Part of the Sherman development during WW2 was an attempt to increase its power and one such vehicle was the M4A6 which was to receive a modified Wright air-cooled radial. The end result was a fuel injected diesel engine by Caterpillar - known as the D200A - which could run on anything from crude oil to 100 octane petrol. It developed some 450hp with 1470 ft/lb torque @ 1200 rpm. Initially, standard M4A4s were used with a slight modification to the rear engine deck to accommodate the larger engine.
The first vehicle was designated M4E1 and began testing at the Caterpillar Proving Ground in December 1942. After ironing out initial problems, Chrysler began production in 1943 but used an M4A4 hull with a cast nose similar to the large hatch M4A1. However, only 75 vehicles were built before the decision was made to concentrate on the M4A3 despite it being considered superior in performance than any other M4 series tank. Built vehicles were assigned to training units in the U.S. and none saw active service.

The plan for this build is to combine a standard V hull with that of a 1c - Tasca supplying both of the hulls.....





The 1c is based on the M4 version so has a shorter hull than the M4A4. The plan is to cut the noses off both hulls and graft the cast section onto the M4A4 hull. A few minor changes to the engine deck along with a later production turret with an oval loaders hatch should hopefully result in a reasonable accurate M4A6. There is not a lot of info or photos around but hopefully enough to do the job.

Gary

The 1c hull is the easy one to cut - just cut along the weld seam ...



The V hull is marked up ready for cutting.

Gary

Ready to join. Will need a little work - especially around the turret ring - but nothing too taxing...



And with a little care, may also end up with an M4 hull too

Gary

An amazing project, can't wait to see how it shapes up!

I really like you Shermans

Great work, can't wait to see this one.

Do you know wen you will paint your other builds?

Martin

Cheers chaps

Martin. At least the end of the year as we're having a new house built at the moment and current painting area is being used for storage. So all I can do is build for the time being.


So far, so good....





Gary

More progress. The lower V hull is constructed as per normal with the exception of the bottom sponson plates which are from the 1c (note the rounded corners to match the cast nose). Small extension are added to the rear each side to match the V hull's increased length....



Later type E 8543 Final Drive Assembly (FDA) is from The New TMD....



One note of interest with regards to the FDA, is that all Chrysler built M4A4s (V) left the factory with the 3 piece noses. This, to the best of my knowledge, is the only M4A4 based version which left Chrysler's factory with a single piece unit.

A relief to see that the upper and lower hulls are a perfect fit



Gary

Appliqué armour is added next - modifying standard M4A4 plates to suit. Welds are then added using Archer resin weld decals...





Gary

This is very interesting..... as usual.

Yes it is, the kind of stuff I love to see

Thank you gentlemen

Made a start on the rear deck. Gone is the distinctive radiator cover and single piece main hatch. In it's place are two separate large hatches...



Gary

Very nice job, Gary, and very interesting project.

Would it also have been possible to extend the length of the engine deck area on the hybrid hull to achieve the same effect? Perhaps more difficult to hide the seams in that case, or would that result in a back end with an incorrect angle/slope?

Cheers,
Sven

Thanks Sven

Those were my exact thoughts which is why I went down the route I did

Air intake panel 99% complete along with extra filler cap....



Gary

Nice

Thanks Clayton.

Rear deck is coming along nicely. Tricky bit was shaving the deck hinges off the original kit parts to graft them onto the new panels. The hump was scratch built with Mr Surfacer giving a cast effect. Lifting handles are 10amp fusewire while bolt heads are from spare V hull parts...



Gary

Asuka hulls are great for conversion projects since you can order them separately from their web site. I created a conversion for one of their M4A4 hulls to a small hatch M4A3. The radio pot for the M4A4 is not an exact match for the Ford M4A3 but otherwise its a pretty easy way to get a small hatch M4A3.
http://www.click2detail.com/store/p102/1%3A35_Small_Hatch_M4A3_Engine_Deck.html

Started adding upper deck details. Welds are again from Archer and additional tow cable holder (seen in upper right of pic) is shaved from an old hull and grafted on. I've opted for kit tools this time round - tidying them up where required. I'll add a couple of PE brackets to improve the looks for the axe and pick while footman loops are made from 5 amp fusewire with the 'welds' being made from lead foil punched out using my 'Nutter'. More to follow....



Gary

More progress. Leather tool straps are made with lead foil and Aber buckles. Small PE chains are also added to the filler caps and other PE details added where necessary for the tool brackets...



Gary

Rear end just about complete...



Gary

Meanwhile, up at the front end....



.30 cal barrel is one of the sublime brass offerings from Master. Hatches are dry fitted at this stage.

Gary

Light and siren guards added along with siren wiring. Grey 'blobs' are casting nubs - the one at the top also acts as a drain for the exhaust blower. Note the 'short' D28730 travel lock which was fitted to this version...



Gary

Upper hull is just about complete now. Hatches needed a little extra detail added to replicate the hinge pins and rear upper hull tow cable bracket is added using Aber parts....







Gary

Most period photos show these vehicles were fitted with sand shields so am going down that route using parts from the spares box...



Welds yet to be added to the mounting rails.

Gary

'Quick release' type tow pins are added after being scratch built from brass tube and spare PE. The foot steps are made from strip styrene...



Gary

Next step will be the VVSS suspension. Tasca's rendition is very good, but still requires a fair amount of prep removing seam lines. Below are the major components ready to go...



I only have the earlier type units and while it is still okay to use them, this version could really do with the later type with the upswept roller arms so have ordered a set from Asuka (Tasca) . I will make a start by getting the road wheels and arms all don, while waiting for this set to arrive.

Gary