That is really interesting as I thought all the 3T's in the serial book were Made in Peoria. If it is a 3T it would be a 1945 which is the proper time frame.  On the webpage link above under the Stuart tank it has a series of photos and on the bottom row of photos is a D7 Cat with a blurb about ACF building Cats after they were done building tanks.

www.berwickstuarttank.org/general-clean 

The photo says that the ACF built over 21,000 D7's for the Military.
According to the SE# book under 15,000 D7's were built in 1944 and 1945.??????  That includes 3T, 4T and 6T machines.

Looks like we need to find a good Cat historian to check it out.



 

Hi, Folks.
Being in time of war and for military use, it could also have been a 4T or a 6T. series. I think that the 6Ts were a pretty rare beast and made for the navy.

Have him look for Cat serisl #.

Just my 0.02.

On another webpage I found that supposedly ACF built all the 4T military tractors for Caterpillar in 1944 and 1945 for a total of about 10,000. (5000 each year)
usautoindustryworldwartwo.com/caterpillar.htm
Production data is about 4 pages below all the photos on the above webpage

With that info it seems all the 4T tractors were built by ACF in PA. SE# book says all were built in Peoria.???

This was all news to me. Interesting article on this webpage about the D7 4T all built in PA at ACF and not Peoria

usautoindustryworldwartwo.com/americancarfoundry.htm

EXCERPT FROM WEB PAGE:
Caterpillar D-7: This is one of the untold stories of industrial production of World War Two. Much of the following information in this section is from "The D7 Tractor - A Visual History of the D7 Tractor in U.S. Army Service 1941-1953" by David Doyle published 2021 by Emfour Publishing Company. Military historian David Doyle's excellent research has unearthed new information that had not been published or known until early 2022. I will refer to it as 'David Doyle's D7 Book.'   

Caterpillar could not meet the increased demand for D7 tractor in 1943 due to other military commitments, including but not limited to road graders, other construction equipment, marine engines, generator sets, M4 Sherman tank transmissions, and other sizes of tractors. Therefore, in July 1943 the Army Corps of Engineers brought American Car and Foundry in to also build D7 tractors as a subcontractor to Caterpillar which supplied the engines and several key components. This is one of the reasons that it was not until David Doyle's D7 Book that there was a better understanding of the number of D7s American Car and Foundry built and when they were built. The other reason is that Caterpillar did not want it known that another company had to build the tractors it could not produce, so the whole program did not have a lot of publicity. 

Between March 1944 and the end of the war, the American Car and Foundry Berwick, PA plant built between 11,045 to 11,959 Caterpillar D-7 tractors. This compares very favorably with the 14,609 (Table 5.) Caterpillar built. Most contracts for military equipment were cancelled starting September 15, 1945. Half of the tractors had already been built with many in process that could be built out and completed. Also, as the tractors were under subcontract, the Berwick plant had to wait until it received the stop order from Caterpillar.

There is additional information on the number built. According to David Doyle's D7 Book, the U.S. Corps of Army Engineers reported at the end of June 1945 that as of the end of May 1945 the Berwick, PA plant had produced 9,215 D7 tractors. These are confirmed as being built. The rest of the quantities were planned, so I will assume the actual production reflected the schedule. This information is in Table 4 below.

The D7s built by American Car and Foundry were given 4Txxxx serial numbers. However, both the David Doyle D7 Book and "U.S. WWII Caterpillar D7 Track-Type Tractor" published by Tankograd Publishing 2011 indicate that the last serial number for the American Car and Foundry 4T serial numbers was 4T9999. The Army Corps of Engineers was not going to let production stop at Berwick, PA because Caterpillar had arbitrarily capped the number of serial numbers. One of two things happened, either Caterpillar added more serial numbers to the 4T series, or the D7s built at Berwick were given 3T serial numbers, which was the serial number sequence for the D7s built by Caterpillar. I don't see the later as being the case, as Caterpillar wanted to keep the build location of the tractors identified in an easy manner.

The D7 Tankograd book indicates that Caterpillar would start a new series when the production run extended beyond 9999. This is not true. There is a 1951 D7 on display at Fort Leonard Wood, MO with serial number 3T19549. Therefore, I believe Caterpillar extended the 4T series beyond 9999 and the production line at Berwick, PA continued to crank out D7s until the war ended.

Hi, D4Jim.
Interesting stuff. Thanks for doing the 'excavating'.

Just my 0.02.

Hi, Kurt.
There were some Cat 12, or maybe 212, graders made in DowNunda during WW2 by the then Cat Dealer in New South Wales, Waugh and Josephson. If my memory serves me rightly, they had the prefix, 'W', in front of the serial #. Lance Jones, the foundation president of Chapter 18. actually found one somewhere in the U.S.. Just HOW it got here, I have no idea.

www.hcvc.com.au/forum/oldjunk/6171-caterpillar-12-grader

It is worth noting that Cat took away W&Js license in 1946 and gave the 'license-to-build' to Steelweld Pty Ltd, a Melbourne-based company, who built graders and other Cat-designed equipment, mostly attachments, until Cat bought them out somewhere in, I think, the 1970s.

www.facebook.com/ACMOC-Chapter-19-181924...ars/250895086572969/



I also seem to remember that a company named Ruwolt built one D7 DowNunda near the end of WW2 - even found a link to discussion of it:

www.acmoc.org/bb/discussion-d72/1496-4t-d7

Just my 0.02.