Crossbar and Board signals
Many of the earliest railway signals, from the 1830s, were simple wooden boards or discs mounted on a post, which could be revolved to show two indications. If the board faced the driver it indicated stop but if it was parallel to the line (and thus effectively not visible to a driver) it indicated clear.
Signals of this type lacked a few essential features of later signalling, such as giving a positive clear indication and automatically returning to danger in the event of failure, and were replaced by semaphore signals in the first step towards the kind of signals we are familiar with today.
However, the basic principle of revolving boards lived on in a few locations. At least two railway companies adopted these signals for special purposes that weren’t actually much different to their original use.
An interesting feature of the survival of this type of signal was the essential need to bring trains to a stand clear of points, level crossings etc., which was a feature of 1850s signalling, rather than to permit movements right up to the signal concerned. How this might be achieved in a thick pea-soup fog has never been documented, right from the first days of signalling through to the final abandonment of the use of such signals in the 1980s.
Midland Railway crossbar signal
The Midland Railway used their crossbar signal within sidings to indicate when shunting could take place. A typical situation would be a location where a goods branch joined a bank of sidings within a goods yard. The board would be turned to face shunting movements to indicate when shunting movements must not be made, owing to the approach of a train on the branch. The last known example of this type survived at Bournville, by Cadbury’s chocolate factory, into the late 1970s.
Another function of such a signal was to protect blasting operations at quarries. Again, the board would be turned to face shunting movements in sidings to indicate that all shunts must stop while blasting took place. One such existed at Tunstead, Derbyshire, into the 1960s.
The example illustrated here was preserved in the Bass brewery Museum at Burton but its fate is unknown as the museum has closed. The arm should be painted red to be correct. This example was once to be found on the network of railways serving the breweries in Burton, which were signalled by the Midland Railway. This particular signal was never worked directly from a signal box – the handle that revolves the board is at the foot of the post, just the way such signals were worked in the 1830s.
North Eastern Railway board signal
The North Eastern Railway continued to use board signals at un-interlocked level crossings. Like the Midland signals described above, this type of signal survived through its ability to show the same indication in both directions.
The example illustrated here was at Ainderby level crossing on a single line section of the branch between Northallerton and Hawes. The signal was simply turned parallel with the line once the gates were closed to the road, operated by the handle on the post.
Another example survived into the 1980s worked from the quaintly named Cherry Tree signal box at Beverley. Here, a siding ran across a level crossing alongside the double track main line. Just like the Midland signals above, it indicated when shunting could not take place.