The signalling on BHLR (Beer Heights Light Railway) which is located at Pecorama in the delightful village of Beer in sunny Devon has been developed over a number of years provides a fully automated 'fail safe' system for the movements of trains around the 1.5 mile circuit.
Trains depart from Much Natter, were the Station Master is required to initiate the
departure from either of the 3 platforms using a miniture 3 lever frame and the departure buttons. Once initiated the train will be automatically routed aound
the system back to Much Natter, were the Station Master will accept the arrival again using the miniture lever frame.
Service trains depart from the 'Departure' platform and can route either via Little Moore(GWR) or straight to Tunnel East(SR), the 'Bay' platform at Much Natter is primarily used to store locomotives when more than 2 locomotives are in use.
A number of driver operated 'Plungers' are sited on various signals to allow for shunting, and other deviations from the main route:
- Little Moore Bay Platform used for shuttle service to Wildway Branch
- Non-Stop Allows for trains to go back to Tunnel East instead of Much Natter
- Wildway Branch Desination of the Shuttle service
- Quarry Siding Where visiting locos arrive and depart(By Road)
- Depot Engine shed and carriage sidings
There are 2 types of Signals:
- Semaphore: These are based on Great Western Railway (GWR) lower quadrant signals, where the arm drops to show proceed.
- Colour Light: These are based on the British Rail (BR) generic 2 aspect signal
There are 2 types of points:
- Powered: These are used by the interlockings to 'divert' trains at junctions.
- Spring: These 'divert' trains in a fixed direction, and when 'trailed' are 'sprung' by the train wheels.
The signalling is split into 3 relay based fail-safe interlockings:
This is the main station from were sevice trains depart and return to.
There are 3 platforms
(1) Arrivals, were trips terminate.
(2) Departures, were trips start from
(3) Bay, mainly used for locomotives to lay over between trips
There is a turntable linking the Arrivals and Departure platforms so locomotives can be turned between trips.
This is were the depot is located, which has the engine and carriage sheds.
There are two platforms at Little Moore, 'White Falls Halt' which is used as the destination platform for the Wildway shuttle service, and 'Little Moore Bay', which is the starting point
for the Wildway shuttle service.
This is the 'scenic ' portion the the railways which is accessed via the tunnel under the car park.
The 'Wildway' branch line, 'Deepwater' loop; and 'Quarry Siding'
The loop at Deepwater is used to allow trains to pass, and take on water if required.
The Quarry siding is were visiting loco's arrive and depart using the 'lift' to transition from road vehicles to the track.
The prime objective of the signalling system is to safely signal trains around the circuit. To do this the presence of a train or part of a train in each section of track is needed, this is acheived using 'DC Track Circuits' of a similar design to the prototype used on Network Rail. To achieve this the track on the running lines is devided up into sections using insulated 'fishplates' on one rail. Within each interlocking area the other rail is designated the common rail. A low dc voltage is fed to the isolated rail at on end of the section via a load resistor, the other end of the section is then connected to a Track Relay which is energised by the voltage, when the wheels of a train enter the section, they short the voltage and the track realy de-energises indicating the presense of the train.
When a route is set its HOLD locking relay is de-energied this then prevents other routes from using the same section(s) of track, when the train has fully cleared the section, the HOLD relay is energised freeing the section for use by another train.
During normal running the next route is set when the train passes the previous signal and entes the next section.
At convergent and divergent points on the circuit First Come First Served relays are used to control the flow and prevent deadlock.
The tunnel is which has a bi-directional single line through it is protected by SPAD circuits, which set off a audible and visual alarm if a train passes the protecting signal at danger.
The Signalling system is monitored by 2 'Raspberry Pi' computers which are connected various relays in the three Interlockings. These inputs are logged in daily files which can be used to diagnose anomilies.
