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Old 29-10-20, 00:27
David Herbert David Herbert is offline
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Join Date: Mar 2010
Location: Ayrshire, Scotland - previously Suffolk
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Quote:
Originally Posted by Alex van de Wetering View Post
Avalon is somewhat different from most Crabs in that it has a direct vision M4A4 hull, which means the covers for the periscopes are fitted to the hatches rather than fitted on the hull itself.
Alex is quite right here but he is referring to the special covers fitted only to Crab hull periscopes. His first photo shows them both rather well.

With ordinary gun tanks the hull hatches of direct vision port Shermans are exactly the same as later small hatch Shermans. The difference was that the direct vision ports were replaced by a mounting for another identical periscope to the hatch periscope. This second mounting could be adjusted for elevation but not turned sideways as the hatch mount could be. Both mountings had a hinged sheet metal rain cover which was sprung to the closed position. The hatch periscope mount could also have a guard made of about 8mm diameter steel rod fitted to prevent damage to the top of the periscope but this was a later feature and is often missing even on later tanks.

However, on very early Shermans it was possible to open the hull hatches so that they laid flat on the top of the hull if the periscope was not mounted. This was changed at ABOUT the time that direct vision ports were deleted and a stop was added that limited hatch opening to about 135 degrees so that the driver's head was protected a bit from the side and the hatch could be closed more easily in an emergency. Thus if the hatch can be seen to be lying flat on the hull roof, the tank is PROBABLY a direct vision port one. Many tanks were upgraded to prevent the hatch lying flat so it not lying flat proves nothing about direct vision ports.

David

Last edited by David Herbert; 29-10-20 at 00:49.
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