The rolling resistance of a railcar or cart with steel wheels on steel rails is much less than by using a cart with rubber, steel, or hard plastic wheels on normal surfaces like concrete, asphalt, or sand. The V-Move tug can pull a lot more weight when the items are on rails when properly configured, versus pulling on normal surfaces such as concrete. We rate all our tugs on our site and in our brochures for the lower limits of pulling a load on casters or wheels on a solid surface and not on rails. Take for example our V-move XL+ tug. The XL+ can pull a load on casters or wheels on a regular surface up to a load limit of 7.5 MT or 16,535 lb. However, the XL+ tug can easily move a load on rails up to 10 MT or 22,046 lb, which demonstrates how much less resistance there is when pulling a load on rails. See our example video of a V-Move XXL pulling both an electric locomotive mover and a railcar at the same time: https://www.xerowaste.ca/electric-tugs/xxl-4-kw-electric-industrial-tug/ If you have a factory and want to use a less-powered and more affordable V-Move tug to move a heavy load, then it may benefit you by installing and placing your load to move on rails instead of pulling a cart on casters across a concrete floor.