Thanks for looking that up for me Greg.
With the new info, I looked in my TM9-2800 at all the trailers and I think I found it. There is a trailer with the description Trailer, 2 1/2 ton, 2W, Utility, Pole Type. Its purpose is to transport bridging equipment for the Corps of Engineers. The additional data says "the same basic trailer, equipped with special adapters is used to transport 5 different loads. Type 1 - Infantry support, raft equipment or pneumatic bridge equipment; Type 2 - Trestle bay load, 10 ton pontoon bridge; Type 3 - Triangulation tower; Type 4 - Utility power boat; Type 5 - Storm boats." The towing vehicle is specified to be truck 2 1/2 ton 6x6. The tongue is adjustable with overall length between 175 to 223 inches.
Hanno/John - does that sound familiar to what's in the museum?
Unfortunately I can't scan the page otherwise I would send it along.
Anybody know where there's a secret stash of bridging equipment trailers?