THE SIGNAL BOX

SIGNALS

SEMAPHORE SIGNALS

7. Shunting signals for multiple routes

A single shunting signal can apply to more than one route but sometimes it is necessary for such signals to make it clear which route has been set. An example might be at a yard outlet, where it is important to show whether the signal is cleared for a short dead-end neck or the main line. Indication of route can be critical at places where shunting movements are being propelled.

In most cases, the various types of shunting signal simply mirror their full-sized counterparts in their mode of operation.

Shunting signals for multiple routes

Miniature-arm bracket signal

Siding signals can be faithful reproductions of their full-sized counterparts.

This example shows a bracket signal where the left-hand of the choice of routes is of lesser importance.


Elevated Position Light signal with two routes
Twin disc signals

Ground disc signals can be mounted alongside each other to define separate routes.

It is possible to have several discs alongside each other (four was not uncommon) but this is often limited by space constraints.

Position light ground signal with two routes

To save space (and economise on cost), siding signals can be stacked above each other. The top-most arm always applies to the left-hand route, and the bottom to the right.

This arrangement is quite common with siding signals, unlike the equivalent signal with full-sized arms.

Elevated Position Light signal with two routes

Multiple ground discs can also be stacked vertically. This arrangement is more common than placing them alongside each other, owing the the limited space between lines.

Yellpw position light ground signal with two routes

The maximum number of stacked disc signals known to have existed is five, although only one such is known of. Those with four discs were common.

Ground Position Light signal with five routes
Shunt signal with Route Indicator

Another way to indicate large numbers of routes, or overcome space limitations, is to provide a Route Indicator to accompany a single arm.

Elevated Position Light signal with two routes
Disc signal with route indicator

Route indicators can also be provided with shunting discs, allowing large numbers of different routes to be indicated without the need for a complex signal.

Ground Position Light signal with five routes
Semaphore   Colour Light