Great Cockcrow Miniature Railway

Great Cockcrow miniature railway has given us permission to port information over from their site. They are a great miniature railway with a fantastic signalling system, It is also worth checking out their signalling simulators one for each of the three signal boxes. Click here to visit their website.


The line is fully signalled with 3 signal boxes and 1 gate box to prototypical British signalling based on mid-1950’s practice. With the exception of the signals, which are scale models, the signalling system is constructed from full-size equipment recovered when it became redundant. The line is signalled from three signal boxes at Hardwick (controlling the main terminus), at Cockcrow Hill (where some trains terminate) and at Everglades Junction which all trains pass at least twice. The signal boxes at Hardwick and Everglades Junction utilise Westinghouse style L all-electric miniature lever frames, whilst Cockcrow Hill has a 16-lever “Stevens Knee” frame with electrical locking.


Hardwick is a 23-lever frame that was part of the original Crewe South Junction (which had 227 levers and was in use from 1939 until 1986) and was installed and commissioned in 1993. The Signal Box is equipped as far as possible as an old LMS Signal Box would have looked in around the 1950’s with an illuminated diagram made of timber with a hand-painted track layout, and two red lamps at the extremities of each track circuit. In following basic LMS practice, the point operating levers have notched quadrants at the ‘B’ and ‘D’ positions for point indication locking and the signals have quadrant notches at the ‘B’ position for back locking. Of course, being an all-electric locking frame ‘A’ and ‘E’locks and quadrants are provided on all levers.

At Hardwick, following LMS tradition, 1 lever is provided for a signal no matter how many routes are available from that signal. To aid the signalman, above the lever is provided with an indication that shows what route (or destination) is presently set for that signal. The pull plates are in front of the lever on a shelf that is standard for all ‘L’ frames (presently with temporary labels, but the intention is to replace them with brass pull plates as originally provided). The signal indications simply show red when the signal is at danger and white when the signal is “off”. Although the Railway is completely track circuited, absolute block working is in force to the next Signal Box using Midland Railway type instruments (circa 1914) will full track circuit controls.

Everglades Junction

Everglades Junction is set out as a Southern Railway Signal Box as it would have been around the 1950’s. The Westinghouse ‘L’ frame is of 31 levers and came from South Croydon when the Three Bridges re-signalling scheme was introduced in April 1984. As the frame was installed in 1953 it had quite a short life on BR – even so, it is now 50+ years old. The frame came complete and is installed as per the original SR standards in 1980 and expanded and re-wired in 1991. It controls 3 and 4 aspect signalling, and again following SR practice, the aspects on the signals are repeated on the frame including junction indicators. One signal lever controls all possible routes from that signal, with in addition a separate lever for a “warning” route. Again following SR practice, there are no indication quadrants, the lever position and detection being in the circuit for the release of the signal lever. ‘Free’

indications are also shown above the signal levers.

A standard SR illuminated diagram is provided. Block Working to adjacent Signal Boxes is via Southern Railway Standard instruments (circa 1920’s) with full track circuit controls. In true SR practice, the “tapper” for the Block Bells is not part of the bell but mounted separately using brass plungers.

There is also a Train Describer using a VDU display with automatic code ‘set up’ and automatic ‘code change’ to help the signalmen keep track of the trains, and to also keep a count of the number of trains run over the system in any one day.

Cockcrow Hill

Cockcrow Hill Signal Box is a 16 lever Stevens “Knee Frame” with electrical locking and was commissioned in May 2001 replacing an LMS 1943 tappet frame after the layout at Cockcrow Hill Station was completely re-modelled. 12 levers are fitted with combined lever locks and circuit controllers and the other 4 levers have circuit controllers only.

The Railway Signal Co manufactured this frame and it was originally installed at Waterloo Station on the “Waterloo and City” line and is thought to be over 80 years old.

Relay Rooms

All Signal Boxes have Relay Rooms containing the necessary relay racks, power supplies and cable termination racks. These utilise standard BR 930 Spec series relays which plug into plugboards. The different types of relays have varying numbers of contacts and include timing and delay functions.

Location Cupboards

Full-size locations are situated as required around the Railway and contain Track feeds and relays. All Locations are fed with 110 volts 50 Hz and have heaters and lighting within the location and are wired to BR Standards (circa 1992) and standard BR type cables connect the location to the trackside equipment via 2BA sliding links.

Track Circuits

Track circuits are fed via a Transformer/Rectifier (ex Reed Amplifier Power Supply Units) with an adjustable 20-ohm resistor and use a 12v BR 930 Spec. relay with a minimum pick-up of 6.3 – 7.1v. (Reed followers are very useful!) The rail is bonded at the joints and we make our own insulated joints.

Point Machines

Point machines are made up from 12v Ford Escort Wiper Motors with microswitch detection circuits on machine operated and some spring-operated points. The insulated front stretcher is made from polycarbonate strip and the point machines have an integral FPL.


Colour light signals are made up from SGE/WBS/Tyers block shelf indicators stacked as necessary, fitted with polycarbonate coloured lenses and aluminium display boards. The bulbs are 12v. 2.4w although we are trialling an LED version. Junction Indicators are 12v individual lamps mounted as required.

Semaphore signals (both upper and lower quadrant) are solenoid worked with a constantly rated 24v. 12w. Coil, sealed for out-door use. Semaphore signals are electrically lit either using 12v. 1.2w. Lamps or as we convert them LED clusters switched on from the controlling signal box. All Signals outside the Hardwick compound are plug coupled and are removed at the end of the running day.


There are Signal Post Telephones at all controlled signals with an electronic PABX for other telephones. We also have handheld radios for all operational staff.


The signalling system is extremely reliable and failures are extremely rare. (Approx. 2/3 incidents a season) All relays are BRB 930/960 specification and live in heated Relay Rooms and locations. Considering that the power is turned off from Sunday evening to the following Sunday morning in the summer, and is off during the winter months from November until the end of April – when switched on, it always works.

We get the very occasional point problems (stones in blades!) and sometimes a broken track circuit bond caused by someone walking on the track and accidentally kicking the bond (a problem with miniature railways!)

Design and Construction

All design and construction are done in-house by the S&T department with the relay room and signal box circuits being hand-drawn in pencil on A3 size paper. The location diagrams are drawn using a computer and AutoCAD on A4 size drawings.

The S & T department, as you would expect, is mainly made up of Institution of Railway Signal Engineers’ members and gives the opportunity to all to continue to increase their professional development!

The Railway is, in fact, a wonderful training aid for all S & T Engineers (as well as operating colleagues) and has been used by other organisations such as the HMRI and IRO!