The special Hornby coupling unit allows rolling stock to be connected together, or separated, without having to be touched by hand. If fitted at the beginning of each siding, realistic shunting and sorting operations can be carried out. The shaped base track is designed to guide the wheels into position when you are placing an item of rolling stock on the track ('railing' it).When any two items of rolling stock come together anywhere, other than over an uncoupling ramp, their couplings automatically lock together and when the train is pulled away. Even travelling over uncoupling ramps, the couplings remain connected. When a train is pushed over an uncoupling ramp so that two connected couplings are stopped directly over the ramp, the couplings will automatically disengage and the locomotive can be driven away, leaving behind the uncoupled part of the train.