The preserved Swanage Railway in Dorset featured in issue 86 (December 2011), which described the control and communications systems and featured the three signalboxes at Swanage, Harmans Cross and Corfe Castle. The article hinted of the intention to extend services to Wareham on the Bournemouth-Weymouth main line, maybe as early as 2013. That was overoptimistic but, since 13 June this year, a regular service has started, the first time since 1972, when BR closed the line, that timetabled trains have run over this section.
Freight services had continued from Worgret Junction, where the branch joined the main line, to Furzebrook for trains associated with the extraction of oil from nearby wells at Wytch Farm oilfield. This was fortuitous, as it maintained the connection to what was then considered a long siding.
The Swanage Railway gradually re-built the line back from Swanage to, firstly, Herston Halt, then to Harmans Cross, and finally through Corfe Castle to Norden. This was established as a railhead for people to park and take the train to Swanage, where traffic congestion was a major concern.
In 2002, the final length of track was laid to join the newly created railway with the Furzebrook siding, thus permitting the occasional special train to visit the line. However, without proper signalling with the main line, there could be no semblance of a regular service.
So why has it taken so long to re-establish the full route for passenger trains and what has been required? Rail Engineer went to meet Mike Walshaw, the project manager for the signalling system between Norden and Worgret Junction, to find out the detail.
Basic signalling requirements
The Swanage Railway uses traditional signalling practice with signalboxes containing mechanical lever frames, semaphore signals, and electric token and tablet machines for the single line sections. The mainly volunteer operators are familiar with this operation and it was decided to maintain something similar for the Wareham extension.
However, with the Poole to Wool main line being re-signalled using modern colour light signals and track circuit block, interfacing the two technologies was always going to be something of a challenge.
The line from Corfe Castle to Norden was originally worked with a train staff, allowing only one train in this short section. At Norden, a run round loop exists for the steam service loco to run round its train, and is a continuing requirement.
This method of train staff working would not be appropriate for any onward service to Wareham and thus, when the new Corfe Castle signalbox was commissioned in 2011, the section was converted to NSKT (No Signaller Key Token) operation with train crews being responsible for the token activity at Norden. This set the scene for the creation of a new NST (No Signaller Token) section from Norden to Worgret Junction for the extended service.
The new token section extends from the barrier-controlled level crossing named ‘Norden Gates’, on the London side of Norden Station, as far as Network Rail’s colour-light junction-protecting signal at Worgret Junction (PW5750). To place the London-end token machine on the branch line short of the junction would mean stopping trains there to pick up or give up tokens, which was deemed impractical.
Instead, two token machines are provided at Wareham Station in enclosed location cases at the east end of both the Down and Up platforms. Swanage trains normally use the Down platform but trains can access the Up platform via a crossover should South West Trains’ Weymouth-bound services be running late.
The Poole to Wool section, including Worgret Junction, is controlled from the Dorset Coast Panel at Basingstoke SCC (Signalling Control Centre). This has a carefully designed interface such that the signal leading on to the Swanage branch cannot be cleared unless a token has been taken out for the section to Norden Gates, a workable solution.
Design and procurement of equipment
Much equipment was required to allow this extended operation. A newly created level crossing at Norden Gates (see later paragraph) meant that a crossing keeper’s cabin had to be provided. Although this looks like something acquired from another site, it was actually purchased in kit form and is based upon the erstwhile Lyme Regis ground frame cabin – it was erected in a single day.
Signals to protect the crossing are of the semaphore stop type with electric motor operation, together with fixed semaphore distant signals. The cabin has no levers, operation of the signals and points being by rotary switches on the block shelf, electrically interlocked with each other with indicators to show the status of each item.
The line from Norden Gates to Corfe Castle is track circuited and there is a Train Approach Treadle for trains approaching from Wareham to alert the crossing keeper that the barriers need lowering.
Specially adapted Tyers Electric Key Token machines are installed at Norden Gates, plus the two at Wareham, together with 30 newly manufactured tokens for the section. A small number of ground frames to access sidings along the route are unlocked by insertion of the token, including one location which is the road-rail access point for the railway. Should there be a ‘shut inside’ requirement for any of these, then the token has to be returned to Norden Gates by a responsible person.
A 30-pair 0.9mm copper conductor cable has been buried between Corfe Castle signalbox and a signalling-equipment interface with Network Rail, catering for both signalling and telecommunication needs. It connects into a similar Network Rail cable to give communication with the token instruments at Wareham. Direct-line telephones link Corfe Castle signalbox with Basingstoke SCC and the three token machine locations. There are also dial-up phones at Corfe Castle signalbox and Norden Gates, connected to the Swanage Railway telephone network and the BT national network.
Norden Gates level crossing
Passengers intending traveling by train and parking at Norden, also commercial traffic to Wytch Farm Gathering Station, use the level crossing. When only the occasional excursion special used the line, hand-signal flags and moveable barriers were acceptable for controlling the rail and road traffic. However, now that a regular service is being introduced, and with the density of road traffic, it was necessary to provide a full Manually Controlled Four-Barrier (MCB) crossing.
Such a crossing can be very expensive. However, the Swiss company Schweizer Electronic produces a ‘complete’ package based upon an industry-standard PLC (programmable logic controller). The kit comprises all four barrier machines and booms, the flashing light ‘wig-wags’, the audible warnings, plus a lineside cabinet which houses the programmed PLC with all of its line connections and standby power supply. The manual crossing control buttons are contained within a small console mounted on a plinth in the crossing keeper’s cabin.
Whilst the package is a complete entity, it has to be interfaced to the operational railway which, for Norden Gates, proved to be quite complicated. The design was carried out by a signalling expert from another heritage line.
In the Down direction (from Worgret Junction), the control is relatively simple. The crossing is protected by the electrically operated home signal (No 32), which cannot be cleared unless a token for the Norden Gates to Corfe Castle section has been released (by the Corfe Castle signalman), the barriers proven as lowered and the crossing proven as clear.
For the Up direction (from Swanage), it must be remembered that the steam service operates only as far as Norden. There, the locomotive needs to uncouple and proceed to the Engine Release Spur, off the main line leading to the level crossing via a set of motorised points, before running round its train. This procedure does not require the presence of the crossing keeper or the barriers to be lowered, even though the loco gets very close to the crossing. Its movement is controlled by an electrically operated shunt disc signal (No 5), which can be set to clear automatically after a timing sequence. The token for the Corfe-Norden section is then used by the train crew to unlock two ground frames so they can change the loop points at each end.
The through train service needs a different procedure. On approaching Norden station, either by the occupation of a track circuit or, for stopping trains, by the platform staff operating a ‘train ready to start’ (TRTS) plunger, the prompt for the barriers to be lowered is given. The crossing keeper will have set the points for the level crossing and the Corfe Castle signalman will already have released to him a token for the Norden to Worgret section.
The crossing keeper, when prompted, lowers the barriers and clears semaphore signal No 4 for the train to proceed over the crossing and on its way. Tokens are exchanged with the loco crew by the crossing keeper, who has been provided with token-exchange platforms to facilitate this operation.
There is a need to minimise the time that the barriers are lowered, hence the different prompts for barrier-lowering to achieve as short a time as possible. Barrier raising is manual, by pushing a single button on the console.
Since the primary reason for the crossing is road access to Wytch Farm Gathering Station, BP generously contributed to the cost of the system, for which the Swanage Railway is very grateful.
Trains and rolling stock
Because the trains to Wareham operate over Network Rail tracks, they must have main line certification. This entails the provision of AWS/TPWS, GSM-R radio and on-train data recorders, as well as having the correct wheel profiles and maintenance certificates.
The Swanage Railway has a Class 117 three-car diesel unit and a Class 121 single (bubble) car, both being earmarked for the new service. Whilst preparatory work has been undertaken, unfortunately it was not possible to complete the work for the 2017 trial Wareham Service. Coming to the rescue has been West Coast Railways, which has hired out Class 37 and Class 33 diesel locos to top and tail a hired four-coach set. West Coast staff are in attendance to familiarise Swanage train crew with their locomotives.
Now that the service has started, Swanage crews drive and manage the train and this arrangement will remain in place for 2017. Next year should see Swanage Railway’s own DMUs operating the service.
The 60-day trial service has seen respectable loadings so far, although it is recognised that a certain novelty factor exists. The trains provide four services a day until 3 September, running at two-hourly intervals on Tuesday, Wednesday, Thursday, Saturday and Sunday. The turn-round time at Wareham is only nine minutes, so as to minimise any potential interference with South West Trains’ services. Fitting this in with the two-train steam service to Norden, which operates every day in the Peak Timetable, is carefully planned, with trains crossing at Corfe Castle or Harmans Cross as appropriate.
At Wareham, a separate Swanage Railway ticket office has been set up near to the main entrance and the platform indicators are programmed to show the Swanage services. It is hoped that the service will become a regular feature of the area’s transport plans, offering new opportunities for locals and holidaymakers in the Bournemouth, Poole and Weymouth localities. In 2018, 90 days of operation are planned.
Some future plans
Norden Gates is manned by a crossing keeper, who has to be on duty all the time the Wareham service operates. Thoughts are therefore being given to controlling the level crossing remotely from Corfe Castle by CCTV monitoring, which will give greater flexibility.
At Wareham, there are sidings on the London side of the station which could be used for stabling Swanage trains in between South West Trains’ services. Currently, a barrier-controlled foot crossing over the tracks prevents these sidings from being used, but Dorset County Council is planning to provide a disabled-access footbridge over the line which will bring safety benefits all round. Once in place, this could lead to steam services over the extended line.
Operating a service beyond Wareham, perhaps to Bournemouth, is a vision that some have, giving travellers greater access to Swanage. It would mean the Railway becoming an Open Access Operator, so it is very much a long term plan.
Mention must be made of Dorset County Council, which have been very supportive in the reinstatement of the entire railway and which may influence things into the future.
For now, congratulations to the Swanage Railway for its new venture as it joins the North Yorkshire Moors and the North Norfolk Railways as lines which have negotiated running heritage railway trains over Network Rail tracks to a station operated by a franchised train company. May this venture be very successful.
Thanks to Mike Walshaw, Mike Southey and to Fraser White for taking time to explain the operation of the extended line.
This article was written by Clive Kessell.
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