The M32 tank recovery vehicle was the only Sherman engineer tank
variant to be produced in volume. Changes from the standard gun tank
specification included the addition of a large, fixed superstructure in
place of the turret, and an 81mm smoke-laying mortar fitted to the top
of the hull. There was a 60,000lb winch in the fighting compartment, and
a pivoting A-frame jib on the hull. The photograph shows the M32B1
variant using the cast M4A1 chassis.
The British-designed Sherman ARV Mk II incorporated a Croft 60-ton
winch in the fighting compartment, a detachable 3.5-ton winch at the
front and a fixed 9.5-ton winch at the rear. There was also a
substantial earth anchor and a fixed ‘turret’ in which was installed a
dummy gun.
The most effective Sherman-based anti-mine device was the chain flail, consisting of a large cylinder carried ahead of the tank to which were attached a series of chains. In this photograph the side covers of the flail have been removed to show the chain drive.
The flame-thrower is a very effective weapon against entrenched
infantry. This Sherman M4A3E8, photographed in Korea, has been equipped
with a flame projector – possibly the US Marine Corps POA-CWS 75 H1
device – operating through the barrel of the main gun.
The origins of what are generally called ‘engineers’ tanks’ date back
to the earliest days of tank warfare, when in 1917 the British Army
modified a number of their Mk IV heavy tanks to facilitate the crossing
of deep ditches or trenches. The tanks were adapted to carry fascine
bundles or hollow timber cylinders that could be dropped into the ditch
in such a way that the tank could drive across it. Mk IV and Mk V tanks
were also equipped as bridging tanks by being fitted with hinged ramps
to provide a means of crossing other obstacles. Others had their
armaments removed and were adapted for use as supply vehicles or gun
carriers, while the armoured recovery vehicle was developed by the
simple expedient of attaching a jib and pulley block, or a powered
crane, to the front of an older or obsolete tank. After the Armistice
was signed in 1918 development of the machines generally came to a halt,
with few special tanks produced during the interwar years. The outbreak
of the Second World War brought a resurgence of interest in using what
were essentially modified tanks for specialised roles, particularly for
recovering disabled armoured vehicles, a task that was often beyond the
capabilities of existing wheeled heavy tractors.
Engineers’ tanks really came into their own during the D-Day
landings. In the months preceding the invasion a range of so-called
‘funnies’ was developed, each tasked with overcoming a particular
problem, and these vehicles made an enormous contribution to the success
of the landings. The fact that the Sherman was plentiful, simple in
construction and above all reliable made it the ideal choice for
producing a whole range of these specialised vehicles, for example flail
tanks, mine-clearing devices, rocket-launchers and flame-throwers. Most
of the conversions were ‘official’, but others, including the mounting
of a double-track assault bridge on the Sherman nose, were field
modifications made in response to the changing situation on the ground …
and the US authorities did not necessarily always agree with what the
British were doing to ‘their’ tanks.
The US Army’s M32 tank recovery vehicle was the only Sherman engineer
tank variant to be produced in significant volume, and the pilot model,
built by Lima Locomotive in 1943, was constructed on the hull of a
standard M4 from which the gun and turret had been removed. It was
originally designated TRV (tank recovery vehicle) T5, and changes from
the standard gun tank specification included the addition of a large,
fixed superstructure mounted in place of the turret, and an 81mm
smoke-laying mortar fitted to the top of the hull. A 60,000lb winch was
installed in the fighting compartment, and there was a pivoting A-frame
jib on the hull, mounted in such a way that it could be used in
conjunction with the winch. Additional tow points and equipment stowage
facilities were also provided. The design was standardised as the M32 in
September 1943. Later variants included the M32B1, based on the hull of
the M4A1; the M32B2, which used the M4A2 hull; the M32B3, using the
hull of the M4A3, including some examples with HVSS suspension; and the
M32B4, which used the M4A4 hull, but never made it into production. As
well as Lima Locomotive, M32 recovery vehicles were constructed by the
Baldwin Locomotive Works, Federal Machine & Welder, International
Harvester and Pressed Steel Car.
Entering service in 1944, the M32B1 was also converted into a prime
mover for heavy artillery by the removal of the A-frame; in this form it
was designated ‘full track prime mover M34’.
The British Army also used the M32 recovery vehicle, describing it as
the ‘armoured recovery vehicle (ARV) Mk III’, but the workshops of the
Royal Electrical and Mechanical Engineers (REME) also constructed a
‘British’ Sherman-based recovery vehicle that they designated ‘ARV Mk
II’. The vehicle incorporated three winches – a Croft 60-ton winch
installed in the fighting compartment, a detachable 3.5-ton winch at the
front, and a fixed 9.5-ton winch at the rear; there was also a
substantial earth anchor designed to hold the vehicle in place during
heavy ‘pulls’. In order to camouflage the significance of the vehicle,
there was also a fixed ‘turret’ in which was installed a dummy gun.
REME also developed a more specialised vehicle for recovering drowned
or disabled tanks, or other vehicles, from the D-Day landing beaches.
Based on the hull of a Sherman from which the turret and gun had been
removed, the so-called beach armoured recovery vehicle (BARV) had the
hull sides extended in height by the addition of face-hardened armoured
plate. Although the driver was reliant on instructions from the
commander, the vehicle was able to wade in up to 8ft of water without
being swamped. A wooden pusher pad on the nose minimised the possibility
of damage when soft-skinned vehicles were being recovered.
Equally well known for their role on the D-Day beaches are the
so-called ‘duplex-drive’ (DD) amphibious tanks. Surprisingly, the
British Army had actually started to test amphibious tanks during the
First World War, but development did not reach a stage where the
vehicles were considered to be reliable. It wasn’t until June 1941 that
the Hungarian inventor Nicholas Straussler finally solved the problem of
making tanks float by the simple expedient of fitting a folding heavy
canvas screen to a frame welded around the top of the hull. With the
tank in the water, this increased the displacement of the hull to the
point where the tank was able to float with the hull below the
waterline. Compressed air was used to raise the screen, and it was held
in place by mechanical stays. A second drive system transferred power
from the track drive sprockets to rear-mounted propellers, and steering
was achieved by means of a rudder, and by rotating the propeller
mountings in a horizontal plane.
Much impressed by Straussler’s folding screen, Major General Percy
Hobart of the British 79th Armoured Division carried out swimming trials
in Portsmouth harbour, and the success of these trials led to the
selection of the British Valentine for the development of the
duplex-drive tank. At the same time plans were also put in hand to
convert Shermans for the role. Although most of the American, British
and Canadian DD tank crews did their preliminary training using
Valentines, it quickly became apparent that the Sherman was more
suitable for amphibious use and both M4A2 and M4A4 variants were
modified. The drive to the propellers was taken from the rear sprockets
using bevel gears, which meant that the tracks were running as soon as
the tank touched the beach, and the propellers were designed to hinge
upwards when not in use. The height of the canvas screen was also
increased when compared to the Valentine. DD Shermans were used, with
some patchy success, on D-Day, as well as during the Rhine crossing in
1945.
Shermans were also successfully adapted to carry the much-feared flamethrower weapon.
Back in 1940 the British company Lagonda Motors had constructed and
demonstrated a portable flame-thrower device that could project burning
petroleum-based fuel a distance of 100ft, and eventually managed to
extend this range to around 350ft. It was initially imagined that the
weapon could be used for the protection of shipping and airfields
against low-level attack by aircraft, but neither the Royal Navy nor the
Royal Air Force showed much interest and further development
concentrated on mounting the flame-thrower on either a truck or a
tracked vehicle. In this form the British Petroleum Warfare Department
(PWD) hoped that the weapon would prove to be effective against
pillboxes and strong points. By the end of July 1942 the flame-thrower
had been successfully adapted to allow it to be fitted to a tank, and
versions were produced using both the Valentine and the Churchill, the
latter carrying the flame-thrower fuel in a trailer. Known as the
Churchill Crocodile, this version was selected for production, but the
British and Canadian Armies also produced experimental Sherman
flame-throwers under the names Ronson, Salamander and Adder.
The US Army similarly produced flame-thrower devices that could be
mounted on the Sherman. In some cases the flame projector was fitted
into the co-driver’s periscope aperture or the hull machine-gun
position, while in other cases it replaced the main gun. In late 1944
the US 2nd Armored Division also adapted four Shermans to mount the
Churchill Crocodile flame-thrower.
Another role in which the Sherman was hugely successful was that of
mine clearance. Large numbers of anti-tank mines were laid by the
opposing armies, and in addition thousands of anti-personnel or land
mines also presented considerable danger to the advancing armies.
Various solutions to the problem of dealing with these mines were
proposed, including explosive devices, flails, rollers and ploughs, all
of them designed to be attached to modified tank hulls. Many were
immediately dismissed as being impractical, but others were developed to
the point where they were quite successful. Of these, the flail proved
to be the most effective.
Work on a mine flail had started in 1939 when the British
Mechanization Board had proposed that anti-tank mines could be exploded
in situ by means of weights attached to the ends of spring-steel strips;
the strips were attached to a revolving drum carried ahead of a tank.
It was quickly found that the device was more effective if the
spring-steel strips and weights were replaced by revolving chains, and
initial trials of what was described as the Baron Mk I were carried out
with a Matilda II tank. This was followed by the Baron Mk II, which was
equipped with a hydraulic raising and lowering system for the rotor.
During 1942 a simpler flail device, dubbed Scorpion, was developed in
the Middle East, and by the end of July 1943 Scorpion had been issued
for user trials, before being abandoned. However, during the previous
month there had been considerable progress with mounting a modified
version of the Scorpion on a Sherman tank, and this became the most
successful of the flails. Designated Crab, the first prototype was ready
for trials in September 1943 and the system proved to be very effective
at destroying mines and cutting barbed wire.
Other approaches to the problem of mine clearance included explosive
devices, ploughs and rollers. The Sherman Snake and Conger were both
explosive devices and consisted of a long hosepipe or cylinder of
explosive material that was intended to be pushed across a minefield and
detonated remotely, thus exploding the mines ahead of the advancing
tank. A similar device, dubbed Tapeworm, consisted of a flexible
hosepipe that was designed to be towed across the minefield by a flail
tank; once in position, it was filled with liquid explosive and
detonated.
Tank-mounted ploughs designed to expose anti-tank mines were
developed before the Second World War by agricultural engineers John
Fowler & Company, but despite considerable work the device never
lived up to its original promise. The British 79th Armoured Division
developed a version of the plough, dubbed Bullshorn, testing it in
conjunction with a Sherman. It was eventually abandoned in favour of the
flail, but a few Bullshorns were useful on D-Day for filling in craters
caused by exploding mines.
Anti-mine rollers had been developed in the years immediately
following the end of the First World War, and were designed to detonate
mines by simulating the weight of a tank rolling over the fuze. By 1937
John Fowler & Company had successfully trialled an anti-mine roller
attachment (AMRA) consisting of a girder frame that was effectively
pushed ahead of a tank, and which carried four heavy rollers. This idea
was adapted to produce the Sherman-mounted anti-mine reconnaissance
castor roller (AMRCR), which proved useful against anti-personnel mines.
Spiked rollers were also tested experimentally in the Middle East, and
one such device, dubbed Porcupine, was trialled in Britain in
conjunction with a Sherman.
The most successful anti-mine roller was the Canadian indestructible
roller device (CIRD). Constructed at the Canadian Army Workshops at
Borden during 1943, the CIRD consisted of two rollers of solid forged
armour-quality steel, 16in wide and with a diameter of 26in, each
weighing around a ton. The rollers were carried on trailing arms
suspended on a substantial cross-shaft, arranged to pivot some distance
ahead of the tank in front of each track. Helical springs were provided
to hold the trailing arms in the operating position. The CIRD was
standardised for use with both the Sherman and the Churchill in May
1945, although further development of roller devices was eventually
abandoned in favour of the more successful flail. Nevertheless, other
roller devices such as Rodent, Aunt Jemima, Earthworm, Centipede and
Lulu all achieved some degree of success. The last named brought a
little more technology to the problem by adapting the successful Polish
electro-magnetic mine-detection system for use with a tank. Finally the
remote ‘mine roller T10’ replaced the track system of the Sherman with
three huge rollers mounted tricycle fashion on swing arms.
The Sherman was also used, at least by the US Army, as a
rocket-launcher mount. Various systems were developed, but only two –
the ‘T34 Calliope’ and ‘T40 Whizbang’ – saw combat use. Dating from 1943
and used by the US 2nd Armored Division in France in 1944, Calliope
consisted of sixty 4.6in rocket tubes mounted in a frame above the
turret; the mount could rotate with the turret and the tubes were
elevated by a mechanical link to the gun barrel. Whizbang was also used
in combat in 1944/45, and consisted of twenty 7.2in rockets in a
hydraulically elevated box mount.
Consideration was also given to adapting the Sherman to provide what
the British would have described as an assault vehicle or ‘armoured
engineers’ vehicle’, and in April of 1945 a prototype was produced for
the ‘demolition tank T31’. The vehicle was constructed on an M4A3
chassis with the horizontal volute spring suspension (HVSS) system; the
thickness of the floor was increased to 1.5in and both a flame projector
and a ’dozer blade were fitted. The massive turret mounted a 105mm
howitzer, with a 7.2in T94 rocket-launcher to either side; the rocket
launcher incorporated a revolving feed mechanism that held five rounds,
and reloading could be carried out from inside the hull. A single
prototype, with a dummy 105mm gun, was delivered to Aberdeen Proving
Ground in August 1945, but the project did not extend beyond the
prototype stage and was subsequently cancelled.
Lastly, mention must be made of the inflatable canvas and rubber
‘Shermans’ that were deployed in 1943/44 as part of ‘Operation
Fortitude’ – the deception plan that fooled the Germans into thinking
that the invasion would come from Kent into the Pas de Calais region of
France. All kinds of tactics were used, including dummy tanks and
aircraft, fake radio traffic, and even the recorded sound of heavy
trucks apparently moving around dummy marshalling areas. Comprising four
separately inflated chambers, the dummy ‘Shermans’ were given realistic
markings, as well as having nuts and bolts and other detail painted
onto the canvas. Once inflated, the dummy ‘tanks’ were lined up in rows
and covered with camouflage netting. Inflatable ‘Shermans’ were also
used during ‘Operation Shingle’ at Anzio, in an attempt to confuse the
enemy regarding the real location of Allied tanks.
