Inside Scotland's main line railway signal boxes still using Victorian-era technology

Network Rail needs historic equipment for spares when signal boxes close so it can’t go to museums

It is a world of Victorian-era technology that would be familiar to Charles Dickens, but is still in use across the Scottish rail network - and remains out of the clutches of museums because the equipment is needed for spare parts.

While trains on the country’s busiest lines have been controlled by traffic-light style signals for up to a century, a much older system involving large metal levers, semaphore signals and Morse Code-like “bell codes” remains in use on several lines outwith the Central Belt.

Signal boxes dating back 150 years control sections of single track lines - and have been given a further stay of execution under Network Rail Scotland’s (NRS) latest plans, which will see some continuing in use for at another two decades and a couple of them indefinitely.

But as they are gradually phased out, rail museums such as the one which forms part of the acclaimed Glasgow Central Station behind-the-scenes tours will have to wait a little longer to get their hands on their historic equipment because it is still being recycled for spare parts.

Lynsey Hunter, who is charge of signalling for NRS, said despite its age the system remained fit for purpose on lesser-used routes and would only be replaced as part of wider upgrading, to reduce overall costs and minimise disruption.

Signaller Gordon McCabe pulling a signal lever in Stanley Junction signal box. (Photo by Lisa Ferguson/The Scotsman)

A world apart from the large computerised signalling centres in Glasgow and Edinburgh, mechanical signal boxes involve signallers pulling waist-high levers connected by wires to raise or lower enamelled rectangular metal signal arms - which themselves could be 100 years old.

The signallers normally communicate with each other not by phone, which had not been invented when such railway signalling was developed, but by tapping out a sequence of Morse-like codes, which are acknowledged with a series of bells.

As Simon Bradley put it in his book The Railways: “Mechanical signs with moving parts no longer play much part in everyday life, so there is something marvellous about the survival of this Victorian technology into its third century.” The Scotsman was given rare access to see such traditional signalling in action, which is of a type similar that featured in Dickens’ 1866 story The Signal-Man.

At Stanley Junction signal box, between Perth and Dunkeld, Gordon McCabe is one of four signallers working solo 12-hour shifts where the line north to Inverness narrows from double to single track.

Network Rail Scotland regional asset manager (signalling) Lynsey Hunter said semaphore signalling was still for for purpose on lesser-used lines. (Photo by Lisa Ferguson/The Scotsman)

Although built as recently as 1961, it houses similar technology to that in Scotland’s oldest working signal box, at Hilton Junction, south of Perth, which was opened in 1873 and is due to be closed in five years’ time as part of a new signalling system around the city.

Mr McCabe said: “When people think about railway signalling, they think of people sitting at a desk. My family are amazed that I still pull big levers.”

The signaller may not see anyone during his shifts other than the train drivers, whom he acknowledges to “check they are not under any distress”.

The job also involves casting his eye along the train as it passes for anything amiss, such as an open door, and, crucially, to check there is a red tail lamp on the rear carriage, which shows part of the train has not detached since the last signal box.

Mr McCabe said despite only about 20 trains passing the signal box during a regular shift, it could suddenly get much busier.

He said: “There’s a lot of mental concentration involved. There might be a period in the day you feel nothing’s happening, but things can change in an instant.”

Mr McCabe said late-running trains, people phoning to request use of a level crossing, engineers on the line and equipment faults could mean “everything snowballs and escalates”.

He said: “You’ve got to have that composure and focus to be calm and able to methodically work your way through it.”

The job also remains largely physical, from pulling levers controlling the signals and the points switching trains between tracks to the constant adjustment of the tension in the signal wires. Mr McCabe said: “Depending on whether it’s hot or cold, I might have to tighten or slacken the cable - it might be warm in the morning and cold in the afternoon.”

The 41-year-old joined the railways in 2020 after years as a retail manager, prompted by the Covid lockdowns to change career.

He said: “I’ve got a lot of friends on the railway and I was interested in working there when I was younger, but never had the time to apply.” Those on his training course ranged from people their early 20s to their 70s.

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There are still 47 mechanical signal boxes in Scotland - the largest being in Stirling - along with ten more modern centres.

Lynsey Hunter, regional asset manager (signalling) for Network Rail Scotland, said previous plans to centralise signalling in Edinburgh and Glasgow had been changed.

She said: “The idea now is that rather than go to two main hubs, to vastly reduce the number of signal boxes to about ten-12 over about the next 20 years.”

A semaphore signal at Dunkeld Station believed to be around 100 years old. (Photo by Lisa Ferguson/The Scotsman)

However, she said some junctions would always have mechanical signal boxes, such as at Fouldubs, on a branch line to Grangemouth port, and Fort William, which is between two radio signalling areas.

Ms Hunter said: “To close a signal box is very expensive. So to spend money efficiently, we only make major changes when we are doing other work, such as extending passing loops on single-track lines or electrifying a route.

Stanley Junction signal box was built in 1961 but houses signalling equipment of a type developed in the Victorian era. (Photo by Lisa Ferguson/The Scotsman)

"Our railway forefathers knew what they were doing and designed a system that was suitable for the capacity at the time. As we can still safely sustain the equipment which allows for the onward safe travel of trains, it will remain appropriate for a good time to come. But ultimately, it may become a point where the kit cannot be safely maintained and that is also when we would have to act."