A typical signal serving a simple junction has two arms. Here, the right-hand arm applies to the main line (fastest route) and the left-hand arm serves a branch or loop line.
If the both routes have the same speed limit, the arms are placed level with each other.
The design of the bracket structure, whether it be balanced, or left-handed/right-handed is of no relevance to the signals' meaning.
This is a three-way junction signal, for routes of three different speeds or importance.
An example of route importance would be where this signal was provided as a Slow Line home signal. Possible meanings might be:
- Slow Line to Goods Line home
- Along Slow Line home
- Slow Line to Fast Line home.
A three-way junction signal where one of the routes leads into a siding or loop.
In this example, the miniature arm for the siding is mounted low on the post on its own bracket but it could also be mounted on the same bracket as the other arms.
Sometimes, a route into a siding or loop is controlled by a ground signal mounted at the foot of the main post.
Occasionally, junction signals will be found with the arms mounted above each other. In this instance, the top arm always applies to the left-hand route and the bottom arm to the right. If there are more than two arms, they read left-to-right.
This type of signal is relatively rare, and is used only on goods lines and low-speed areas.
Another way to indicate large numbers of routes, or overcome space limitations, is to provide a Route Indicator to accompany a single arm.
As the signal is not as distinct as a multiple-arm junction signal, route indicators are only used in low speed areas.
