When I was much younger, I studied railway signalling and, through the kindness of a number of signalmen, I became a regular visitor at various signal boxes in the West Midlands. One of my favourites was Tipton, on the Stour Valley Line between Birmingham New Street and Wolverhampton. Under supervision, I worked this box on countless occasions. In May 1961, I made a simplified copy of the signalbox diagram, which is shown above. Larger version of the diagram.
The mechanical box was situated on a double track main line using Absolute Block signalling, controlling a busy road crossing with mechanically worked gates. The next box to the left (the Birmingham direction) was Watery Lane (which survives, but with a diminished role). The next box to the right (the Wolverhampton direction) was Bloomfield Junction. The line diverging bottom right joined the South Stafford Line at Wednesbury, giving access to the marshalling yard at Bescot, Walsall and beyond. The adjacent box was Tipton Curve Junction, where there was a branch to Bloomfield Junction, forming the 'Tipton Triangle'. The signalling was semaphore in 1961 and there was only one track circuit. A few years later, the branch was abandoned, a power signal box at Wolverhampton abolished all the mechanical signalboxes and the line was electrified. Tipton box survived for some years to supervise the road crossing, which was provided with lifting barriers. The crossing remains but is now supervised remotely from Watery Lane and all trace of the Tipton box is gone.
The box was a standard London and North Western Railway design, with a brick base. The lever frame was the earlier Webb design with the massive interlocking in the ground floor 'locking room'. Above the colour-coded levers on the operating floor was a block shelf carrying three Fletcher pattern double-needle block instruments plus sundry lamp repeaters.
Most movements were through trains on the main line, some of which called at the station (adjacent to crossover 19). Down trains required levers 3, 4 and the distant signal 2. There was block control on lever 4, requiring 'Line Clear' from Bloomfield Junction before clearance was possible. Up trains required 34, 33 and wire-operated distant signal 35, mounted on Bloomfield Junction's up starting signal, the 'four-armer'. Provided this distant signal had been correctly cleared (which could be tricky in summer when the wire expanded, unless the "slack adjuster" was correctly set), motor-worked distant 35B cleared automatically.
There was no Block Control on signal 33, which was termed a 'free signal'. Entrance to the sidings on the down side required lever 14 which controlled a set of points in the down main and two sets of trap points. Lever 15 selected between Siding 1 (the "front road") and Siding 2 (the "back road"). As was common, ground signal 13 controlled access to the main line from both sidings. Authority to back from the down main into either siding was by a handsignal from the box. Movements through the crossover, 19, were also controlled by handsignal. The branch line was accessed via facing points 21, provided with a facing point lock and locking bar, lever 21. Beyond the junction, there was an unusual locking or clearance bar, lever 18, with spring-controlled catch points beyond. A down train onto the branch required signals 5, 6 and 7. The trailing connection from the branch was lever 22, protected by signal 30. There was only a fixed distant signal coming off the branch: this was mounted on Tipton Curve Junction's "four-armer". Annett's Key 'A' released a sidings ground frame, but I never saw this used.
Then there were the level crossing gates, just outside the box. It was a skew crossing where two gates moved first, then the other two. Instead of the more common "ship's wheel", the gates were controlled by a "mangle wheel" with a greater reduction ratio requiring around 14 turns to complete the movement. It was quite difficult to get the gates swinging but, once they were moving, it was even harder to stop them. In those days, there were no flashing lights to control the traffic, you just had to wait as long as you dared then try to force the traffic to stop. But, of course, no motorist wants to be first in the queue, so they would tailgate or dash onto the crossing to try to prevent the gates closing in front of them. Minor accidents were common.
At that time, the majority of trains were still steam-hauled, although many of the locals were diesel multiple units and some main-line diesels were appearing. I feel very privileged that I saw the railway as it was, before it was all swept away. The movements I witnessed belonged to a different era. You can find more on this signal box here.
