BR safety poster, aimed at children. Play Safe - Don't Play on the Railway, shows 10 illustrated scenes of 10 boys playing on the railway, one killed in each scene, until last child decides to stay off the line. 1973. Printed by Collier Searle, published by British Railways Board.BR safety poster. Play Safe - Don't Play on the Railway, 1973. Format: double crown. Dimensions: 30 x 20 inches, 508 x 762mm.