A phased programme of electrical work is currently underway to the tramway overhead supply in both the depot and depot yard area at Foulbridge. For some time it has been deemed desirable that the depot overhead within the shed would be reconfigured to free up an isolator in order that the yard outside could also be switched – it previously having been back-fed from the main tramway. The advantage would be to create an isolation on the yard area only when required as well as install the switching required for road 4/5 to be energised.
The tram group of Les, Peter and Mel, working with Hugh, have been carrying out phased re-wiring and preparations in readiness for the changeover of switches. A further modification has been to modernise the overhead indicator lights (seen in the photographs) as well as provide repeaters of these above the relevant switch. The switches themselves are overhauled items (by the group) and originate from the pedestrian tunnel under the River Tyne (previously being used for the escalator switching there). They are superb, robust and mechanically satisfying items and are being refurbished one by one so that four will enable required isolations to be created in this area. The switches are interlocked in such a way that the cabinets cannot be opened withoug the power being isolated, and additonally they have an earth function, which is also indicated by lighting above the relavant wire as well as on the repeater board. During testing, as seen in some of the images, the various lights and combinations of interlock were tested, as seen in the gallery below.
The photographs below show the work in progress and the final ‘Mega’ testing of the circuits to prove the electrical continuity and indicate any leakage to earth. A hand-operated magneto provides 1000 volts for testing purposes, the dial indicating fluctuation caused by any leakage in the system and thus a potential problem. This is the same test applied to new tramcars to the Museum and is, for instance, how Boat 233 was found to require work to its electrical system when the Mega test revealed a loss of resistance and therefore a leakage to earth somewhere on the tram.
Also shown is a rain soaked view of Darren and Mark hard at work patching and re-rolling the Pit Village street, which becomes very churned up after prolonged ice and snow settle on it followed by intensive footfall and passing of vehicles.