Chris Gadsby and Richard Foster guide you through the different types of railway signal and where they should be placed on your layout.
We guide you through the correct placement of signals on your layout.
Railway signalling: for the layman, it’s a confusing web of seemingly nonsensical words – ‘inner home’, ‘outer home’, ‘advanced starting’ and so on. And to the layman, there appears to be no sense in where they’re positioned, either.
That’s not true, of course. Signals are an integral part of the railway and vital in keeping trains moving safely. Their apparent complexity can be one of the reasons why signals often get left off layouts, but they are an essential detail that every layout needs.
That’s where this guide will help. Of course, a subject such as signalling deserves its own book and there have been some excellent ones produced over the years. We don’t have the space to get into ‘calling on’ or ground signals but, over the next eight pages, we’ll explore some of the common terms and key positions so that you’ll feel confident placing them against your track layout. If you want to know more about signalling, see the Further Reading panel on p37.
Now, we’ve been given the ‘line clear’ – let’s proceed…
What is a signal?
In its simplest sense, a signal tells train drivers when they can go and when they have to stop. They are tied into systems that are ultimately designed to prevent trains from crashing into each other.
The railway is divided into blocks and, traditionally, each block was controlled by a signal box. That block allowed additional safety systems to evolve, such as staff and ticket, where a train cannot proceed until it is in possession of a ‘token’.
Then there’s BR’S Automatic Warning System and its forerunner, the GWR’S Automatic Train Control, where drivers are warned of signals at danger by a shoe under the train making contact with an energised ramp in the track, sounding audible bells and buzzers in the cab.
We’ll look at blocks again later.
There are two main signal variants: semaphore and colour aspect. Semaphore signals date from the very earliest days of the railway. Essentially, the position of the arm dictates whether the train can proceed or whether it must stop.
Colour aspect signals began to appear on main lines in the 1930s and were widely adopted by BR in the 1950s/1960s. They are the most common signal type today and most closely related to the road traffic light. Some main lines still retain their semaphores but Network Rail is working hard to replace them, so their days are numbered. Britain’s preserved railway network is arguably the best place to enjoy semaphore signals in action..
Below: Colour light signals are not just confined to the modern era. They began to appear on ‘Big Four’ lines in the 1930s and could be found on BR metals in the 1950s, including the relative railway backwater of South Lynn, on the Midland & Great Northern Joint system.
Below: A Class 105 DMU accelerates under an impressive gantry of distant signals spanning the East Coast Main Line at Finsbury Park in 1973.
Right: Even Britain’s smaller railways would invest in some pretty impressive signalling infrastructure. Lynton station, on the narrow gauge Lynton & Barnstaple Railway, is protected by these impressive bracket signals, controlling access to and from the main and bay platforms.