S & T Notes - issue 140

SIGNALLING NOTES - Chris. Hall

Another deadline approaches so it's time to put pen to paper again to bring you up to date with our activities from mid-February to early June.

Kidderminster

On 5 May the signalman reported that he was unable to release the electric lock on the Platform 1 to Down Main Starting signal (no. 62 signal). Some diagnosis of faults over the telephone is usually possible if we can ask the right question, so we requested a quick check to see whether no. 20 lock was similarly affected (it was). This pinned down the likely culprit to the lock proving contact on no. 58 lever (the Down Main Advanced Starting signal). Fortunately the fault did not afffect the train service although a few drivers were probably puzzled when being routed out from platform 1 via the loop (using no. 59 signal) but then that is why this signal has a route indicator (which shows 'L' for the loop and 'M' for the main). The fault was quickly traced to a stiff lock return spring housing and after dismantling and cleaning it was operating correctly again.

Bewdley South

A fault was reported on 16 February that the Down Main Distant would not drive to 'off' whilst the signal lamps were lit. There have been no recent reports of this fault, probably more due to the lighter evenings than the fault being traced. This is likely to be a problem with the power supplies and has so far proved elusive - in any case it is easily overcome by momentarily switching off the signal lamps. Replacement spectacle castings for the Down Distant and the Down Main to Back Road Inner Home are being prepared following reports from Drivers concerning poor indication at night.

Bewdley North

During the Easter weekend, the existing single disc signal at the base of the Up Inner Home bracket was removed and a newly constructed and painted double disc signal was installed. This is the culmination of much work behind the scenes and the upper disc now reads from the bracket to the Rock Siding, preceded by the running disc signal outside the box. This new signal and the recently installed Down Main Calling On signal were then brought into use on Easter Sunday, a temporary paper box diagram having been installed to allow the permanent diagram to be amended. The new disc signal reading to the Rock Siding will not see much use (except on occasional Saturday nights when the DMU stables there) although there is evidence it was operated for the first time on 3rd April 2002.

Arley

The signalling system is designed to prove that remote equipment is operating correctly, rather than make an assumption that it is. One example of this is that remote location cupboards at Arley are provided with battery backup for their indication circuits - if supply voltage falls below a certain level then an alarm 'standby in use' is initiated in the signal box to warn that battery backup is being used (and will only last a finite time). The 'lamps on' and 'power supply healthy' indications share a tone generator circuit from the Down Distant which has been repaired many times after thunderstorms and sometimes causes the power supply failure alarm to initiate when the signal is operated whilst the signal lamps are lit. Familiar, if occasional, fault reports to this effect have been reported now for some time but the fault was finally put to bed on 14 April when the tone generator circuits were upgraded and such reports should now be a thing of the past. On 31 March a fault was reported that the "activator rod" had broken on no. 10 FPL - this proved to be a broken drive rod from the last crank to the fouling bar and required the services of a handsignalman. Search for a replacement part on the Bewdley triangle and near South box by Tony Neath and John Smith was successful and a replacment was fitted the same day. Such parts are now quite hard to come by and what might appear to be a collection of scrap material can prove very valuable.

Highley

On 24 March it was reported that 10A points (the yard exit at the South end) were not making up reverse - investigation showed that the fishplates had been tightened by the P. Way so that the 'A' end of the points were sprung very tightly to the normal position. This only became clear after this end of the points was disconnected - after some adjustment they were booked back on on 13 April. Our equipment had operated correctly, preventing the signal from being cleared unless the points were proved to be in a safe position, the function of the detection provided for this signal. Similar difficulties with the north end points were reported on 31 May and this was corrected on 3 June. A nocturnal visit may be needed to investigate why the backlight on the Down Home cannot be seen - a fault reported on 17 May. A replacment spectacle casting is being prepared for the Down Starter.

Hampton Loade

The arm repeater on the Up Distant has been reported several times as failing to show a correct 'on' indication when the box is being switched in and the distant signal is restored to caution. This signal can only be cleared when the box is switched out so cannot easily be restroked once the box is switched in. With no signal ladder at this location, we have been unable so far to investigate and rectify this fault. It seems a simple job but requires at least two people and a long walk with a ladder. Our working week is fast approaching (mid June) and this is one of a number of jobs we will tackle that week.

Bridgnorth

On 6 April a small team descended on Bridgnorth to rectify a number of minor faults - some of the signal repeaters in the box were proving temperamental and some signal wires had got buried in ballast. The contacts on the signals were cleaned and the repeaters adjusted to maintain correct operation. Some lubrication and adjustment of mechanical parts and all was in order again.

On 28 April a small team (John Phillips, Derek Jones, John Smith and Tony Neath) booked off no. 11 FPL, 12 points and track circuit 11T in preparation for work by the P.Way department to replace the switch rails. All fittings were removed with the exception of the FPL casting and the boss of the FPL crank in the four-foot. Temporary approach releasing was applied to no. 1 signal, the Down Home, and 11T relay end cables and track bonds were removed. Assurance was provided that rail lengths would not change during the work.

On 3 May the same team (plus Dave Carr, Dave Kessel but minus Tony Neath) replaced all fittings with the exception of the protecting ramp (P. Way had only fitted the front stretcher at this stage). New reay end cables were run in and terminated for 11T, as the insulated joints had moved further away from the location, and the rail bonds were replaced. The approach releasing was removed and all equipment tested and booked on for normal running on the Saturday, so that the Handsignalman and Groundman were stood down.

A further visit was made on 1 and 2 June to carry out some fault finding, the services of a handsignalman being required during this work to ensure safe working of trains.

Routine maintenance

The unsung work of those who attend mid-week and weekend to carry out programmed maintenance continues behind the scenes to ensure that equipment operates safely and reliably. Routine testing of interlocks (detection, track circuits etc.) is programmed either 6-monthy or annually and continues to show that reliable operation is being maintained.

Planned work

Work planned for the immediate future is to rewire the Hampton Loade Up Distant, continue location maintenance (eviction of spiders, cleaning with WD40 etc.) northwards from Arley, preparatory work for the forthcoming rewiring of Bewdley North box, complete power supply testing and replace the timber platforms and handrails on Hampton Loade Down Home and Bewdley North Up Inner Homes. This work will be fitted around the normal routine testing programme as resources allow.