MECHANISED TUNNELLING | BTS HARDING PRIZE COMPETITION 2025
TBM TRANSITION THROUGH KIDBROOKE SHAFT
The Harding Prize Competition is named after the founder of the British Tunnelling Society, Sir Harold Harding, and is for entrants under the age of 33. Shortlisted papers were presented to the BTS evening meeting on 20 March, at the Institution of Civil Engineers, in London.
Sid Kaul, Tunnel Engineer from the Murphy Group, working with Hochtief-Murphy Joint Venture on the London Power Tunnels Phase 2 Project, was winner in the 2025 Competition with a paper entitled ‘TBM transition through Kidbrooke Shaft’
ABSTRACT This report explores the transition of the tunnel boring machine (TBM) through the Kidbrooke Shaft as part of the London Power Tunnels Phase 2 Project - Package 2 Tunnels & Shafts. It highlights key engineering challenges, maintenance interventions, and design modifications implemented to ensure a seamless TBM passage. The paper also discusses lessons learned and innovative solutions that contributed to the success of these works.
INTRODUCTION National Grid’s London Power Tunnels Phase 2 Project aims to enhance the electrical grid’s reliability by constructing 32km of underground tunnels to house high-voltage cables. The scheme is split into several packages, of which Hochtief-Murphy Joint Venture (HMJV) were contracted to deliver two: Package 2 Tunnels and Shafts; and, Package 5 Headhouses and Mechanical & Electrical (M&E). The project included five tunnel drives undertaken
from three drive sites: Kings Avenue, New Cross, and Hurst through the full range of the South London geology, with the New Cross site being unique as it serviced two drives extending west and east simultaneously. The New Cross east drive covered 11km and accommodated significant engineering challenges. As part of the wider permanent operational
requirements of the scheme, an intermediate shaft was constructed on the New Cross east drive, at Kidbrooke, approximately 7km from New Cross. To ensure the TBM operated efficiently over this 11km-
Above: TBM breakthrough for transition through Kidbrooke intermediate shaft on London Power Tunnels Phase 2 Project - Package 2 IMAGES COURTESY OF HOCHTIEF-MURPHY JV
10 | July 2025
long drive, the intermediate shaft at Kidbrooke enabled crucial maintenance activities and helped to ensure smooth tunnelling progress. Maintenance tasks at the shaft included cutterhead tool replacement, tailskin brush replacement, and screw replacement following the TBM’s breakthrough at Kidbrooke.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45
