E-types rear drive
Anyone interested in the German Entwicklungsfahrzeuge or E-types will have noticed a discrepancy between one of the requirements for these vehicles, rear drive, and the drawings for the E-50 and E-75 and the reality of the E-100. To my knowledge no drawings and very little details exist on the E-5, the lightest supposedly in the series of vehicles. Unless you want to call the BMW PanzerzerstÃ¶rer â€˜Rutserâ€™ the E-5, but I strongly doubt it was intended this way. Furthermore, post-war interrogation of Dir. Jenschke of Adler (CIOS Report on the Development of New Series of German Tanks up to End of March, 1945) doesnâ€™t mention the E-5 and only talks about the E-10, E-25, E-50, E-75 and E-100.
The most reliable source on the paper panzers are the two Panzer Tract volumes dedicated to these vehicles (Panzer Tracts 20-1 and 20-2). In the volume on the panzers and jagdpanzers Thomas Jentz explains with text and drawings (by Hilary Doyle) that the E-10 and E-25 were intended for rear drive. The drawings of the E-50 and E-75 however show a King Tiger-like chassis with a drive sprocket at the front. Confusion may arise because the drawings show an idler wheel with teeth. You could see this as an indication for rear drive.
Drawing by Hilary Doyle, published in Panzer Tracts 20-1, ISBN-10: 097084073X â€“ For discussion purposes only.
In reality I believe we should first consider the technical implications of a rear drive. This means moving the transmission to the back. Considering the size of such a transmission an unavoidable issue arises: space! The transmission needs to be at the far back of the hull, hugging the rear hull plate. It will need to be installed transversally for optimal use of space. So where do you go with the aeration grills, the oil and coolant reservoirs, etc.?
To cut a long story short, I believe it would be quite impossible to fit all this in the hull as drawn by Hilary Doyle in the Panzer Tracts publication. An E-50 or E-75 with rear drive would result in different vehicle, probably with a higher engine deck and quite different from a normal King Tiger engine deck layout. So, what about the idler with guiding teeth? Considering the new suspension with far less road wheels, especially for the E-50, the track would have had much less guidance. Itâ€™s not hard to imagine that with that configuration tracks might very easily run off. Could the idler with teeth be an extra guidance aid? I believe so.
On the blog of Overlord Hilary Doyle himself commented on a heated discussion about the E-types transmission. It is a very interesting read.