Switch stands are a mechanism for the operation of switch points or movable parts. There are two sizes and mechanisms: High and Low, Semiautomatic (S) and Rigid ( R).
Semiautomatic switch stands have a mechanism (spring) that allows trailing when traffic flows in the same direction as the switch points. Trailable switch stands are capable of automatically switching the points of the turnout without manual operation. Rigid witch stands are not trailable therefore manual operation has to be supervised by qualified personnel.