trailing

On a railway, trailing points are switches where the moving rail (or blade) converges toward the direction of travel rather than diverging away from it. When a train passes over trailing points in the normal direction, the blade lies flat against the stock rail, offering no obstruction. This contrasts with facing points, where the blade diverges in the direction of travel and must be actively positioned to guide the train onto the correct route.

Trailing points are simpler mechanically than facing points because a train can pass over them safely without requiring a properly set blade. The moving rail is pushed aside by the wheel flange and returns to its original position after the train has passed. This passive action means trailing points do not need to be locked during passage, and they require no facing-point lock mechanism or detector.

Typical uses and limitations

Trailing points are commonly found at the exit of sidings, storage roads, and branch lines where trains leave the main running line. They are also used where a siding terminates or where a secondary route splits off without the need for positive guidance. However, because the blade moves passively, a trailing point cannot safely be used where a train must be positively directed onto a specific route, such as at a junction with two active main lines.

The term reflects the directional logic: the points are passive in the trailing direction of travel. A driver approaching trailing points will pass over them regardless of blade position, whereas facing points demand active alignment. This distinction is fundamental to railway signalling and track geometry, affecting where signals can be placed, how points are interlocked, and what speed restrictions apply.