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Rail Engineer • September 2015
Demonstration panel pictured right.
The entrance signal clears to a ‘proceed’ aspect when the required conditions specified in the signal control tables have been satisfied. As the train progresses, the white route lights change to red as each train detection section becomes occupied. The red lights change back to white as the train clears the sections and the first route light at the signal flashes to remind the signaller that he must rotate the entrance switch back to normal. Incidentally, the last WR Integra panel box, at Oxford, uses the standard NX push-push configuration rather than turn-push. The route setting commands on the panel operate ‘nonvital’ ‘Post Office’ type relays which form a push-button interlocking ensuring that requests to set conflicting or unavailable routes are immediately rejected. These relays feed out route setting/cancel commands to the appropriate fail-safe interlocking which moves points and clears signals only if it is absolutely safe to do so. This is achieved by the WR’s own design of relay interlocking known as ‘E10K’. There is usually an interlocking within the same building as the panel, for example as at Swindon, covering signalling in the station area. Relay interlockings are usually situated close to the points and signals that they control. Thus a panel will also control what are termed remote interlockings. For example, at Swindon, one of several remote interlockings is provided at Wootton Bassett, being connected to the panel by an electronic ‘Time Division Multiplex’ data transmission system. At Swindon, the original TDM systems have been replaced by Delphin 1024 Multiplexer TDMs supplied by GE Transportation Systems (GETS). The near-vertical panel at the back was originally used for the Sodeco electro-mechanical train describer and signal post telephone buttons. Descriptions were set up using a telephone rotary dial. The noise on the operating floor of a train description stepping from berth to berth resembled a call being set up in a Strowger electromechanical telephone exchange that mature readers may recall! Reliability fell away as time progressed and the system at Swindon was replaced with an LED train describer for a few years, followed by a Vaughan VDU system in the mid1990s. Much of the space on the back panel is now used as a notice board.
Birth of the Swindon Panel Society The story began back in September 2012 with two railwaymen, Danny Scroggins and Tom O’Flaherty. Both thought it was a shame that all the WR panels would close, and a generation of signalling technology would eventually be consigned to the skip without any example being saved. It was felt that it would be difficult to obtain support for preserving a static, non-working example. However, the idea of preserving it in a simulated working state, wiring it up to a computer to simulate the passage of trains and thereby providing a hands-on educational visitor experience, was a lot more viable. The concept, already proven for lever frame boxes such as the former Exeter West Box now located at Crewe Heritage Centre, might now include a power box. In order to support these objectives, the new Society was formed. Swindon panel was chosen. It is in reasonable condition, and the track layout isn’t overly complicated in any particular area obviating the need for extensive electronic interfaces and complex simulation coding, yet the panel is long enough for three or four visitors to operate the panel at the same time. £1 has already been paid to Network Rail to secure the purchase of the panel which will be handed over when decommissioned in the coming months.