The Spinney Light Railway

Overview of the Signalling

Old Oak Home Signal

The railway is fully signalled and the majority of the signals are 1/6th full size LNWR lower quadrant signals, reflecting Joseph Ballantine Dykes interest in that railway.

1/6th size is used rather the 1/8th size you would expect from the gauge of the track because this allows more robust, taller signal posts with larger arms yet retaining the correct proportions.

The semaphore signals are operated by 12 Volt electromagnets which are energised to clear the signal in the same way as the original Crewe power signalling system.

A number of colour light signals are also used. There is a colour light intermediate block signal with a colour light distant on the down line between Spinney and Bay Tree; these are commercially available signals using LED lamps. The two signals just before each tunnel are automatic, worked by the track circuits. The signal at the tunnel exit can show a route "feather". Apart from the LED signals just mentioned, the colour light signals use lamps and lenses designed for use as block shelf indications in full size signalboxes. Two ground position light signals are used showing a red and white for stop and two diagonal whites for proceed. Finally, three banner repeaters give early indications of signals in the tunnel area.

Dingly P1 Starter: Left to right section signal, headshunt, downsidings

Interlocking between points and signals is provided in all four signalboxes. On the main running lines there is also track circuit interlocking. Track circuits are DC, using full size signalling relays but use line rather than track relays to allow an increased rail voltage for improved shunting characteristics.

Points are operated by 12 Volt motors, either windscreen wiper motors or the motors used to raise or lower windows in modern cars. The main line facing points are checked secure in either direction by separate detection microswitches and the motors are isolated whilst the track circuit across the point is occupied so preventing them being moved under a train.

Block instruments are used to establish if the line is clear to send a train. Those who recall the railways of Britain forty years and more ago will have their memories revived by the familiar "ting-ting" as the block bells carry their message between boxes.

A small automatic telephone exchange is provided to allow direct communication between signalboxes and key locations on the railway

Signalling Inventory

Stop Signals Distant Signals Shunt Signals Colour Light Signals Banner Signals Call On Signals Levers Track Circuits Controlled Points
Bay Tree 8 3 3 - - 1 19 7 3
Dingly 7 1 fix 11 - - - 24 2 8
Old Oak 7 1 fix 1 - - 1 12 5 3
Spinney 11 3 1 5 3 - 19 18 4
Total 33 8 16 5 3 2 74 32 18