COWI tunnel engineer is a finalist in the british tunnelling society's harding prize 2018

Press Release: Senior Civil Engineer, Gerard Quigg, is one of four finalists this year for his paper 'Battersea Cable Tunnel: Powering a Renaissance at Battersea's Iconic Power Station'.

06.04.2018

The Harding Prize competition is named after Sir Harold Harding, the founder Chairman of the British Tunnelling Society, and is open to all tunnelling engineers aged 33 or below. It aims to encourage young tunnel engineers to write about work in which they are involved, focusing on their personal involvement and contribution. Entrants must write a paper on any topic dealing with tunnel design, construction or consultancy, considered of interest for the tunnelling industry.

Gerard's contribution to the Battersea Cable Tunnel project was wide-ranging, with responsibilities including: leading the approvals process for all third party assets that the tunnel passed under; designing the structural elements of the access shaft and Launch tunnel; and providing design assurance to the project by fulfilling the role of Monitoring Engineer during the tunnelling works. 
A panel made up of BTS members examined all papers, and chose Gerard as one of four finalists who will present their papers at the April BTS Meeting. The judges will then select a winner taking into account their written paper, oral presentation and how questions were handled.

The winner receives a copy of Sir Harold Harding's book "Tunnelling history and my own involvement", a certificate and £500, and all finalists' papers will be published in the Tunnels & Tunnelling journal.

BATTERSEA CABLE TUNNEL

Battersea Power Station stopped generating electricity in 1983 and a new electricity substation is being built to help distribute power to homes and businesses across the new neighbourhood. The substation will be connected to the existing electricity network via a new underground tunnel.

To reduce noise and disturbance during the tunnelling works, the contractor set up their site within an existing warehouse. COWI assisted during conversion of the warehouse and installation of a Gantry Crane.  A 30m deep, 7.5m diameter access shaft, and sprayed concrete lining (SCL) Launch tunnel were constructed on the substation site in Battersea, so that a Tunnel Boring Machine (TBM) could be used to construct the new 300m long cable tunnel.

COWI designed the temporary works required to launch the machine, and as 2017 BTSYM Schools and Universities Chair, Gerard led a community engagement project with a local school to name the TBM. Pupils from the local Oasis Academy secondary school named it after the prominent English space scientist, Maggie Aderin-Pocock.

It took miners 11 weeks, using the open-face shield TBM to build the tunnel through London clay, some 20m below ground. A temporary railway took spoil back to the surface where it was used for land reclamation, rather than going to landfill.

The Junction Chamber was the key project risk. It connects the new tunnel to the existing wedge-block cable tunnel 20m below ground level. The TBM was stopped 4m away from the existing tunnel where it was disassembled and removed through the tunnel and shaft, leaving the open-face shield in place.

The perpendicular connection was formed by excavating around the existing tunnel using traditional 'timber heading' techniques. This is a temporary works method, where a small timber lined tunnel is excavated by hand. It supports an excavation that is later infilled with permanent concrete. The soil was excavated by miners using a hand-held pneumatic tool for clay excavation in 1m lengths. A timber frame was then installed to support the ground load. Following completion of the reinforced concrete wraparound, the connection was made by removing precast concrete segments from the existing tunnel.

COWI was the contractor's permanent and temporary works designers for the project; led by UK Power Networks, and undertaken in partnership with Alliance contractor Clancy Docwra and tunnelling specialists Joseph Gallagher Ltd.