SVR S&T Dept.
http://www.svrsig.org/svr/Iss207.htm

S & T Notes - issue 207

SIGNALLING NOTES - Chris. Hall

I have started putting pen to paper rather late this time, having just noticed that the 1st August deadline is looming. Looking around for material, I have noticed that the list of reported defects is unusually small so we are keeping nicely up to date. We are now looking to the Winter work for 2019/2020 which will be a rather longer non-running period due to the work on Falling Sands Viaduct.

During this period, the track between the viaduct and the tunnel is to be renewed with flat bottom continuously-welded rail. A set of points is to be installed at Foley Park just beyond the berth track circuit for the Kidderminster Up Home Signals to allow sidings to be added here at a later date. Our work this Winter is therefore to provide continuous monitoring of these points and to ensure that they are mechanically locked in the correct position.

We are therefore building a ground frame which will, on completion, be released by an Annett‘s key. It will operate the facing point lock and points mechanically and electrical detection of these points will be indicated in Kidderminster box and will be added to the single line controls.

Our work this Winter will not aim to complete the installation, nor will the sidings be laid immediately. However it still means a lot of preparation so that we are ready to install our equipment to provide safe working over the new points in the main line. We have acquired a set of electrical detection from colleagues on the North York Moors and have spent a couple of months refurbishing and repainting it.

The existing signalling cable over Falling Sands Viaduct does not have sufficient spare cores to add the necessary indication circuit (which will, when completed, show that the ground frame release has been given up and the points locked for normal running) and so will need replacement. This will be done as part of the works on the viaduct. The necessary changes to the wiring of the location cabinets concerned have been identified and are not extensive.

For a couple of months now we have been rebuilding the old Kidderminster Station ground frame so that it can be installed on site this Winter. It will be a three lever ground frame provided with an Annett‘s release key corresponding to the Bewdley South - Kidderminster occupation key. A cast concrete base with brickwork and timber planking will be required and this, also, will be provided as part of the Viaduct works. Thanks again to Gary Townley for re-welding two more catch handle rods, fitting new springs to replaced ones that had corroded or failed.

The new pointwork will need an insulated sole plate (provided by the P-Way Department) and a facing point lock casting (provided by us). We are hoping that the points will be assembled in good time so that we can drill the holes, mark up and measure to the necessary tolerances, machine the facing point lock stretcher ports accurately and make a trial assembly in plenty of time before the Operators will start to want to run trains.

Inevitably we are the last link in the chain‘ in this sort of work squeezed between the heavy P-Way work to fit the track and the start of the running season. Planners who do not understand signalling invariably do not allow sufficient time for completion and testing of our works.

During Santa running in December, the platform 1 starting signal at Kidderminster had failed with a broken down rod between the route indicators and the signal. A permanent welded repair was effected during the week commencing 14 January, with thanks to the C&W for their help. However this failed in April and we manufactured a brand new down rod, which was fitted in June. This consists of a long length of bright mild steel bar, bent to the right shape, welded to a short section of threaded bar which screws into a clevis pinned to the balance weight lever. The other end has a welded collar which connects to the signal arm casting via a pin joint.

The electrical section have been spending time at Hampton Loade bringing into use a replacement location cupboard which had been installed a few years ago at the Down Distant signal. The experimental LED lamp at Bewdley North Up Home Banner Repeater has been made into a permanent fixture with a purpose-built mounting piece, replacing some hand-crafted timberwork. A new cable tester has also been put through its paces. A test box to function-test plug-in relays has been manufactured and has been used to identify relays which need servicing.

A reminder that this article, as well as other information on Signal Engineering, can be viewed in full colour here on the unofficial Signal Engineering web site.

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