West Somerset Railway Signalling
by Kevin Weston
History of the line
The original West Somerset Railway Company was incorporated by an Act of Parliament on 17th August 1857 and was authorised to construct a line from a junction with the Bristol and Exeter Railway (B&E) at Norton Fitzwarren to the harbour at Watchet. Construction started at the site of Crowcombe Heathfield station on Thursday 7th April 1859 and the line was opened on Monday 31st March 1862. It was built to the broad gauge of 7ft ¼in and operated by the B&E from the start. The Minehead railway began work in 1871 to build a line from Watchet to Minehead, a distance of 81/2 miles. From the opening day on Thursday 16th July 1874, the B&E operated the line as a through route from Taunton. The B&E were taken over by the Great Western Railway (GWR) on 1st January 1876 (some sources give the date as 1st August 1876) who converted the branch to standard gauge over the weekend of 28-30th October 1882.
Although the branch was now operated by the GWR, it still remained the property of the two independent companies. The GWR took over the Minehead Railway on 1st July 1897 and the West Somerset Railway on the 1st January 1922. The GWR carried out major engineering works in the 1930’s, including the upgrading of the single track to double track double track between Norton Fitzwarren – Bishops Lydeard and Dunster – Minehead. Two new crossing loops were installed at Leigh Bridge and Kentsford.
Nationalisation in 1948 originally saw little change to the branch. In the 1950’s, a number of the wooden post signals were replaced with tubular steel posts. During the 1960’s there were reductions to the signalling; the crossing loops and signal boxes at Crowcombe, Leigh Bridge and Kentsford were removed. The double track section from Dunster was converted to two single-track sections and, with the closure of Minehead signal box, there was no connection between them at the terminus. There were further economies in 1970 to try and make the branch profitable; the double track section to Bishops Lydeard was removed, together with the closure of Bishops Lydeard and Norton Fitzwarren signal boxes. This section was now worked as one single line from Silk Mill Crossing signal box to Williton. The three remaining signal boxes had level crossings, which is why they were not closed. Even with these reductions, the branch still required the three signal boxes to be manned for two shifts each, and four isolated level crossings, each manned by a crossing keeper. Including the train crew of a driver and guard, it required 9 people to operate a train and it was no surprise that passenger traffic was withdrawn on 4th January 1971.
Re-opening in private ownership
The present West Somerset Railway Company reopened the line in stages, starting with Minehead to Blue Anchor on 28th March 1976 and to Williton by the end of the year. Full services to Bishops Lydeard commenced in 1979.
The WSR operates from the Railtrack boundary at Norton Fitzwarren (milepost 1651/4) and is single line throughout, a total of 221/2 miles. Regular passenger trains operate between Minehead and Bishops Lydeard, 3 miles from Norton. On gala days, special trains run over the Norton section; with no run-round facilities at the Railtrack boundary, the train operates with a locomotive at each end. There are intermediate crossing loops at Bishops Lydeard, Crowcombe Heathfield, Williton and Blue Anchor. At each crossing loop is a signal box, controlling entry to the block sections. Crowcombe can “switch out” when not required for crossing trains, the block section then becomes Williton to Bishops Lydeard.
The WSR uses three systems for control of the single line sections. One Train Working (OTW), with a wooden train staff, is used on the Norton section; when WSR trains traverse this section, they only travel as far as the Railtrack boundary and then return. Through trains from Railtrack require the staff to be conveyed by road to Taunton station before the train can enter the section. The three sections between Bishops Lydeard and Blue Anchor use Train Staff and Ticket (TST). When Crowcombe is switched out, a long section staff is used between Williton and Bishops Lydeard. The Minehead – Blue Anchor section uses Electric Key Token (EKT). Communication between signal boxes for block working is by British Telecomm telephone, except the Minehead – Blue Anchor section, which is by block bell using a system of bell codes.
The first recorded signalling on the line is dated 22nd February 1875, with the inspection of the signal box at Williton by the Railway Inspectorate. It is of a B&E design constructed in brick and is only one of two still surviving. The other, at Weston-Super-Mare, dates from 1866 and has been disused for many years. Williton was an original crossing loop, although the actual signalling is uncertain, it is possible that GWR style “Disc and Crossbar” signals were used. The first recorded lever frame used here was a GWR pattern of 16 levers with Stud locking. This would not be the original, as Stud frames date from 1892. The original frame was probably made by Saxby and Farmer, who manufactured most of the signalling for the B&E. The Stud frame was replaced in June 1937 with the current 5-bar vertical tappet frame of 25 levers.
Most of the layout in use today dates from 1937, and consists of a crossing loop and the old goods yard at the Minehead end of the station. This yard is now the base for several groups, including the Diesel and Electric Preservation Group, who operate mainline diesels over the WSR. The only major alteration was in March 1968 when British Rail shortened the loop at the Taunton end by 50 yards to rebuild a river bridge. The semaphore signals are British Rail Western Region (BRWR) pattern installed in the 1950s to replace the GWR signals that had wooden posts and signal arms. The WSR added a number of new shunting signals during the 1980s and some of the signals have had their oil lamps replaced with electric lights, an idea that is used on several private railways as well as Railtrack. We use 24 volt, 36-watt lamps, fed at 12 volts which produces a low light that matches the old oil lamps. Where necessary, relays are wired in the circuit in to detect that a lamp is alight. All new semaphore signals on the railway have electric lights and as time permits, all the older ones will also be fitted. The level crossing is protected by gates, which are worked by hand, although there is an interlocking lever to release the signals when the gates are locked across the road. Age has taken its toll on the signal box, as proved when the floor of the locking room collapsed during the summer of 1998. Work to rebuild the floor started in November with the aim of completion in time for the Christmas services. This had not proved easy as a water pipe, which predates the signal box, was discovered under the floor. A new foundation had to be built to support the floor timbers; the originals were resting on built up ground and the water pipe, which, according to a structural engineer, is no longer strong enough to take any weight. The winter of 1998/99 will also saw some alterations to the layout. A connection to the Minehead end of the repair shed and two shunting signals were added.
Blue Anchor is the other signal box on the branch that retains most of its original equipment. It is of brick construction and the opening date is generally given as 1904. The layout is simple, a crossing loop with a siding at the Minehead end. Three camping coaches are parked on the siding, although the point was disconnected when the line reopened. Some of the equipment in use dates from the opening of the signal box. There is a road crossing at the Minehead end, protected by wooden gates operated by a wheel in the signal box. This is the last set of original GWR gates in use; all the others on Railtrack have been converted to barriers. It is known that the crossing was rebuilt in 1955, we have the drawings for this work and they indicate that the operating mechanism was overhauled but not altered. The road approaching the crossing from the sea front is on a sharp bend and, despite the 30 miles per hour speed limit; some car drivers still come around the bend too fast and find the gates across the road. The gates are hit at least once a year and the drivers have some original excuses. One of the best was on a summer evening; a train from Minehead was in the process of a run-round move when a car hit the gates, the driver complained that the accident would not have happened if we did not run trains in the evenings. The point at this end of the loop is operated by the original rodding, although it is possible that the point was moved about 20 yards in 1934. This was the date that the loop was lengthened at the Williton end. The Minehead end point retains its original fouling bar for the FPL; the one at the Williton end of the loop was converted to motor operation in September 1995, using a reconditioned Westinghouse Style M3A machine with track circuit locking. Some of the volunteers had complained about the use of this modern equipment, but they have been reminded that this “modern equipment”, based on a 1930’s design, is older that some of the steam engines they drive.
All the signals are BRWR design, erected around the same time as those at Williton. When the branch closed in 1971, all the internal equipment, apart from the lever frame, was removed. This equipment had to be replaced before the signal box could be reopened. The frame has 17 levers with Stud locking and is dated 1903, indicating that it was constructed in Reading Signal Works before the signal box was built. It is believed that this frame is the oldest of its type still in use in the signal box for which it was designed. Railtrack has only one original Stud frame still in use, while several of the other private railways have used reconditioned Stud frames. Token working to Minehead was introduced in 1990 when the signal box there was opened. The WSR has no signalling cable between the two signal boxes; the token operates over a dedicated British Telecom line using a system of ac frequency signals. Six frequencies are required to operate the system, which must ensure that only one token can be removed at any time. While the signal box and station may give the appearance of a country station in the 1950’s, it is an interesting mix of equipment, the modern electronic system for the token is working along side mechanical interlocking designed nearly a hundred years ago.
Not all the siding connections are controlled by a signal box but the Railway Inspectorate still require that all facing points on a passenger line are fitted with a Facing Point Lock. Within the control of a signal box, the FPL is either locked electrically through the lever lock or by a mechanical fouling bar. In a block section, some other means is required to interlock the point with the train staff. The normal method of operation is to provide a small ground level lever frame to operate the points. The levers are locked in the normal position and can only be released by a key attached to the train staff. The key is retained in the lock while the points are operated and can only be removed when the point levers are returned to normal. At the present time there are two intermediate ground frames, one at Dunster and one at Washford.
The signalling on the railway remained relatively unchanged from the day of reopening until 1990. There were some minor alterations at Williton over the years but no major work. 1977 did see a unique logistics operation. The signal box that controlled Dunster West crossing until BR closed the line had to be removed as one of the conditions required to convert the crossing to an “open” type. This was to improve visibility to both road and rail traffic. It was of an all-wooden construction and, rather than demolish it, the WSR wanted to remove it for use elsewhere. It was decided to move it to Minehead as a replacement for the signal box that BR demolished in 1966. The structure was fairly strong and to save time, it was transferred in one piece on a rail wagon. This was not the first time that the box had been moved, originally it was constructed for use elsewhere and was moved to Dunster in 1933 when the double track was installed.
Minehead was the first “new” signal box to be opened by the WSR. The station has two platforms, and, before the introduction of token working, two wooden train staffs controlled the single line, one staff relating to each platform. A ground frame controlled the points giving access to each platform. Both train staffs had to be placed into locks on the ground frame to release the point levers. When the points were set for a platform, the appropriate train staff could be removed from it’s lock, only one staff could be removed at a time.
During the 1980s, there was an increase in the number of people attending the nearby sea front holiday camp. Most of the residents arrived by car and the only road access was through the town. To relieve the congestion, Somerset County Council wished to construct a new road from the village of Alcombe to the sea front. The route was over Dunster marsh and across the railway about ¼ mile from the station. The road could not go under the railway as there was a risk of flooding, while an over-bridge would be too heavy for the marshy ground. The only solution was a level crossing. The crossing would be about 100 yards from the signal box and to reduce costs, it would be an automatic barrier type and not controlled directly from the signal box. It was designed and installed by a contract company and paid for by the Council. At the same time, the WSR began design work on the signalling for the station. As the crossing is located within the station limits of the signal box, some interlocking was required to ensure the safe passage of trains. Trains in the up direction operate the crossing by the occupation of track circuits; there is no direct interlocking with the signals. In the down direction there is a protecting signal and the crossing will not operate until the signalman has set a route into the station, although the signal will not show a proceed aspect until the barriers are down and the road lights are operating. The Railway Inspectorate required that this signal was to be a colour light. It shows indications for six routes in addition to the flashing white light for the crossing. Westinghouse signal motors operate the semaphore signals at the Dunster end. Internally, the signal box has a 27-lever GWR tappet frame, part of a larger 99-lever frame that was recovered from Westbury South in September 1978. With some of the equipment operated electrically, a number of the levers have short handles, this is to indicate to the signalman that the equipment is electrically operated and a heavy pull is not required. The signalling was commissioned in three separate stages, with the level crossing in full working order for about a year before the road was completed.
Two views showing the mechanical interlocking between the levers in Minehead boxes. First, the cam plates worked by the levers impart vertical travel into the numbered bars which have notches cut in them for the tappets to engage against (second):
The present Minehead station retains the two platforms, a Main and a Bay, although only the Main has run-round facilities. Two carriage sidings are located next to the Bay while opposite the main platform there is a three-road locomotive shed and workshop. There is also a siding for the coach workshop.
After Minehead was commissioned, the railway was now capable of operating one train every hour to Williton, however, the long block section to Bishops Lydeard restricted the service on the south end of the line to a train every two hours. A normal daily timetable requires only two trains, operating a total of four services each way. The timetable was arranged so that all trains met at Williton. Galas were a problem; very few extra trains could run to Bishops Lydeard and most would only run between Minehead and Williton. To increase line capacity, an extra block post was required. Two crossing loops had existed on this section and in 1992 it was decided to reinstate the loop at Crowcombe Heathfield station.
Crowcombe is at the summit of a climb from both Williton and Bishops Lydeard and in places, the gradient can be 1 in 86. This had always slowed trains and to reinstate the block post would double line capacity on this section. The opening date of the original signal box is uncertain, although it is likely that it was in connection with the conversion of the line to standard gauge in 1882. It contained a 16-lever Stud locking frame up to closure in 1967. This would not have been the original frame if the opening date were correct, as it predates Stud frames by ten years. There is also one source that gives the frame date as new in 1928, The last Stud frame was made in 1908, and so either the date in incorrect or the frame was constructed of reconditioned parts. After closure, the building was completely demolished. To reinstate the crossing loop and signal box required a “new” structure. It was decided to use the original foundations on the down platform. The top portion came from Ebbw Vale Sidings South signal box in south Wales, and is located on a new brick locking room. The lever frame is now in it’s third location. It was first used at Marsh Junction in Bristol and was moved to Frome North in 1970. In 1984, Frome North closed and the frame was purchased by the WSR. The frame has tappet locking for 34 levers but only 29 are required for the new layout at Crowcombe. Some of the signals have been designed in the style of the originals, which had square section posts and wooden arms. The signal at the Williton end of the down platform is a good example; two others are at the south end. The railway has cheated with the “wooden” posts; good quality timber was too expensive, therefore to reduce costs, concrete was used. The new layout allows the signal box to “switch out” when not required. Three train staffs are provided, two for the short sections either side of Crowcombe and one for the section when the box is switched out. All three are interlocked so that only the two “short” staffs or the single “long” staff can be in use at any time. The staffs are also interlocked with the lever frame so that the signal aspects shown to the driver corresponds to the train staff in use.
Bishops Lydeard is the latest signalling project on the railway. The exact opening date of the signal box is unclear; three sources give the dates of 1902, 1904 and 1906. It is not known what signalling, if any, existed before these dates. The first frame had 25 levers with Stud locking and controlled a layout that consisted of a crossing loop, two sidings located behind the signal box and a third siding to a goods shed opposite, which is now used as a museum. In 1934, when the line from Norton Fitzwarren was doubled, a new 33-lever frame with tappet locking was installed. This was in use until 1970 when the signal box closed and the line was singled. BR removed all equipment from the signal box but left most of the track in place, all points were secured with clips. When the WSR resumed operations, the station was to be the southern terminus of passenger services. With the limited traffic at the time, One Train Working was used with a wooden train staff. To run-round trains, there had to be some alterations to the track at the south end and the Railway Inspectorate required that the points at each end of the platforms were connected to ground frames which were interlocked by the train staff. This system operated for many years, although as the traffic increased, the working of extra trains was restricted. To overcome this, it was decided to operate the station as a block post with Train Staff and Ticket to Williton on busy days. This provided the limited flexibility to allow a second train in the same direction after the first train had cleared the section.
In 1981, plans were drawn up for new signalling scheme. A new frame of 33 levers was installed, using part of the frame recovered from Westbury South, however, for various reasons, not least cost, the scheme was not completed. In 1994/5, the loop was extended to its present length of 275 yards. Once Crowcombe was opened, there was a greater necessity for signalling to make full use of the shorter block sections. In 1997 plans were drawn up for submission to the Railway Inspectorate. The station was still operated as a terminus so we had to allow for trains to arrive and depart from either platform; allowance was also made for through trains from Railtrack. Semaphore signals are used throughout except on the Norton section where there are to be colour light signals. The frame installed in 1981 was re-locked to operate the new layout; the colour light signals are to be operated by switches. Installation will be in two stages, the north end was brought into use between 4th and 11th August 1998 and consisted of one point, four single arm stop signals, a four-arm bracket signal and a new distant signal. The bracket signal has a stop arm and a calling-on arm for entry to each platform. The home signal for trains from Crowcombe is the third on the railway to be worked by a Westinghouse signal motor. A Westinghouse style M3A point machine, the same type as used at Blue Anchor, operates the point. Six track circuits are provided as the approach to the station is out of sight of the signal box. This is the first signal box on the railway where we have used BR specification 50-volt plug-in relays for the main interlocking. The older 12-volt shelf relays are no longer available in large numbers so we have to upgrade to the modern standard.
We suffered a few set backs early in the scheme, woodworm and dry rot were found in the signal box floor and some of the support timbers. The tiles on the roof where found to be loose and a number of them had to be replaced. This delayed the re-locking of the frame and the installation of the new wiring. We also suffered from a number of thefts. Most of the items taken appeared to be for “collectors”, these included a reconditioned ground signal. The signal did not have a lamp case attached so the thieves returned two days later to Crowcombe and took one from a working signal. We also lost two new signal arms and about £7000 worth of signalling cable in three separate occasions. One of the most unusual items taken was a number of track circuit bonds, these are lengths of galvanised steel wire that go across the rail joints in track circuits. They have no real scrap valve, and certainly no valve to a “collector”, but an unopened 25-kg bundle was taken.
Work on the south end will involve removing the south ground frame and connecting the points to the signal box. Five runs of between 100 yards and 200 yards are required, a total of 900 yards of rodding. The goods shed points are clipped out of use at the moment, but these should be first to be connected the signal box as stage 2a. Two more bracket signals are to be erected; the first was raised on Wednesday 12th April. There is also a centre-balanced wooden signal arm, this is all new as the original arm had rotted and there was rust in the metal frame. Most of the south end signalling has been installed, throughout the summer it will be connected up and tested. Even after testing we must wait for permission from the Railway Inspectorate before it can be brought into use.
The junction for the branch was at Norton Fitzwarren station, where the four-track main line from Taunton station split into three routes. The main line continued to Exeter as double track, while the other two routes were to Minehead and Barnstaple. The Barnstaple branch, which closed in 1966, was also doubled as far as the first station at Milverton. Norton Fitzwarren signal box closed on the same day as Bishops Lydeard and the four tracks were reduced to three from Silk Mill Crossing signal box. Two of the tracks formed the main line while the third was the single line from Williton. When passenger trains ceased on the branch, the main line connection was downgraded to freight only and a local drinks company “Taunton Cider” installed a private siding at this end of the line. Colour light signals were installed in the Taunton area during 1986, controlled from the existing Taunton East and Silk Mill signal boxes. At the same time, a new junction was laid in about half way between Silk Mill and the site of Norton Fitzwarren station. This was brought in to use when Exeter panel took control of the area in 1987. At the same time, a new junction was laid in about half way between Silk Mill and the site of Norton Fitzwarren station. This was brought in to use when Exeter panel took control of the area in 1987. There has been an increase in the number of through passenger trains over the last few years; this has resulted in a feasibility study to look into the upgrading of the junction to passenger standards. Taunton Cider ceased using rail in the 1990’s and the company has since closed. As part of the upgrading, the siding will be removed.
On 28th October 1996, one of the worst local storms in local history, together with a very high tide in the Bristol Channel, flooded the sea front area and railway in three feet of salt water. The average tidal range in the channel is normally about 6 metres, on this night it was over 8 metres. There was a large amount of damage to the railway including salt water in the axle-boxes of the rolling stock and the machine tools in the workshop. The signal store was flooded with the loss of over 100 relays and the level crossing was out of action awaiting spares. Services were suspended for five days. Total cost to the railway was over £100,000. The decision was made by the county council to completely rebuild the sea front as a precaution against future high tides. After much discussion, railfreight operator EWS, the UK subsidiary of Wisconsin Central, won the contract to haul the large boulders required to break up the waves. The trains would run through to Minehead with EWS motive power and crews and a WSR conductor driver. During the winter of 1996/7, there were some signalling alterations to lay in a new siding for these trains. The first train run in March 1997 and over a fifteen-month period, 106,000 tonnes of stone was delivered, on average, this was one train a day.
Williton and Blue Anchor were the only signal boxes in use when the WSR began passenger services in 1976. There are also four road level crossings, which are not located at signal boxes and are not, therefore, under the control of a signalman. Until closure of the branch, crossing keepers had been employed to operate the gates and protecting signals at three of these, while the fourth crossing at Dunster West was under the control of a signal box. The railway at that time was operated entirely by volunteers, and there was no one available to work these crossings. The solution was to convert them to automatic operation. There was no requirement of both tracks to Minehead for passenger trains and it was decided not to reopen Dunster signal box, fortunately, the Railway Inspectorate gave permission for Dunster West Crossing to become “Open”, i.e. no signalling required. The others, at Sea Lane (Dunster East), Leigh Woods and Roebuck required road lights and rail signals. Approaching trains are detected by track circuits, which are long enough to give the road users sufficient warning of the fastest train. The line speed on the WSR is 25mph but the design of the crossings has allowed for 40mph trains slowing down to 25 mph over the crossings. A standard road light unit for level crossings has a steady yellow for five seconds followed by two alternate flashing reds. Two of these units are provided on each side of the crossing. On the rail side, the driver will see a flashing white light when the flashing red road lights are operating but must look out for road users “jumping” the lights. If there is no flashing white, the train must stop before passing over the crossing and the fireman will hand-signal the train when the crossing is clear. New crossings now require a flashing red light to be exhibited to the driver when the flashing white is not shown.
At Watchet, the railway has a very busy footpath crossing between the town and the sea front. Miniature red and green warning lights are provided for indicating to pedestrians. A track circuit and a treadle in each direction detect the approach of trains. This is the only location where ac track circuits are used, standby power in provided by a 24-volt battery through a dc/ac inverter.
The WSR has two types of frames; both types were designed and manufactured by the GWR in the signal works at Reading. The 5-bar tappet locking frames date from the 1930’s. The GWR did not use tappet locking until 1906 when it produced a 3-bar tappet frame; its earlier frames had “twist” locking, where all the connections were rotated to engage the locking. Despite this complicated arrangement, several twist frames are still in use, although the last two on Railtrack have been converted to tappet locking. The GWR developed the Stud frame in 1892 as a replacement to the twist frames, when most other railways were changing to tappet locking. It operates in a similar manner to tappet locking except that the blades are curved; the radius of the blade is centred on the pivot point of the lever. The locking bars are known as “slings” and the wedges are round and known as “studs”. There is no locking tray, all the slings are arranged above and below the blade on a piece of 6 by 23/4 channel iron. This limited the amount of locking that could be accommodated and 37 levers was found to be the practical maximum. Any alteration required the entire locking to be disconnected, particularly if it was the bottom sling on a large frame. It was no surprise, therefore, that the GWR soon changed to tappet locking to replace the twist frames.
The power supply used in the signal box areas is standard 110-volt ac, 50Hz, which is obtained from the domestic supply of 230-volts ac. The isolated level crossings are fed direct from the domestic 230-volts to overcome voltage drop on the long feed cables. Locally, the crossing circuits use 24-volts dc. All equipment, such as relays, lever locks and indicators operate at various dc voltages and is mostly ex BR. Float-charged standby lead-acid batteries are provided at all locations to cover any mains power failure. We use two types of relays for interlocking. The older “shelf” type, are, as the name implies, designed to sit on a shelf. They were originally worked from low voltage dry cells but with the increase of the national grid power supply, rectified 12-volts is now used. We also use BR specification “plug-in” relays, which are available for 24 and 50-volt operation. They fit into pre-drilled bases mounted in specially designed relay racks. Track circuits are fed at 2-volts dc with relays designed to pick at a nominal 0.5-volts. Track circuit relays are available in both “shelf” and “plug-in” specification. Indication relays are manufactured to a lower specification, as they are not vital in the safe interlocking. Various indicators are provided in the signal boxes to repeat the condition of signals, points and power supply.
When the signalling is finished at Bishops Lydeard towards the end of 2000, this will be the last signal box to be reopened. Over the next few years there will be several projects, provision of cable along the railway to extend the Electric Key Token working and refurbishment of the original equipment at Blue Anchor, Williton and the level crossings. Maintenance, of course, will always be an ongoing task.
As a Heritage railway, we try to use signalling that reflects the history of the line but it should be remembered that all the equipment has been installed with a practical purpose in mind. We are an operating railway and are subject to the safety requirements of the Railway Inspectorate in the same way as the national track operator, Railtrack.
All the signal boxes are accessible from the public areas of the stations, except Minehead. This can only be reached from a public footpath that follows the railway from the station. Visitors are welcome, but please remember, this is an operating railway and when there are trains about, the signalman does have his job to do.