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Project Leader David Holmes reports in WSR Journal 116:
When Contractors moved onto the Association's Norton Fitzwarren site in early October 2006, the construction of the planned turning triangle moved from a paper exercise into the realms of reality. For the first time Association members can see, albeit from a distance, tangible evidence of the progress of this exiting project. This progress is set to accelerate into the New Year to become a major civil engineering exercise.
Physical work actually started in November 2005 when a new lead was laid near Norton Bridge which will ultimately give access to the triangle site. Many have commented that the location of the lead is not as shown on the original drawings, but this was merely the result of a risk and sighting review which had shown a location some 200m before Norton Bridge to be a safer location. The lead has been extended during the course of 2006 into a siding that currently runs up to the position at which it will diverge from the West Somerset Railway 'main' line and onto the fields. Further progress is dependent upon the completion of the first part of the new formation, which is scheduled for early in 2007. This location has become known as Allerford Junction (it would be nice to say "Change for Barnstaple!").
Until November 2005, the proposals for construction had been based on importing clean demolition rubble to form the core of the embankments. We would have waived the fee for tipping in favour of having the rubble neatly arranged into the embankments and covered with topsoil effectively constructing the formation at no cost. However, one of the Conditions imposed by the Planning Permission had effectively been a restriction on the movement of lorries and the volumes of rubble proposed for import had begun to raise concerns at Somerset County Council Highways Department. At the same time, the two nearest projects from where we could have sourced suitable rubble had delays of their own which meant neither was ready to begin demolition. As this Journal went to press, one of the developments was still locked in Planning Application wrangles and of the other there has been no news - we would probably still be waiting to start.
At about the same time, Network Rail approached us with a proposal to supply ballast brought to the site by rail at no charge. Network Rail has established a base for their High Output Ballast Cleaner at Taunton's Fairwater Yard less than a mile from the site. This impressive machine comprises a ballast lifter and up to twenty aggregate wagons, each fitted with sieve trays and a conveyor. The train works a section of plain track each weekday night when the ballast lifter removes the ballast from beneath itself and conveys it back down the train, where it is sieved and the fines and dirt taken out and placed in selected wagons. The cleaner stone is mixed with new ballast and conveyed back along the train to the ballast lifter where it is dropped back into the formation. The train, which has gone out with clean ballast, now returns to its base with its load having cleaned several hundred yards of track in a single pass.
The fines and recovered aggregate now need to be unloaded and fresh ballast loaded for the following night's work. This requires the train to travel to unload and then reload and in addition to the daily maintenance means a very tight timescale to turn the train round each day ready for the following night. Network Rail reasoned that if they could unload the fines and aggregate within a mile of their base this would save a significant amount of time each day.
The offloaded ballast meets a basic Highways aggregate specification and is ideal for building the embankments where we require a source of good clean material with some fines and binder in it to achieve proper compaction and prevent it from moving.
In return for the West Somerset Railway accepting the aggregate and in lieu of forming the banks, Network Rail agreed to supply sufficient redundant track materials to allow the triangle to be laid by the Association. As these materials would come in by rail, it meant there would be no deliveries of track materials by heavy vehicles. With fill, rail and ballast coming in predominantly by rail, the Highways Authority and thus Taunton Deane Borough Council gave the proposals their blessing and approved the necessary amendments to the original Planning Permission.
The changed plans required some rethinking of the approvals from the Environment Agency, as we would need to form an unloading area in a position where there was currently a main ditch. It was agreed to divert the ditch to run alongside the new embankment and to fill in the original course of the ditch. This would also work better with the drainage ditches that already bisected the fields and with the planned 'compensation pond'.
The Association worked closely with Consultants employed by the developers of the Taunton Cider site who were constructing a computational model of the hydrology of the area to study flood flows. The Association supplied them with full details of their proposals and a survey of the ditches and culverts in the area. Unfortunately the results were not available in time for submission with our plans to the Environment Agency, but we have been verbally assured that our proposals improve the general flow of flood waters in the area and do not contribute to any worsening of the situation for the villagers.
There can be few fields that are so full of services - the land is crossed by a main 400Kv National Grid line from Hinkley Point, a 33kV local distribution line on poles, a buried pumped sewer and a potable water supply pipe in addition to the drainage channels already mentioned. The proposed triangle had to be threaded between these and the various services have in no small way led to the layout of the triangle being constructed. The existence of the disused Barnstaple formation also played a major part in the layout of the scheme, as no flood compensation is needed for this section because the earthworks already exist.
There could be no thought of any alteration to the 400kV pylon route - these cost as much per mile as a Motorway to construct and it would be out of the question to move it. Fortunately, even with the track running on raised embankments more or less beneath the cables there proved to be sufficient clearance for safety and Transco agreed to our proposals.
Western Power Distribution were consulted as the lower 33kV pole line was definitely too low to allow locomotives on a raised embankment to pass beneath. Of course, nothing is simple and at just the point where we would need to raise it, this line passed below the 400kV pylons and there was little or no room for movement. Western Power were aware that the original line had been installed without a wayleave agreement with the land owner and have offered to underground almost all the line for us for a nominal contribution from the Association in return for a conventional wayleave agreement. The Association have accepted this offer and the line should be buried in the Spring.
There is a buried sewer pumped at 10Bar (150psi) taking effluent from the Cotford St.Luke development to the treatment works. The route crosses the edge of the field, passing beneath the new alignment as it enters the fields and then below the compensation pond and on under the main line. Fortunately, the sewer is deep under the compensation pond as it is lowered to pass under the main line but had to be dug by hand where the new alignment will cross it nearer to Norton Bridge. We have worked with Wessex Water and established that the sewer is deep enough to be unaffected by locomotives passing just overhead, but have agreed additional protective measures where the new adjacent ditch almost exposes the top of the pipe. A by-pass was installed under the main lines when the sewer was put in and a complex series of valves and manholes up against the Barnstaple branch have fixed the extent of the eastern chord for us as Wessex Water will require access to the manhole to operate the by-pass valves. This effectively fixed the eastern extent of the new chord.
A small potable water line runs across the fields providing a private supply to a single house but fortunately it is not located in the direct path of the new embankments. However, even this surprised us in the end, when the route was not as outlined to us and, sure enough, a JCB managed to find it where it was least expected during the dig for the new culverts! Before we could fix the break, Wessex Water and the householder arrived to find out what had happened, but fortunately everyone saw the humour in the situation and the supply was quickly restored.
Negotiations with Network Rail on the detail of the HOBC scheme continued through the Summer of 2006 until agreement was reached at the beginning of October. This allowed the Association to employ Contractors, who had been working with us on the project for some time, to move onto site and start preparing the area for the first aggregate deliveries.
They stripped the topsoil from the compensation pond and had planned to take out 500mm of clay before putting the top soil back and reseeding the area. Unfortunately, heavy rain curtailed this plan and the area lay stripped of topsoil for some weeks waiting for a drier spell. Once drier conditions arrived the pond was completed and the Association is now the proud owner of a 12,000m2 pond - in the heavy rains this Autumn, this has already been called into use and after an inspection, the Environment Agency pronounced their satisfaction at the works.
The excavated clay has proved ideal to lay as a sub base for new embankments and both chords have been set out and the clay deposited and compacted. This will enable a rapid start in the Spring when the ground has dried out from the current non-stop rain!
At the Norton Bridge end of the alignment, the contractor has stripped the soft topsoil from the line of the embankment and installed the culvert to take the ditch below the new formation. The Environment Agency have asked for large 1.0m diameter culverts and the preformed plastic tubes have been partially sunk into the bed of the existing ditch to maintain the profile of the track bed on top. A structural concrete raft has been cast over the top of the culvert and the whole excavation has then been backfilled ready for track to be laid across the top.
Two trial deliveries by a shortened HOBC occurred in late November, each delivering about 250 tonnes of aggregate. The West Somerset Railway will provide a conductor driver for each HOBC, who will also work with the contractors to ensure the safe operation of the train and trackside excavator plant. Network Rail and the WSR have nowdeveloped a joint Operating Procedure to cover the movements and unloadong. When full deliveries start in the New Year, each HOBC will deliver up to 1000 tonnes. These early deliveries allowed the various procedures to be practised and perfected and provided enough fill to cover the new culvert close to Norton Bridge and to surface an unloading area for the HOBC to use in the New Year. Watched by senior staff from Network Rail, the operator First Swietelski and representatives from the West Somerset Railway Company, Association and John Luffman, the contractors, the deliveries went smoothly and each 250 tonnes was offloaded in less than fifteen minutes.
The Association's volunteer Gangs have been kept busy by work on the new scheme. The Special Projects Group has been busy clearing years of undergrowth ahead of the arrival of contractors and during September and October changed the landscape at the boundary with Network Rail with the grubbing out of a large area of brambles and scrub to give space for secondary storage of aggregate should the need arise. The Permanent Way Gang have meanwhile been working on the West Somerset line past the site which has been largely relaid this summer with concrete sleepers and deeper ballast in preparation for the arrival of the heavier trains. Both gangs came together in November to lift and recover some of the internal sidings from the old cider works. Meanwhile, the Signal & Telegraph Gang have been installing the ground frame at Allerford Junction.
In early November, Network Rail were given possession of the first couple of hundred yards of the branch in order to provide them with space to unload and manoeuvre track to relay the connection behind Taunton Cider works. The sight of a Freightliner Class 66 and rake of wagons gave a foretaste of the future HOBC workings, whilst redundant materials left from the relay will be put to good use on the triangle when the time comes.
The triangle has been designed to work independently from the existing WSR line for a number of reasons. Foremost of these is the proximity of the connection between the Barnstaple formation and the existing WSR line to the boundary at 165.1/4. If the two arms of the triangle came together too close to this boundary then there could be inadequate room within the WSR section to fit a large locomotive and support coach, severely restricting the flexibility of the triangle. Any overrun would lead to an immediate incursion onto Network Rail - a SPAD, and this would have been extremely undesirable.
The decision was therefore taken to strike out and construct the triangle away from the existing line which would allow us to form a headshunt precluding overruns onto Network Rail and allowing a locomotive and several coaches to be turned in a single move with obvious benefits for our own stock which suffers terribly from single-side weathering. A minimum ten chain radius was set - ideally we would have liked more, but this was the maximum that could be fitted into the space available and still avoid the services mentioned previously. The triangle will therefore diverge from the existing line from the end of the Allerford Siding at the boundary with the Fishing Lake and run parallel to the 400kV line. A lead will divide the track into two arms, which will run together for a short while before splitting left and right. The short parallel section will mark the second unloading point for the HOBC as construction moves onto the formation.
The eastern chord will cut back toward Taunton passing between the remaining 33kV overhead line poles - the power line is significantly higher at this point as it goes over the main line - and joining the original Barnstaple formation just before the Wessex Water sewer manhole, which has to be kept uncovered for access. The western chord will head toward Barnstaple threading between the 400kV pylon and a large and attractive oak tree before joining the original Barnstaple formation, which is rapidly converging toward the chord at this point. New culverts will be provided where the two chords cross the ditch alongside the old formation.
Initially, sufficient track will be laid to form a single track triangle. The track will be supplied in 30' panels by Network Rail and will require laying and tamping by Contractors as the amount of work will be beyond our own teams. Needless to say we shall have a ready supply of ballast to lay!
The layout will allow for the track to be extended back to the old bridge, long dismantled, across Allerford Lane and perhaps doubled if required at some time in the future. The second 'Down' track could also be connected if required at the Taunton end to provide a departure line to Network Rail. This additional trackwork is for the moment very much in the realms of the possible rather than the likely.
It is hoped that the first track will be laid early in 2007, but it is not anticipated that the triangle will be available for use until the 2008 operating season. The necessary licensing applications are being processed by the Office of the Rail Regulator to allow the WSR Plc. as holders of the Safety Case to operate the new facilities once they are completed. With pressures on the land available near Bishops Lydeard it is anticipated the Steam Fayre will move to the site in 2008 bringing the possibility of adding steam locomotives including perhaps some visiting excursion locomotives to the Rally site alongside the other exhibits and thus providing a truly unique event. However, much remains to be done before that is possible and, needless to say, whilst work is going on the site is in the hands of the contractors and not accessible to the general public which must regrettably include Association members at the present time.
The initial work is being funded from Association funds with a large proportion coming from the donations received for the project over the last two years. Proceeds from the raffle have also been dedicated to the project. Once aggregate deliveries start we hope to have sufficient excess to be able to sell material into the local market which will generate a small revenue stream to help offset the costs of the construction and track laying, but it is certain additional funds will be required to extend the basic track layout left after the HOBC has left, to provide Signal & Telegraph equipment and to further develop the site.
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