Amey Case Study
Detailed Tunnel Inspections (Structures)
PROJECT NAME: Detailed Tunnel Inspections (supporting Amey on the CEFA contract)
NETWORK RAIL ROUTE(S): LNW
SERVICES: Detailed Inspection of Tunnel and associated structures using rope access
During CP5 our company supported Amey in the completion of detailed inspections of a number of tunnels and associated structures across LNW route. Our predominant role in this works was specialist access, providing STE6 examiners who were IRATA certified to complement Amey’s resources, as well as providing our IRATA L3 supervisors.
We planned and executed the works providing all equipment and personnel required for safe access to the tunnel shafts and portal structures. Our examiners also undertook a number of tunnel bore inspections with Amey as part of this works, predominantly from MEWPs. Tunnels ranged from a few 10’s of yards long to one that was 3miles 0880yards long with associated shafts over 200m deep!
Before project start, we conducted a thorough desk study review along with site reconnaissance to establish a programme of works taking account of access and any enabling works required. This was fed back to our client. The works were led by our client with WPP, and TBS produced by them with our input. All site work was conducted in conjunction with Amey personnel.
Tunnels inspected as part of the works included sections that were lined and unlined, cut and cover as well as bored. Some of our STE06 examiners are also geotechnical engineers and have experience in conducting UTGRA’s.
All the structures were inspected during night-time possessions, with most of the enabling works conducted during the daytime with no disruption to normal traffic.
Enabling works included vegetation clearance around shafts, the installation of anchor bolts, clearing of debris, removal of fence panels as well as gaining access through 3rd party land.
During the tunnel inspections we identified, located, and recorded defects on major and minor elements collecting enough data to enter into the Tunnel Examination Report and TCMI. Bricks and masonry were tap tested for hollowness, missing mortar, cracks identified as well as out of plumbness, water ingress, missing bricks, deformation, and drainage features.
Some of the deep shafts required us to use different techniques to undertake the work in as a safe and efficient manner possible. We utilised many different types of anchorage and edge protection, with all the rope ‘rigged to rescue’. Powered winches and ascenders were used in several of the shafts. Some of the works was considered as a confined space making use of our medium risk confined space competencies.