Just what is it? I recently received the AFView book on the Pacific with some great photos of the armor used there. The book continually refers to "Composite Shermans" without any variant (M4A1, M4A3, etc.). How does one identify these vehicles? They appear to possess the cast hulls of an M4A1 on the forward portions of the hull with the welded rear portions of an M4A2 or M4A3. Is this correct? Is that what makes them 'composite'? Thanks for any assistance you can offer.
Composite hull Shermans were the final variant of the basic M4 hull and did combine a cast M4A1 type front end (glacis) with the rear half of the welded M4 hull. This was right before the M4 series was dropped for the much better M4A3 type.
The M4A6 was another variant with a longer hull and a big radial diesel engine, and it used the same concept as the M4 composite hull.
Next to last. The last was the "big hatch" welded hull as used on the M4 (105). The composite structure was a DTA (Chrysler) invention that would have been used on all of the "ultimate" Shermans but FTA (Fisher Body) was able to fit larger driver's hatches into a welded plate hull so the Army went with that starting in 1944
As Cookie said, it was a late-model M4 with cast front end, and was the last
75mm armed M4 produced (this construction was also used on the 75 M4A6 tanks built in August, but they all went to training and evaluation units at Fort Knox and possibly Aberdeen). It may be useful to know that the production dates were late 1943 (August to December as I recall), so they turn up with US Army units in the Pacific (particularly the Phillipines), and some were rearmed as flame tanks. Some also turn up with US units in France, and the British received quite a few that they rebuilt as 17 pounder-armed Firefly tanks (Sherman Mk 1C). Dragon had a kit of this a while back, and hopefully it will reappear soon. Gerald Owens
No, the US Army had a policy against diesel engines in tanks, a policy that was not reversed until 1960. Despite the greater fuel efficiency and reduced fire risk of diesel engines, the Army just had too many gasoline-engined vehicles, and it made logistical sense having one fuel for all machines. Then, just to screw up a perfectly good rationale, the Army accepted the diesel version of the M10 tank destroyer, simply because it was ready for production first. Diesel-powered Stuarts were used only for stateside training (though some may have been supplied to the Allies). The M4 and M4A1 used a Wright Continental air-cooled gasoline-powered radial. The only diesel Sherman variant produced in quantity was the M4A2, although it had a pair of diesel bus engines, not a Guiberson radial. It was supplied to the US Marines (US Navy small craft already used diesel engines, so supply was no problem), and as Lend Lease to the British and Commonwealth forces, the Free French and the Russians (who got over half of them, including all of the 76mm models). A few M4A2's were issued to US Army units in Italy in 1944 due to a tank shortage, and were well-liked for their hill-climbing ability. The M4A6 had a radial diesel, but was canceled in 1943 after just 75 were built due to the previously mentioned policy on fuel. They were used at Fort Knox for training. Gerald Owens