Hmm, in a case like this I wonder on how many steam locomotives it would take to haul a heavy train with or without helpers on the rear and sure it might not be practical to do this in real life but in trainz you can but beware of the consequences of long trains and then have people waiting at railroad crossings complain about it later so the best thing to do is at least haul 100 cars like the N&W did when moving coal but it is your call!