For hauling fill to the washouts I would suggest an old five yard box from an old dump truck mounted on a scissors hoist. Mount that on a simple four wheel car . Power the hoist with a gas engine. Use a wooden 4x4 between the dump car and locomotive that will break, saving the loco in case of a derailment. If I didn't live so darn far away I would scrounge all the parts around here.
Mike Nix
