US M2 Medium Tank

Sherman’s Granddad – The US M2 Medium Tank

Background During and immediately after World War I, the United States acquired stocks of European made or designed tanks, such as the French FT17 (also produced in the US under license) and the Mark VIII International, jointly developed with the UK as a heavy assault tank for use in the campaigns in 1919 and beyond. The War ended in 1918 and the US acquired significantly less heavy tanks than originally projected. During the years following the Armistice of 1919, a mixture of isolationism and the economic disaster of the Great Depression of the 1930’s led to a general atrophication of the US military in general. Research and development proceeded at a slow pace in a number of areas (eg aeronautics, development of aircraft carriers and heavy artillery for the Army). But new production was either deferred or very limited, especially for the Army. In this environment, the development of the US armoured forces suffered disproportionately, especially compared with the experimental work taking place in the UK and even in Germany (under covert arrangements in the Soviet Union). Stateside, in the first of a number of artificial divisions which would plague US armoured forces until late in WWII, it was decreed that only the Infantry branch

© Peter Hartup 2011 www.ammssydney.com

2 could field tanks, locking these weapons into the close infantry support role. The Cavalry was thus confined to relatively lightly armoured vehicles, wheel based – and of course, the good old horse. Overarching these doctrinal limitations was a general lack of funding from Congress, starting with general disarmament after the conclusion of WWI (the first “peace dividend”?) and continuing with greater force through the Great Depression. The US was not alone in this. The net result of these factors was that the limited development of armour in the US was focussed on light, cheap vehicles (and limited production of these), and the retention in service of the WWI vintage Mark VIII’s as the heavy armour component of the infantry. The Cavalry managed to acquire light tracked armour through the semantic device of designating M1 light tanks as “combat cars”. To be sure, some experimental developments were considered such as J W Christie’s revolutionary designs with a small handful of prototypes acquired, but essentially, the design and procurement pathways for US armour has been set until the radical break represented by the M26 Pershing in the mid-forties. This design would be based on the riveted hull, vertical volute suspension vehicles using rear-mounted, petrol fuelled, air-cooled, radial aircraft engines and carrying four or five man crews. While welded or cast hulls would be introduced over the course of production, these basic design elements would remain the same from the early light tanks M1, M2 and M3, through the medium tanks M2, M3 and M4 until the end of WWII and the introduction of the Pershing / Patton family of vehicles which served as main battle tanks in US service until the introduction of the M1 Abrams in the 1980’s.

The M2 Medium The downward spiral of events in Europe starting with the election of the National Socialists (Nazis) in Germany in 1933 led to general alarm in the West and gradually increasing calls for rearmament. Eventually, the lessons of tank development in Europe were recognised in the US, and a requirement for a heavier vehicle for the breakthrough and exploitation role was issued. This was to be based on existing automotive components and design, essentially a scaled up, improved development of the existing M2 / M3 light tanks. What emerged from this development process in 1939 was the M2 Medium. This design featured an angular, riveted hull constructed of flat armour plates, rear mounted 9 cylinder air-cooled, radial aero engine, and a small, well sloped turret mounting a 37mm gun.


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The combined fighting / driver’s compartment was essentially octagonal in shape with cylindrical machine gun rotors mounted in the four “corners” of the compartment. These rotors were cylindrical, providing limited traverse, with .30 cal machine guns in ball mounts. Suspension was based on the vertical volute type used in the light tank series, enlarged and strengthened. Tracks were initially 13.25” wide and of the reversible solid rubber block type. The driver’s position was located centrally in the hull, sitting stride the transmission unit, and controlled two fixed .30 cal machine guns mounted either side of the transmission and firing through the glacis plate. In addition to the six hull-mounted machine guns identified so far, the M2 carried an additional two weapons for anti aircraft defence. These were intended to be fired through two roof hatched either side of the turret using mounts attached close to the hatch openings. When not in use, these guns were often seen mounted in small brackets on the lateral sides of the turret. The basic M2 was quickly followed by the M2A1 Medium which featured a new turret similar in layout to that used by the M2 / M3 series light tanks. There were detail changes to the hull such as new pattern pistol ports, bullet splash deflectors on the glacis plate and extra shielding for the MG ball mounts in the rotors.

Overall, one gains the impression of a mobile pillbox! One additional feature is the mounting of two small armoured plates at the rear corners of the engine deck. These were angled in such a way as to ricochet bullets fired from the rear two rotor-mounted machine guns straight down – into any trenches the vehicle was crossing! In this and other design features of this tank we see an interesting cross-over from the WWI period (eg the perceived need to spray down into trenched being crossed) to the emerging doctrines of breakthrough and rapid exploitation which would dominate armoured warfare from WWII to the present day. The death knell for the M2 Medium was sounded in reports from military attaches in Europe describing the use of armour in the Polish and French campaigns of 1939/40.


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The need for heavier armour and armament was made clear, and experimental designs mounting a 75mm howitzer in the hull of the M2 (retaining the turret mounted 37mm for anti tank work) were rapidly developed into the M3 Medium (Lee / Grant), which served as a stop gap until the M4 Medium (Sherman) could be fielded with a 75mm gun mounted in a rotating turret. As such, the M2 Medium is truly “Sherman’s Grandad”.

References and Preserved Vehicles In most books dealing with the development of the Sherman, there is usually a picture of an M2 Medium. For some reason, I was attracted to this “hedgehog on tracks”, with its angular design hinting at what was to come with the M3 and M4. When I bought a copy of Hunnicutt’s “Sherman” (back in the days when you could still find them in shrink wrap on bookshop shelves, and at a price which didn’t involve a second mortgage), I was delighted to find 1:48 scale plans for both the M2 and M2A1. There were now no excuses for not starting this project. Along the way, I managed to acquire a photocopy of most of an operator’s manual for the M2. There are only two preserved vehicles of which I am aware - one at Aberdeen Proving Ground in Maryland, the other at the Patton Museum at Fort Knox Kentucky. I found two wonderful sets of images of the APG vehicle on the Internet. This vehicle is in fact a test-bed, on which a prototype of the turret developed for the M2A1 was mounted on a straight M2 hull. There is also a picture of this vehicle in Hunnicutt. Therefore, this vehicle is a great reference for the M2 hull. The Patton vehicle is a full-on M2A1. I have only seen in=mages of this vehicle in the virtual tour on the museum’s website. Unfortunately, the vehicle has been placed in diorama showing an engine hoisted above the engine compartment using what looks like an expedient timber log lifting frame. The display is built into a corner which means that an all-round view would appear impossible. Two points should be noted in using this vehicle as a reference: 1. The engine shown, while of the correct type (Wright Whirlwind R975) appears to be configured for a Sherman. The exhaust outlets are located at the top of the collector ring, whereas they are in an 8 o’clock / 4 o’clock configuration on the M2 series.


5 2. Exhaust mufflers appear to have been replaced by a rough approximation. The units look too small, and the holes are in a square grid pattern whereas the real items are larger and arranged in a diamond pattern. Apart from these points, the vehicle appears to be a well-preserved example of an M2A1. Also useful was a 1940 recruiting / propaganda film from Warner Brothers in glorious technicolour, “The Tanks are Coming”. This little 20 minute gem was an additional feature on a DVD “Operation Burma”, starring Errol Flynn! It revolves around the training of the new Armored Force which is equipped with M2 Light and M2 / M2A1 Medium tanks. Also present in the exercise sequence are XXX half tracks towing 75mm Pack Howitzers, M2 White Scout Cars and a CO who’s “a swell guy”! At least they didn’t say he was gay. As I said, it’s in brilliant colour and is a great reference for crew uniforms and markings. The final reference is a series of articles written by Charles Lemons (curator of the Patton Museum) which appeared in the now defunct Journal of Military Ordnance magazine. Fortunately, these have been expanded substantially into a new book from Schiffer, “US Armor Markings 1919 - 1940”. This is a must-have reference on unit organisation and markings for this period. It will be a classic in years to come, so get it while you can! Maybe get two so you can fund your retirement on eBay in years to come.

The Model - An Overview The M2 was constructed of butt-jointed armoured plates riveted to an underlying frame. I by and large followed this construction method, cutting and joining the plates to match the originals.


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I did not try to replicate the scale thickness of every plate - rather I settled on using the 1” (25.4mm) plate thickness overall for the hull structure. This scales out to 30 thou (0.75mm) in 1:35 scale. Apart from the 1.25” plating under the transmission and driver’s position, this was the thickest plate used on the M2, and in 1:35 scale provided a good basis for construction, allowing minimal internal bracing with virtually no distortion. Various aspects of construction are considered below: 

Suspension: Bogies are heavily modified Tamiya units from their M3 Grant kit. I suspect that these units are perhaps about 1mm too long.

But given where the distortion occurs I decided that it could be lived with correction would mean scratchbuilding the entire bogies (two halves) and I considered the gain in accuracy © Peter Hartup 2011 www.ammssydney.com

7 would not be worth the effort. Drive sprockets and rear idlers (including mounts) came from the Academy M12 kit, as did the transmission cover and drive mount. Road wheels were from the Tamiya Early M4 since they were made to fit the axles of the M3 suspension units without the need to precisely drill out the axle holes. 

Tracks: What can I say? Guilty as charged of masochism! Given that many of the suspension components resin casts of modified kit parts which would be super glued to the plastic hull, I didn’t like the idea of using rubber band style tracks tensioned correctly (i.e. to remove any sagging). Also there would the problem of cutting down any suitable M4 set to the correct width. Cutting down the width was necessary since the M2’s tracks ran well within the line of the overhanging fighting compartment / rear fuel tanks. Full width M4 tracks would be unacceptably wide in this regard. Accordingly, I settled on using the AFV Club T51 individual link tack set, with a single track shoe cut down to the correct width, and copies cast. And cast, and cast. Seventy nine per side plus spares.

As a rare concession to sanity, I used the injection moulded connectors from the AFV set.


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37mm Gun and Mount: The M2 used the early M21 mount (with shoulder brace) and an earlier version of the standard 37mm tank gun mounted in the M2 / M3 series light tanks. This featured a longer recoil / recuperator assembly beneath the barrel. As a base, I used the beautifully moulded 37mm gun and mount from the AFV Club M3A3 kit. The gun was modified with the longer recoil / recuperator assembly, and the mount modified with the shoulder brace on the left hand side.

To provide a good mount for the gun assembly inside the turret, I used the cast bulge from the front plate of the AFV M3A3 turret (which was just about the correct size and shape as the M2 equivalent), and after correction mounted it in the front plate of the M2 turret.


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The outer mantelet from the M3A3 was cut down and shaped into an M2 version. Instead of using the barrel from the M3A3 kit, I substituted a turned aluminium version from Jordi Rubio. The kit barrel looks OK - the JR version is a bit more refined in shape, and I figured it would be a bit more resilient over time. 

Rivet Detail: Rivet positions were marked out on the templates for each plate and each position was drilled out with a motor tool after “centre punching” with a needle held in a pin vise. The holes were then fitted with Grandt Line rivets of correct size and shape. (0.32” / 0.75mm round headed). Various bolt heads were shaved off the “spares” moulded onto the sprues of the AFV Club M3A3 and the Academy M3 kits. These spares were the source of rounded, slotted bolt heads used to secure the glacis plate, and of the flat hex shaped bolt heads used elsewhere. Riveted angle iron was fitted along the top of the lower hull, and on top of the rear fuel tanks up against the sides of the engine compartment. This was fabricated using Evergreen angle strip, riveted with Grandt Line rivets. One strip was thus fabricated, with additional strips cast from this master, then cut and fitted as needed.


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Finally, repeat after me, “rivets are my friends”. Keep this chant in mind. It will help. Really.

Finishing and Markings US Army vehicles were finished in Olive Drab overall. For a time, regulations stated that they should be finished with a coat of “spar varnish” which in addition to imparting a satin finish, tended to darken the appearance of the OD to the naked eye. In the Inter War period, for a time US armour carried full colour regimental badges on turret sides. Unfortunately, by the time the M2 came into service, this practice was dropped, and with it the opportunity to add a splash of colour! Markings were confined to alphanumeric company vehicle designators (eg F2) carried on the glacis and on engine compartment doors in the rear plate in white, with vehicle registration numbers in blue drab on hull sides at the rear on fuel tank side armour, though I have seen photographs of these numbers in white. Around the base of the turrets was painted a broken ring or stripe in a colour signifying the regiment. At the time there was only one medium tank regiment attached to each division, and the colour used varied with each division. In the 1st Armored Division, the medium regiment was the 67th Armoured Regiment, and the colour used was blue. However, a “splash” of colour can be found in additional markings applied to 1AD M2’s for the Louisiana Manoeuvres of 1941. These tanks carried the Armoured Force tri-coloured triangle on the glacis plate above the white tactical marking. So that settled the matter - I was building a 1st Armored Division M2 on manoeuvres in 1941.


US M2 Medium Tank

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