When a type of box car is described I regularly encounter the description single or double sheathed. Can anyone explain to me what this means ,what the outside looks like, how single and double can be told apart and how these cars can be distinguished from other types of box cars.
Double sheathed cars are the oldest type of boxcars on the road. They're called double sheated because they have wood sheathing (sort of like house siding) on both sides of the main support frame. They look like this:
http://www.steamfreightcars.com/gallery/boxauto/dlw45715main.html
Single sheathed cars are "newer", having first made their appearance on the rails around 1905. They're much like the double sheathed cars, except they lack the outside sheathing (their structural members are generally steel instead of wood too). They look like this:
http://www.steamfreightcars.com/gallery/boxauto/aa73918main.html
Ray Breyer
Modeling the NKP's Peoria Division, circa 1943