THE SIGNAL BOX

BRANCH LINES

 

THE WEST SOMERSET RAILWAY

A Description of the Signalling
by Kevin Weston

Minehead

Minehead box

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.

Interior view of Minehead box

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.

Beneath the floor at Minehead

Two views showing the mechanical interlocking between the levers in Minehead boxes. Above, 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 (below). Photos by Kevin Weston.

Another view of the interlocking at Minehead

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.

Storms

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.