encyclopedia

SLIDE (WHEEL)

The condition where in the wheel tread speed is greater than the train speed. (NTSC)

SLIP/SLIDE SYSTEM

Vehicle system for detecting and preventing excessive wheel slips and slides during acceration and braking (Heavy Rail). (For Light Rail, SEE: Spin/Slide.)

SLOW ORDER

A location where trains must temporarily travel more slowly than maximum authorized track speed for that location. (TRB)

SLOW ZONE

Area within defined limits for wayside conditions requiring reduced operating speeds.