The Japanese used barges extensively for resupply in the Pacific, especially in and around the Solomons and New Guinea. Hunting them was a favorite pastime of US pilots. Depending on the terrain, they might be an alternative to truck convoys. Many sported light AA, so they would be more of a challange than the convoys. Due to their slow speed, you'ld need to have more than one running between island bases, say 15 minutes apart. The big convoys could take the place of trains, of course.