iroquois1963
the length and the width of barges, but it is the dimensions(size) of the box which bothers me,
Ah, part of the confusion will be becasue the US Army used both one-piece (to purpose) barges, and the made up from modules "barge units."
The latter were intended more for creating combat bridges, as the floting parts could be assembled some what like Lego bricks to need.
As part of learning to use those block, Army bridging units had created "barges" to use as ferries, for when that was a better answer for a temporary bridge.
Army bridging units are a fascinating mix of engineers and sappers, with an elan mixed of pragmatism and imporvisation.
The air-portable platform noted above was criticized afterwards as not being very adaptable for waterways with large tidal variations. But, mostly for not having nearly enough room for all the things artillery requires. Which meant needing to detail a "Mike" boat (either an LCM-6 or LCM-8) or a barge to the location. Which rather defeated the whole air-mobile concept of the thing.
The US Navy's Rivierine forces also complicated this, by using at least one "Ammi" (and amphibious landing modular) barge as a gun platform.
This was a point of some study for those going throug the USN's Riverine School.