The ends of the train units are fitted with plastic coupling supports (8) which have sprung contact tags (13,25) on the undersides. The ends of the contact strips are shaped into grip profiles (28) which locate in shaped recesses (24,12) under the opposite coupling support. The tags provide an automatic coupling as well as electric connection between the units. Each rags is electrically connected to a wiper tag to the rails. The grip profile on the tags has a sloping side for the coupling direction and a steep side for coupling grip. The tags are guided into the coupling position by sloping profiles (11).
