Bi-directional metro train. Can be coupled in multicar train. Steam'n'Rails ready, can be used with "realistic fuel" option, have both fuel tank with fuel interface and shulker (under Train controls) for manual feeding by coal. Hint for better coupling on screenshot.
WARNING! Do not disassemble COUPLED trains, uncouple them first, and drive by single to dedicated station, else they will break front side of one of them.