Transport for London (TfL) and Balfour Beatty have confirmed they have finished work to renew 90-year-old points on the Piccadilly line tracks in Northfields.
The points were some of London Underground’s oldest assets.
They were replaced between Christmas Eve and 3 January as part of a synchronised operation to improve track, signal and power.
An unreliable double slip, leading into the depot, was replaced with a scissors layout and life expired points on the mainline were completely swapped out. London Underground’s engineering team also improved safety by aligning the substation gaps, which now means that traction current can be switched off on the eastbound and westbound track at the same time, to avoid workers carrying out maintenance in proximity to a live track.
By delivering works for the Piccadilly Line Upgrade at the same time as the points replacement, a full weekend possession has been avoided, delivering a saving of about £1.2m.
Work during this closure also began to install two new points in one of the sidings as the first part of the Piccadilly Line Upgrade works at Northfields, as preliminary work to allow for the construction of the new Northeast siding. Work is underway to prepare for a new fleet of state-of-the-art trains, which will service customers on the line from 2025, with more space, air-conditioning, walk-through carriages and improved accessibility.
Martin Broughton, from the London Underground Track Renewals Programme, said: “Replacing these 90-year-old elements is vital for the smooth running of the Piccadilly line. Thanks to our co-operation with Balfour Beatty, and at the least inconvenience to our customers, we’ve combined works, delivered vital improvements, and saved £1.2m and a future weekend closure in the process.”
Alistair Mclaughlin, Balfour Beatty project director, said: “This is an incredible milestone – one that is testament to the hard work and dedication of our expert team who worked around the clock over the Christmas period to safely and successfully replace some of London Underground’s oldest assets. We now look forward to watching as these essential upgrade works transform travel in the capital; making way for the new fleet of trains which will significantly reduce journey times and increase passenger capacity.”
A Balfour Beatty Kirow 810 rail-mounted crane was used to install 43 track panels that were pre-built and delivered to Northfields depot. 35 engineering trains, seven tracked excavators and two dozers were used to remove the old track and 2,000 tons of spoil, and to deliver 2,000 tons of new granite ballast.
Engineers replaced the old-style bull head rail with modern flat bottom running rail, and the electro-pneumatic point machines with new Voestalpine Unistar HR electric point machines, which were first used on the London Underground network at South Harrow in 2019.
The updated 21a/b points are operating with two Unistar machines on each point end working in tandem instead of one machine working back and forth. This is the very first time that network points have been powered this way on the Tube.
