PWI site visits to the Underground Northern Line Extension (NLE)

During 2019 I organised a series of visits for PWI members to the Northern Line extension (NLE). Parties formed of members from the London, Wessex and Thames Valley Sections were able to visit the construction works at the new and stations in south-west London.

4 April 2019 - Nine Elms station 2 May 2019 - Battersea station 13 November 2019 - Nine Elms station.

At Battersea we were fortunate to inspect the newly installed scissors crossover at the approaches to the terminus. This Cv 9.25 flat-bottom rail layout is installed on Sonneville ‘Low Vibration Track’ (LVT) system. It was noted that the Sonneville LVT ‘booted’ block system is also the track-form in the new running . These tunnels, being larger in diameter to accommodate emergency services access routes, enable the use of the Sonneville LVT system on the tube network.

We also inspected the construction of the Photo 1: Nine Elms station. new Battersea station which supports the new development buildings being constructed above by the Development.

Two visits were possible to the new station at Nine Elms which is a deep box construction with secant piled walls and ‘Top down’ construction using ‘off site construction practice’. Many of the main structural elements were constructed by contractor Ferrovial Laing O’Rourke at their ‘Off- site’ manufacturing facility at Worksop and then ‘stitched‘ together in situ at Nine Elms.

The challenges of managing ventilation and smoke control were noted at both stations with provision for large fans and vent shafts. At both stations safety pits are installed in the ‘4 foot’ in the platform area with the new LU standard tube track Delkor baseplate assembly.

The PWI is grateful to hosts Jonathan Cooper (Project Manager) and Danny Owens (Project Engineer) of London Underground for this very special visit.

AUTHOR Photo 2: Battersea – on top of the station box. Paul Ebbutt PWI Vice President (South England & South West Wales Sections)

Professional Development Officer (South)

Site visits are great for building knowledge and CPD. If you’d like to organise or host one, please contact your Section Secretary.

Photo 2: Battersea – Scissors crossover

65 TECHNICAL ARTICLE

AS PUBLISHED IN The PWI Journal April 2020

VOLUME 138 PART 2

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