A failure of a subunit which by itself will cause a failure of the system or equipment.
encyclopedia
SINGLE TRACK OPERATION
Operation within defined limits governing bi-directional train movement over a single track on the Mainline.
SINGLE-SIDED LINEAR INDUCTION MOTOR (SLM, SSLM)
A linear induction motor that has a single primary winding on one side of the secondary or reaction rail. (TRB)
SINKHOLE
A depression in the ground caused by settlement of soil in specific area; usually due to underground water erosion.