Chapter Ten
The first thing to stress when discussing the identification of Sherman Models is that with only a cursory glance it is a very difficult task. With further examination, and detail comparison it becomes a very difficult, time consuming and frustrating task! Essentially they do all look the same to the novice, and it is often in the small detail such as type of periscopes fitted, locations of hatches or shapes of castings that the identification process can begin to be addressed. Relying on the shape of the transmission cover at the front of tank alone however is not sufficient. That method has often been given as the sure-fire method to identify a Sherman variant. The transmission covers appear to have been interchangeable with all models, and therefore with workshop and repair facilities at the front line and in rear areas working overtime to replace damaged vehicles this feature alone cannot be a definitive identification trick to use. Look at the chaotic repair depot scenes in the American chapter and you see live ammunition rolling around the workshop floor next to welding equipment and oil coated engine filters. Were they really going to take the time to request a three part cover when a pile of spare solid one piece cast covers lay outside? Plus there were many ‘in service’ adaptations which were carried out by each individual crew, or Unit modifications to the basic tank configuration. Views of the rear armour plate provide further assistance. The M4 rear plate is more vertical, and shallower often with a cut-out that reveals two of the engine’s air cleaners and small exhaust pipes compared with the deeper deck which overhangs the rear plate of the M4A4 type. The M4A2 and M4A3 also have the deeper rear plates but the M4A2’s exhaust system is unique to its type and looks nothing like the M4A3 or M4A4 variants’ exhausts. These have huge exhaust pipes with a single rear engine access hatch door. Later model M4A2’s and M4A3’s were fitted with exhaust deflector units. The stowage areas for tools on the rear decking and rear engine access door layout also provides indications of the type of engine and variant one is looking at. Only by studying many different photographs will the reader begin to seek out the differentiating features that mark out each model. In brief - look at rear decking, type of hull construction, exhaust layout, transmission covers, turret and gun type, suspension units, and engine access doors among the main distinguishing features.
THE BASIC TURRET TANK MODELS
The tables in this chapter give an idea of Sherman turret tank production and acceptances during Second World War, however to appreciate the extent of the Sherman family of AFV’s one must consider the range of adaptations that were built on the Sherman M4 chassis too. Not illustrated in the pages of this book in depth are Tank Destroyers like the M10, Achilles and M36 Jackson nor are Self-Propelled Gun Howitzers like the Priest and Sexton featured. There were other variants such as Canal Defence, Troop Carriers, Flame Throwers, Rocket Launchers, Prime Movers, Experimental and Test vehicles.
Unfortunately the parametres set for this book have limited the photographic scope. Thus only some examples of BARV, ARV and other funnies have been illustrated. To help further identify models within the family of Sherman vehicles here are some distinguishing features on model variants in the basic turret tank models. Letter designations denote the following:
‘T’– Experimental Type, ’E’– Experimental Modification, ’M’– Standardised Type,
‘A’ – Standardised Modification and ‘B’ – Standardised Chassis Variation.
Here is a basic guide:
MODEL M4
Featured welded hull, cast turret, and 75mm gun in an M34 gun mount. Vision slots were fitted into front hull. Differential (transmission) housing was three part, bolted together. The earliest examples, after standardization in October 1941 had the track return rollers mounted at the top centre on the bogies. Engine mounted was the Continental R975 9 Cylinder Radial. Production continued until January, 1944 and later models had the 75mm gun mounted in the M34A1 gun mount. The later M4’s also had the three piece differential cover replaced by the sharp nosed design manufactured as a one piece casting. Therefore later M4’s are often misidentified as M4A2 variants. Sand shields were factory fitted on the M4.
MODEL M4A1
Two months after the standardization of the M4 in 1941 came the M4A1 which featured a curved cast hull to lessen the impact of direct hits after testing raised concern. The first Sherman accepted into British Service ‘Michael’ was an example of this model and is illustrated in this book. It used the three piece bolted differential cover and also direct vision slots in the front of the hull. These did not rotate, hence ‘direct’ vision slot - front view only. The 75mm gun was again mounted in the M34 mount. Track return rollers were centred atop the bogies on early models and there were ports cut in the front of the hull to allow the bow mounting of two fixed .30 calibre machine guns. These were later sealed and deleted by end of 1941. The engine used was the Continental R975 Radial engine. Later production models rolled off the line with track return rollers moved to the rear of the bogies, a cast one piece rounded diff cover and appliqué armour neatly welded to the turret and hull sides for added protection of ammunition compartments within. Field applied additional armour plate usually has a much rougher welded seam where it had been applied to the hull. Some were factory fitted with gun travelling locks attached at the front of the hull.
MODEL M4A2
Also standardized in December of 1941 this model had a welded hull with a cast turret and looked similar to an M4. Power to propel the tank was provided by the twin General Motors 6-71 Diesel engines. Earliest production tanks had the 75mm M3 in an M34 mount with vision slots for driver and co-driver. Differential cover was of the three piece bolted type and it still retained the twin fixed .30 machine guns mounted in the bow. The track return rollers were centred atop the bogies. Later versions of the M4A2 used the return rollers mounted at the rear of the bogies. Complicating identification, some early models used the one piece differential cover too, and later models of the M4A2 used this cover exclusively. 75mm guns were later mounted in the M34A1 redesigned mount and appliqué armour was added. Plates were welded onto the hull as hatch guards, especially in front of the driver’s position on what has become known as the driver’s hood. Gun travelling locks were fitted, and sand shields, at the factory although did not last long in the field. Battlefield travel soon tore off various components of the bolt together sand shield, which was made of much thinner steel than the armoured hull. The very late model of the M4A2 used the 47 degree hull front armour plate, which produced a distinctive silhouette rising to the driver’s/ co-driver’s positions. Enlarged doors for the driver and co driver were added in this later production. The diff cover used on these very late production models was of the sharp nose type only. The best way to identify this variant is by looking at the rear deck layout as the diesel engined M4A2’s had a distinctive access hatch layout, of course not every photograph affords this opportunity!
MODEL M4A3
This model became standardised in January of 1942, featuring a welded hull and cast turret. The 500hp Ford tank engine was the power-plant used to motivate the M4A3. A huge eight cylinder, liquid cooled V-Type engine specifically designed for tank use. The M34 gun mount was used in early production, vision slots were fitted and the diff cover was of the cast one piece rounded nose type. Return rollers were mounted on the rear of the rollers. Later production models of the M4A3 had periscopes fitted instead of direct vision slots, and had sand shields. The M34 gun mount remained in the turret. Changes occurred with the very late production M4A3 which mounted the 75mm gun in the M34A1 gun mount, used a vision cupola for the commander and innovated the small oval hatch above the loader in the turret. 47 degree hull front armour plate was also used on the very late production models, with enlarged driver’s doors, and the cast one piece sharp nosed differential housing. Vertical Volute Spring Suspension system and sand-shields were fitted at the factory. The front armour plate also had a gun travelling lock bolted to it.
MODEL M4A4
Standardised in February 1942, and similar again to the M4 it was powered by the unique Chrysler 5 block Chrysler Multibank engine. The hull had to be lengthened to accommodate this new engine and this was noted as the first large-scale significant change to the basic Sherman design. It was elongated by 11 inches, (28cm). Consequently the bogies were spaced further apart than on other models. A longer track with 83 shoes, compared to 79 on other M4 variants was necessary. This spacing can be measured in photographs as being approximately three track end connectors long, whereas other models are only two connectors length apart. M4A4’s can be identified by the tubular grille featuring on the upper rear deck directly behind the turret but these also feature on the M4A6. Earliest models mounted the 75mm M3 gun in the standard M34 mount, used vision slots in the frontal armour and were fitted with the three piece bolted differential cover. The late 1943 production model had the M34 gun mount replaced by the M34A1 and earlier vision slots were deleted. Periscopes provided front view for the drivers when hatches were battened down. The late production types still retained the three piece cover for the differential. The Chrysler designed M4A4 also features a small welded plate to either side of the turret splash ring, protecting drainage holes, which was also used on the M4A6 - These are the only types of Sherman with this feature.
MODEL M4A5
The M4A5 was produced in Canada as the Ram II tank and was only given the designation for record purposes by the US Government. The Ram II was not a Sherman variant in reality but is illustrated in the Home Army Chapter of this book, and is noted to help distinguish the other Shermans.
MODEL M4A6
This version also had the lengthened hull the same as the M4A4, but this time to accommodate an Ordnance RD-1820 air cooled diesel engine. The longer tracks with 83 shoes were also used. Interestingly the hull of the M4A6 was a composite made of rolled and cast upper hull utilising the cast one piece sharp nosed differential housing. Main gun was the 75mm in an M34A1 gun mount and suspension operated on vertical volute spring system. Sand shields were fitted in the factory as was some appliqué armour. Only a small number of M4A6’s were constructed (75) between October of 1943 and February of 1944. The US Army declined their issue however some were sent to the United Kingdom. They are identifiable in British service by the large curved exhaust cover on the rear plate among other features.
MODEL M4 (105mm Howitzer)
US armament design studies had predicted the mounting of the 105mm Howitzer in a turret tank as early as 1941 and tests had been carried out in March of 1942 at the Aberdeen Proving Grounds in Maryland. The idea being to increase firepower additional to the speed of a medium tank. Prototype test models termed M4E5 & M4A4E1 had been built, tested and deemed successful. They lead to standardised versions known as the M4 (105mm Howitzer) and M4A3 (105mm Howitzer) in July 1943. Production followed a year later with the M4 105mm Howitzer mounted in an M52 gun mount with co-axial .30 calibre machine gun. 66 Howitzer rounds were carried and distinguishing features included a gun ring hatch for the commander and a small oval hatch in the turret top for loader entry. The differential housing was of the sharp nosed one piece casting, and the hull front also featured the 47 degree slope. Vertical volute springs and sand-shields were initially factory fitted but later models featured a wider track and horizontal volute suspension system.
MODEL M4A3 (105mm Howitzer)
The M4A3 105 can be distinguished by vision cupola fitting for the commander and again the oval loaders hatch on the turret top surface. Two ventilators were also fitted on the turret top. 47 degree hull front featured and the cast one piece sharp nosed differential cover completed it’s frontal profile.
MODEL M4A3E2
Recognition that the second front would require an up-rated assault tank promoted development work which began in early 1944 to redesign the Sherman. To fullfil this role as an infantry support vehicle in an assault situation a new tank altogether was required, but the Pershing T26E1 had not yet passed it’s testing stage or acceptance for issue within the US Army. Standard M4A3 tanks were earmarked for beefing up to take the punishment an assault tank might expect in the meantime. Additional armour was welded to front surfaces, creating a thickness in places of four inches. New turrets were designed and fitted with the 75mm M3 gun. These had six inches of frontal armour, and additional rolled plating to the top of the turret. Unfortunately the increased armour, pushing the total weight to forty-two tons meant a decrease in speed. 254 Assault tanks of the M4A3E2 type were ordered and these were produced in Michigan at the Grand Blanc Tank Arsenal from May to June, 1944.
SHERMANS DISTRIBUTED UNDER INTERNATIONAL AID PROGRAMMES
TURRET TANK ACCEPTANCE FIGURES FROM 1941-45 PRODUCTION
The models that passed final inspection for issue
BRITISH ARMY WARTIME DESIGNATIONS
FOR SHERMANS ACCEPTED INTO SERVICE
US ARMY TECHNICAL MANUAL AND SUPPLY CATALOGUES
Wartime Technical Manuals (TM’s) describe the technical operation of various mechanisms within the tank and also basic field maintenance procedure, but the Supply Catalogue (SNL – Standard Nomenclature List) is a huge listing of every constituent part used in the assembly of each model of tank. These were used as much more detailed reference for repair and overhaul in the workshop. Here is a reference list to help identification of original or reprinted manuals as they occasionally turn up for sale on auction websites such as Ebay, and might even turn up in your second hand bookshop!
