonably short range so did not need so much adjustment for range.

    Traverse was powered on the heavy turrets of later tanks. The British introduced hydraulic traverse which was very smooth and allowed the gunner to traverse the turret rapidly to approximately the correct bearing. It was then possible to traverse smoothly and at a variable rate in order to track a moving target and then traverse very slowly and smoothly for accurate aiming. However hydraulic traverse was expensive to make and, more important, it was difficult to maintain because of dust getting in and oil leaking out. Later tanks such as Churchill VII, Comet and Challenger used electric traverse. Manual control was always available as a back up.

    Elevation for the 6pdr and 75mm was mechanical which made firing on the move impractical. US tanks introduced electrical gun stabilisers which did allow firing on the move. However it was not possible to be accurate enough to ensure a first round hit so that British crews used it to approximately track a target and then stopped to fire.

    Armour protection was also a difficult part of the design equation to get right. Too much armour meant that speed was sacrificed, which was all right for infantry tanks but speed was part of the design philosophy of he cruiser tank. In general tanks had the maximum thickness of armour on the hull front and on the front of the turret. The thinnest armour was on the top surfaces. Opinion was divided on the desirability of having armour underneath. Normally the underside was only vulnerable to mines but in Normandy when tanks went over the hedgerow banks of the bocage they exposed their undersides to anti tank fire.

    Most tanks in 21 Army Group had extra armour fitted. This was usually on the hull front or over places where the ammunition was stored. Most tank fires were started by ammunition catching fire. Later Sherman tanks had wet stowage, which had water tanks surrounding the ammunition. Comet tanks had armoured ammunition bins. Neither were very successful and the Comets armoured bins shattered when hit causing fragments to ricochet round the interior.

    Most tank crews felt that the armour on their tank was inadequate and often went to considerable lengths to improve it. Spare lengths of track were a favourite. These could be old lengths from knocked out tanks, lengths from store or even from different types of tank altogether. They were generally spot welded onto the hull front and onto the turret front and sides. Crews were convinced that the extra thickness and complex shapes gave protection but in many cases they had little effect and may have acted as shell traps, preventing sloped or rounded armour from deflecting rounds. However they had a positive effect on morale.

    Wireless set No 19.
    This applied to all British tanks and most other armoured vehicles.

    Wireless set No19 was a very versatile set and was designed specifically for use in armoured fighting vehicles. The design gave priority to those features that an armoured fighting vehicle needed in action.
    - Reliability. It was robust and relatively easy to maintain.
    - Ease of operation. Two frequencies could be pre selected and in action the frequency could be changed from one to the other by the flick of a single switch. This meant that the operator was not expected to tune the set and change frequencies when moving or when pre occupied with other things. Another great advantage was that tuning the receiver automatically tuned the transmitter, thus making netting fairly simple.
    - Clear speech in battle conditions. This was achieved by using Very High Frequency in the B set.

    An important feature was that the set was in fact three sets in one.
    - A set. A High Frequency transmitter for both voice and Morse. This was for command use down to troop level. Range was 10 miles using voice and 15miles using Morse. Morse was seldom used at squadron levels. The aerial base was Base No8 or Base No10 with an aerial of F rods. These were four foot long and usually two were used to give an 8 foot aerial. Longer aerials were possible but not usual on armoured fighting vehicles. Each squadron would have a net including all troop leaders. Other troop tanks would not need this set but would normally have it tuned to the squadron net in case the troop commander or his tank became a casualty.
    - B set. A Very High Frequency transceiver for voice only. The range on this set was deliberately short, some 1000 yards. This allowed the same frequency to be used by several units along a front, though not usually in the same regiment or even brigade. This used a Base No9 with four foot G rods, slimmer than F rods. Both shorter and longer aerials could be used but were not normally used on fighting tanks.
    - C set. An intercom set for the vehicle crew.

    Each crew position in a tank was provided with a connection point to the intercom and a satchel containing a headset. In action the commander could change from one set to another from his position. Usually troop tanks only used the B and C sets. The C set for talking to the crew and the B set for talking to the troop commander. It was not possible to talk to individual crew members only, so that the commander had to make it clear to whom he was speaking. The radio operator/loader was responsible for keeping the wireless netted, and for keeping a listening watch.

    By 1944 a MkIII set was in use and this gave increased efficiency and lower power consumption as well as a wider frequency range.

    Control tanks could carry a Wireless No19 High Powered which had an amplifier to increase the range considerably. The B set was disconnected in this role as it was used n conjunction with a second No 19 set.

    Daimler Scout Car
    The Daimler Scout Car was a firm favourite throughout the war. It were used with the BEF in France and was still in service in large numbers at the end of the war, and afterwards. It shared most of the advantages of the larger Daimler Armoured Car. The body was of welded armour and the mechanical components were fixed directly to the body shell, there being no conventional chassis.

    The Daimler engine was at the rear and drove all four of the wheels via a five speed gearbox. As on the Daimler Armoured Car the entire box could be put into reverse, giving five reverse gears. Early models had four wheel steering but this was dangerous in untrained hands, and often in trained ones, so was removed on later versions.

    In NW Europe the Daimler Scout Car carried a Wireless set No19 which was on a shelf at the rear of the crew compartment. This made it somewhat difficult to reach. Later cars also had the folding armoured roofs removed, partly in order to safe weight. The weight was made up again by fitting thicker armour to the floor of the vehicle. The car had always suffered from mines, a mine under the front wheels usually killed the crew or at least maimed their legs.

    The Daimler’s low silhouette, good speed and ability to reverse out of trouble made it the preferred vehicle for reconnaissance. Armament was limited to a Bren gun fired through the passenger’s front flap.

    The Humber Scout Car
    The Humber Scout Car was developed because there was always a heavy demand for the Daimler Scout Car that there were not sufficient to go round. It was not such a technically advanced vehicle as the Daimler but it never the less found its own niche and became a popular battlefield run about.

    The first prototype was delivered in 1942 and consisted of an armoured body fitted to the chassis of the Humber FWD which was already in use in several roles, including light reconnaissance car, heavy utility and light ambulance. The engine was moved to the rear. The first contract was for 4,000 cars with deliveries beginning in early 1943. It proved so popular that a second order for 950 was placed, but these were not delivered before the end of the war.

    It was a larger vehicle than the Daimler and it could accommodate three persons. This usually meant a crew of two with space for a third. This made it ideal for transporting officers and others around a battlefield. The Wireless set No19 was fitted down the right hand side of the body so that it was easy for a passenger to operate. This made it useful as a liaison vehicle or wireless rover.

    An interesting feature of the Humber Armoured car was the remote controlled Bren gun mounting on the roof. This was controlled from inside the vehicle so that the gun could be fired without hatches being open and without he crew being exposed. It was also mounted high so that it could fire over hedges etc.

    Access was usually through the roof hatches. There was a sliding roof hatch over the driver and a second sliding hatch on the rear near side. There was a small escape door on the nearside but it was very difficult to use in anything but an emergency.

    Over the winter of 1944/45 many Humber Scout Cars were fitted locally with a variety of windscreens. At the same time however many had the sliding roofs removed to make for easier mounting and dismounting and to reduce weight. Many had canvas covers fitted.

    Stuart Light Tanks.
    The major type of light tank was the US built M3A3, known to the British as Stuart V. These were developed from the earlier M3 series and were all welded and had longer side sponsons which gave more internal stowage. Stuarts were well liked by their crews since they were easy to drive and had relatively good performance. The main armament was only a 37mm gun but reconnaissance vehicles were not generally expected to fight tanks and rarely encountered enemy reconnaissance units. In British service Wireless set No19 was fitted. 174 rounds of 37mm ammunition could be carried.

    For reconnaissance work crews preferred the Stuart Recce which was an official conversion consisting of removing the turret and adding pintle mounted machine guns. Units showed their customary initiative in adding armament and making the vehicles more weatherproof by fitting canvas tilts or covers over the open turret ring. The Stuart Recce was much easier to mount and dismount when near the enemy or under fire. They had a lower silhouette and the lower weight gave an even better performance.

    Some Stuart VI, US M5 and M5A1, were used by the British but these were comparatively rare. This light tank used twin Cadillac engines with an automatic transmission. The hull was higher at the rear but was otherwise similar to the M3A3.

    Chaffee Light Tank
    Late in the campaign small umbers of M24 Light Tank, British Chaffee, were supplied. This tank used the twin Cadillac engines of the M5 but had a completely new hull, suspension and turret. In particular it had a new gun, a light 75mm developed for aircraft use.


    Carrier Starting and Charging.
    Over 2,000 Loyd Carriers were built as Starting and Charging and were issued to armoured units. Tanks were hard on batteries since large tank engines needed considerable power to start them and the tanks often did not do enough running to recharge them. The carrier was equipped with a power take off which drove two dynamos positioned in front of the engine. A 30 volt dynamo was used in conjunction with jump leads to start tanks with flat batteries and a 12 volt dynamo was used to recharge batteries. Switchboards for the dynamos were to the right of the engine. Jump leads were stowed in a tray on top of the engine. Fourteen spare batteries were stowed on each side and on the offside floor. A bottle for battery acid was stowed on top of the dynamo housing. There was a workbench over the batteries on the near side.

    The Carrier Starting and Charging proved to be inadequate for the job. With the fourteen batteries and other equipment the carrier had trouble keeping up with the faster tanks on the road never mind across country. Space for the crew to work in was also limited. They were gradually replaced by 3ton 4 X 4 Machinery I30 lorries.

    Lorry, 3ton 4 X 4 Machinery I30.
    This was originally a REME type to replace the earlier 3ton 6 X 4 Machinery I. Machinery I30 was either an Albion or Fordson WOT6 with a modified GS body. A power take off drove dynamos producing either 15 volts for battery charging or 30 volts for starting. (Earlier I type lorries produced 7½ or 15 volts thus the new vehicle became I30). There were metal covered benched down both sides. Batteries and acid carboys were stowed under both benches and more batteries on top of the offside bench. The nearside bench was a workbench for battery maintenance. Stowage for jump leads was at the rear. This vehicle provided more space for the crew to work, more stowage for batteries, and could keep up with tanks on roads and in all but the most difficult of terrain.
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