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FEATURE
NORWICH - YARMOUTH - LOWESTOFT
Resignalling completed DAVID BICKELL
T
he block bells have fallen silent around Norwich and decommissioning of the McKenzie & Holland and Saxby & Farmer mechanical-lever interlocking frames and semaphore signals marks the end of an era dating back to the late 19th century.
Today, the new simple 2/3-aspect LED signals provide train drivers with a far superior forward view of the movement authority granted by the signaller sitting in the modern signalling centre at Colchester PSB. Achieving this outcome was anything but straightforward, with significant volumes of work associated with the new signalling, swing bridges, track renewals and a multitude of level crossings, not to mention technical challenges necessitating innovative engineering solutions. As the scheme entered the endgame, Mother nature intervened. The consecutive storms Ciara and Dennis made landfall during the two weekends of the 23-day commissioning blockade in February. Thankfully, the signalling project was able to continue with only minor re-planning, but concerns about safe deployment of a crane led to the cancellation of a separate bridge renewal project at Postwick within the same possession.
Rail Engineer | Issue 183 | April 2020
diagram) including a single line serving Berney Arms, a station with no road access serving walkers, bird watchers and boaters.
Wherry lines
Atkins selects ElectroLogIXS
The Norwich - Yarmouth - Lowestoft lines are marketed as the ‘Wherry Lines’ by the train operator, the name given in the late 18th century to a type of cargocarrying sailing barge with large sails. For the purposes of this project, however, Network Rail preferred the acronym ‘NYL’ although this isn’t strictly accurate. The Norwich station throat has a freewired route relay interlocking operated from the 1986 NX panel at Colchester PSB, whilst Whitlingham Junction was resignalled under the Cromer project of 2000 utilising Vaughan-Harmon VHLC interlockings controlled by a modular control system (MCS) signaller interface located at Trowse swing bridge signal box. The latter products subsequently became part of the GE Transportation Systems (GETS) empire, the signalling interests of which have recently been acquired by Alstom, a supplier to the NYL scheme. NYL signalling commences four miles out of Norwich near Brundall Gardens and controls forty route miles of railway (see
Atkins (part of SNC-Lavalin) was appointed signalling and civil engineering contractor and designs integrator, managing a host of supporting contractors and suppliers (see inset). Network Rail was responsible for the integration of the intended Postwick bridge works and management of the permanent way and telecommunications teams. The delivery office was based at Lowestoft, while the principal office was at Stratford. Atkins offered ElectroLogIXS computerbased interlocking technology, supplied by Alstom, which is already used extensively around the world (issue 176, July 2019). It communicates using internet protocol (IP), and off-site assessment has demonstrated compatibility with ETCS. The NYL project is the largest UK installation to date. ElectroLogIXS has a small footprint and allows longer copper tail cables to be used, such as signals at 1,600 metres and wheel sensor cable as long as five
