I received set 5112T for Christmas of 1952. At the time I was too young to remember it but I still have it. The link coupler bar was a clever solution that allowed coupling and uncoupling with link couplers. The key is flawless track carefully fastened down on a layout. Track laying on a floor will cause cars to uncouple from the 370. 370's also had poor traction so they would not pull many cars. Mine pulls 6 freight cars (two diecast) or 4 passenger cars (652, 652, 653, 654) on a layout with no uncoupling.