Tugs on Flatcars
I found an interesting image of two US Army tugboats on 3 flatcars on the Wisconsin Maritime Museum's web archive. This is on the Ahnapee & Western Railway in Sturgeon Bay, WI in 1943. Hulls on the end cars, pilot houses on the center car. I would assume that the openings in the deck would have been covered with canvas. Could be a nice project for those little Sylvan tug kits.
from the collection: https://wisconsinmaritime.pastperfectonline.com/vocabulary