Tunnelling begins on London Power Tunnels Phase 2

6 July 2021

Tunnelling has started on the second phase (LPT2) of National Grid’s £1bn (US$1.38bn) London Power Tunnels project as TBM Edith installs the first segment rings at the New Cross site, south of the River Thames.

The start of tunnelling constitutes another milestone for the 32.5km-long LPT2 project and follows the arrival of the TBM to site on 14 May 2021. Boring at average depths of 30m below the streets of South London, the machine will create 3m-diameter tunnels to house new electricity transmission cables for three new circuits seen as crucial to London’s future electricity supply. Shafts will be around 15m in diameter and between 30-40m deep; those which will not be required to provide access or ventilation will be backfilled.

In December 2019, the Hochtief Murphy Joint Venture (HMJV) was awarded a contract worth around £400m (US$554m) to deliver the tunnelling, shafts and headhouses for LPT2. As 50-50 partners, the two companies have a strong track record, having delivered projects such as the Channel Tunnel Rail Link (C320) and the Crossrail Thames Tunnel project (C310).

The six-year LPT2 project is designed to minimise disruption to Londoners as there will be no need to dig up the existing 50-year-old cable infrastructure, now reaching the end of its life. Construction began in March 2020 and has continued through Covid-19 lockdowns.

Scheduled for completion in 2026, the three sections of LPT2 are:

Circuit 1: Wimbledon to New Cross, 12km – operational by 2025.
Circuit 2: New Cross to Hurst, 18km – operational by 2026.
Circuit 3: Hurst to Crayford, 2.5km – operational by 2026.

The first phase of the project, the £1bn LPT1 north of the Thames, was constructed between 2011 and 2018 and involved 32km of tunnels and two new substations.