Operation Infatuate II: Sherman tanks at Westkapelle

[MicS]

Originally Posted by David Herbert

In Michel Saberly's photos you can see that he has highlighted that these dozers has their Cat works numbers painted onto the front of the armour. These are in the 1T series which denotes that they are tractors built under licence from Caterpillar. A Cat built D7 would be a 7Mxxxx and a D6 would be a 4R or 5Rxxxx depending on track gauge. Cat works numbers, for say 7M D7s, started at 7M1 and ran to 7M9999. The next D7 would be a new prefix, in this case 9U1 which ran to 9U9999 and then another new prefix. Changes were brought in as required and a new prefix did not necessarily mean a new model but often did. There are a lot of 3T and 4T D7s about which are post war license built 7Ms.

There were reportedly 138 D7A and 45 D6A armoured angle dozers built. They were numbered 1T1xxx and 1T3xxx respectively. I have found evidence of the following extreme numbers:

D7A : 1T1007 & 1T1111, so the numbers presumably ran from 1T1001 to 1T1138

D6A : 1T3034 & 1T3060, which may mean that the actual total number built was over 45, or that there were unarmoured dozers within the 1T3001-1T3060 range, and/or that the armoured series started after 1T3001...

I'd be very interested to see evidence of numbers outside the above ranges

In addition to this manufacturer's serial number, armoured dozers also sported the War Department Registration Number, apparently nearly all starting with E243xxx (I only know of one clip showing a D7A E244xxx).

Michel