SVR S&T Dept.
Part of the new signalling diagram in Kidderminster Station box showing the dual control of the Network Rail signals reading onto the Severn Valley.
SIGNALLING NOTES - Chris. Hall
Accounts of the activities of the S&T department over the last three years have been notable by their absence. As the time goes by, the task of writing down what we have done becomes greater and greater. Since the last set of signalling notes in issue 180 (Winter 2012) we have been as busy as ever. I shall try to cover the period from October 2012 to October 2015 in this article. Looking back to the first article I wrote in Issue 128 in October 1998, so much has happened but, in most cases, we are simply refurbishing or renewing our equipment to ensure continued reliable operation. There are a few notable exceptions (new interface to Network Rail at Kidderminster, new Dock on No. 2 Engine Line at Kidderminster) where we have provided new facilities.
Throughout this period (since before 1998) we have operated a routine of regular scheduled inspection, maintenance and testing on all our equipment, quite separately from responding to any reported defects. At the time of writing there are very few outstanding defects and by the time this appears in print these will either have been rectified or, in some cases, referred to another Department for rectification. An example of the latter is the result of recent wet weather: the signal wire run for the Up Distant at Hampton Loade became rather overgrown. This was quickly spotted by the Duty Signalman and the Permanent Way Department has been reminded of their obligations under Rule 221 (j) to keep signal wire runs clear of vegetation. The Bewdley P-Way gang were despatched and the problem solved.
Actually I think we have been renamed again. The Signal & Telegraph Department became the Signal and Telecommunications Department and is now the Signal Engineering Department. The Department is responsible for the installation and maintenance of signalling equipment, and is not connected with the Operating Department which provides signalmen (although many members of the Department are also signalmen). (I'll still refer to us as S&T as that is what everyone still calls us.)
We now have three paid staff in the Department, our latest recruit being Ben who has been taken on as a new apprentice. So what have we been doing over the last three years? It is easy to overlook the routine maintenance and testing, now mainly the province of our paid staff, but it is the nature of this work that there is usually little to say about it although we do keep records to demonstrate that it has been done successfully.
We also respond to defects reported to our fault line and these are often interesting to investigate. One day comes to mind when we were called to Bridgnorth because the Signalman was unable to clear the Up Advanced Starting Signal. A most unusual combination of faults which took all day to trace and rectify during which Up trains had to be handsignalled past the affected signal. Another day at Bridgnorth, investigating the failure of track circuit 5T - through platform 2 - turned out to be a problem inside the signalbox and was solved by replacing the TPR (terminology is 'T' track circuit, 'P' repeat and 'R' relay, hence track circuit repeat relay) in the box.
Not all faults reported to us can be attributed to the S&T equipment: there are some faults we have to refer to the Permanent Way Department and one or two where our equipment has operated correctly but has prevented a signal from being cleared. An example of the latter is a fault report at Bewdley South that 14 disc (reading from the Down Inner Homes to the Rock Siding) could not be cleared as 18A points (Back Road/Rock Siding) were not closing up correctly. In our book that is not a 'fault' but correct operation of our equipment. In this case ash ballast had completely filled the sleeper bay in which the drive rod for 18B trap points ran causing the other end of the connection to stand open when reverse. A little work with a spade and we visited the box - the Signalman described the problem and we were able to say that we had already found the problem and rectified it (something that could have been solved by others after a bit of inspection). It would no longer be necessary to clip three sets of points to admit an engine to the rock siding.
At Bewdley North the signalman complained that 6 points (the crossover at the north end) were heavy and sometimes difficult to bolt 6B normal. We had replaced the drive to 6A points a year earlier, as the connection to the drive stretcher had become worn. A simple adjustment was sufficient to made the points more reliable. There is little further adjustment left on these points and in the longer term, we know that the P-Way intend to replace this crossover.
Over breakfast at Bewdley we had a report that 31A points at Kidderminster were difficult to bolt normal. This particular point is in the middle of the compound (a double slip, not a fenced enclosure) and is quite difficult to adjust as the components only just fit into the space available. We had completed our other work by tea time and so were able to attend the same day. We asked the signalman to try these points and the fault was repeatable so we made a small adjustment so that the points closed up reliably.
Following removal of fishplates for regreasing (a routine P-Way task), we received a report that track circuit AA (which runs from Bewdley South Down Home to Kidderminster Up Homes, excluding the berth tracks) was sometimes not clearing after passage of a train - we replaced some track circuit bonds on the single line that had been damaged by the work between Bewdley South and Kidderminster and the fault has not recurred since.
Probably the best way to cover the larger jobs (mainly routine refurbishment/replacement but also work forced upon us by major infrastructure renewal) is to take a trip along the line and mention the jobs we have done as we go. First though I would like to look back over the last 50 years or so. In 1958 the railway was very different - a signalling diagram, courtesy of the Signalling Record Society, shows the branch connection:
An extract from drawing L244 showing the branch connection in 1958. Diagram: courtesy of the Signalling Record Society
The facing connection remained in the form shown until some time after the passenger service ceased in 1970, so by the 1970s the signalling had been downgraded to a shunt connection controlled by a disc signal. By 1983 things looked rather forlorn:
The branch connection in 1983 just before the original link was severed. Photo: Dave Stowell
The Severn Valley land was fenced off later that year:
The closed Kidderminster Yard later that year. Photo: Dave Stowell
Leaving the only connection:
The remaining connection in late 1983. Photo: Dave Stowell
By April 2012 the resignalling was still a year away:
Resignalling still over a year away, the Exchange Siding has a 5m.p.h. limit in April 2012. Photo: Dave Stowell
And by November 2013 the Exchange Line had been realigned and the speed limit increased to 15m.p.h.:
The realigned Exchange Line in November 2013. Photo: Dave Stowell
As a follow up to the major work at Kidderminster to provide a resignalled link to the main rail network, 18 points and 19 traps were renewed by the P-Way in October 2013. We had already moved the signal wire run and some point rodding to allow the Exchange Line to be realigned but we now had a rather more difficult task: the toe of 18 points was now too close to the gantry base to fit the previous mechanical detection. We had forseen this and the electrical modifications for the Network Rail resignalling had made provision for electrical detection. Once the pointwork had been assembled in the Yard, we were able to assemble and fit and adjust our new equipment before the points were installed and so we were able to complete the work to commission the electrical detection during the possession of the Main Line to replace the pointwork, all trains using the Loop Line during this period. Part of the mechanical rodding run to these points had also to be replaced.
A major improvement at Kidderminster is our new S&T storage shed inside the compound (a fenced enclosure not a double slip) - a large steel framed building which we have fitted out with shelving to store refurbished and new equipment, particularly items not intended to be left outside. The mechanical lever frame from Kidderminster Junction has been recovered and stored here.
At Bewdley South we have now completed a major box rewire: a lot of preparation work is needed for a job of this type - running new conduits and wiring, each wire labelled at each end as it is installed, using luggage labels carefully prepared beforehand to suit the design. Existing circuits are 'top nutted' (internal wiring terminated on the incoming side of each link to allow the new internal wiring to be terminated for testing) where possible.This minimises the outage period as we normally try to do a job like this within a mid-week non-running period. Like so many of our jobs there is little evidence after the work that anything has changed!
At Bewdley North we removed many insulated drive rods to renew the paxolin insulation (fitted where lines are track-circuited) and also replaced the insulation on several soleplates - we had surveyed these and identified those where the insulation had deteriorated before they started giving any problems. We were able to do this on a running day as we could take a possession on the Down main (or Up Main or Back Road) and still allow trains to cross.
During Winter 2014 we were faced with a number of major jobs: work on Sandbourne and Wribbenhall Viaducts meant we had to remove our point rodding and signal wire runs over the viaducts and reinstate them after the work. Also during this Winter major work at the Elan Valley aqueduct near Trimpley by the Water Board would require the track to be lifted. Our signalling cable was therefore disconnected and drawn back south of the work area. The contractors laid cable troughing on completion of the work so that our cable could be quickly reinstated.
Drainage work at Arley (see issue 178) had been done as far south as the Up Starting Signal but in Winter 201x the south end points were to be removed and replaced whilst the ballast was dug out and drainage improved. This was fairly major work for us to reinstate the point rodding and fit new mechanical detection to the new switches, as well as reinstate the signalling cable. Fortunately the rails carrying the FPL bar did not need replacing and the rails and FPL bar were simply replaced as was. During 2015 we measured the FPL bar for replacement with a new 'T' section and refurbished hangers - measurment of the hole spacing is quite critical as en error of 1/16" over the fifty foot length can cause the bar to fail to sit right down on the rests. To do this work we had to disconnect the FPL bar and a handsignalman was provided to ensure safe operation. One hanger was subsequently replaced, about 1/16" closer to the station, to get the operation of this newly installed bar exactly correct.
The location cupboard at the north end of the station by the Down Main Starting Signal was also replaced - this work was associated with drainage work in 2012 when the cable from here to the box was replaced.
At Highley we had replaced the south end FPL bar within the last ten years and we have just measured up the north end FPL bar for replacement. The wooden post of the Up Home signal had deteriorated and had started to lean: we replaced the signal with a steel post signal, recovering the fittings from the wooden post as spares.
At Hampton Loade the location cupboard at the Down Distant is in process of being replaced - a seemingly interminable job as various minor difficulties surfaced. Returning towards the box during quite calm and clement weather, a tree fell across the line just behind the working party which seemed to sum up the job well. One phone call later and the trains were stopped until the trunk could be cut up and removed. We are planning to replace the north end FPL bar (the south end one was replaced a few years ago after a derailment) but that is not urgent.
The box was rewired over the Summer of 2013 and was commissioned in the Autumn after the end of the daily service. The work was done predominantly to enable the token machines to be moved so that the fireplace and chimney could be reinstated - the heavy token machines had been placed on the brick base of the former chimney for support - but also provided the opportunity to bring the wiring up to current standards. Commissioning test records and documentation were provided and the work checked by an independent qualified tester as per industry-wide practice. We have some timber to replace the decking on the Down Starting Signal Bracket but that will have to wait until the quiet period in the Winter.
Some of the larger jobs we have carried out include replacement of the FPL stretcher on 12 points at Bridgnorth (Platform 1/Platform 2 connection on the Cleobury road bridge) after a run through had left the original rather bent out of shape. In such a case our first priority is to ensure that the integrity of the signalling system is unimpaired: in this case by booking off the detection and instituting hand-signalling while we removed and repaired (in this case replaced) the damaged equipment. These points have been reported as 'heavy' to operate but we have disconnected our rodding and proved that the problem is with the P-Way. Another job for this Winter will be to replace the detection and FPL stretcher on 12 points at Bridgnorth as the P-Way intend to fit a 'half set' of new switches on these points as the switches have (allegedly) been damaged again.
As part of the development work at Bridgnorth, we were asked to move 4/18 signal (the signal fitted with a route indicator at the north end of platform 1) four or five yards further north. The deal we made was that we'd need the 'Wailing Wall Construction Company' to dig for us a five foot deep hole at the new position of the signal and be ready to help with jack hammers (to get the concrete poured around the signal post when it was installed off the post) and to be ready to pour concrete around the post in its new position. We also arranged for the services of the P-Way's road-railer and driver Dave Evans to provide the necessary lifting equipment. The Operating Department provided a handsignalman and we completed the job and recovered the signal wire wheels that were made redundant by the work, by the end of the day. Many thanks to all those who helped. The platform can now therefore be extended northwards and the 'kink' in the platform (where the original connection to the carriage siding was) straightened out.
As for every article in this series, it will get a careful scrutiny (and usually many helpful comments) from the Head of Department prior to publication. A final reminder that this article and the photographs associated with it, as well as other S&T information, can be viewed in full colour on the unofficial S&T (signals) web site at http://www.svrsig.org/ (or look for 'svrsig' on google).