Bridgeway Consulting Ltd (BCL) knew that gaining its Principal Contractor Licence in 2013 would be a gateway to a unique status within the rail industry…
BCL could now position itself as a contractor specialising in pre-construction information gathering capable of planning and executing the most complex of scopes in the most challenging of environments. From our initial audit as part of the Birmingham Re-Signalling Project Phases 4 and 5 Ground Investigation and Topographical Survey (which we passed with zero NCR’s and only three minor observations) the jobs we were asked to put our licence to were gaining in their complexity and their prestige. We have acted as PC now on multiple large-scale jobs for a variety of clients including Network Rail, Mott MacDonald, WSP, and Arup to name but a few with a reputation for delivery and success.
The culmination to date of the evolution of BCL as a PC specialising in the acquisition of pre-construction information has been the successful bidding and ultimately delivery of the investigations for the enabling works at two of the proposed HS2 hubs in Euston and Crewe. Both sites presented a challenge for various reasons but with the collaborative approach and clear thinking at planning stage BCL are known for, all problems to date have been overcome and the required information has been gained for our clients.
The scope for both hubs has been commensurate with what would be expected from the proposed reception stations for the largest infrastructure project the country has seen in generations. Multiple disciplines had to be brought together both internally and from external sources and access carefully managed through the rigorous 019 planning process combined with strong stakeholder management to successfully deliver the scopes required by the client.
The first step was to embed our experienced PM in with project team to ensure someone was on hand to answer queries, be the main point of contact and be the person on the spot to run the show.
The embedding of staff within the project team was an approach strongly favoured by the client who found having the expertise our BCL staff had on hand invaluable in the complex planning and delivery of the works. A strong supply chain built up over the previous years of delivering infrastructure project placed BCL perfectly to put together a robust plan and bring partners who shared risk and were back to back with BCL on an assurance and accountability level.
Complex ground investigations
One of the most complex areas to deliver has been the ground investigation. With emerging technologies and newer ways of in-situ testing and monitoring the scope had been developed to ensure information gleaned was fit for purpose in particular for the design of a 27 metre high retaining wall on the west side of the Euston throat to replace the current Victorian structure currently in-situ. With working constraints and even tighter time constraints for mobilising and working trackside the logistics of such an operation required the considerable skill and experience of the project team to deliver.
The main intrusive scope for Euston comprised of the following:
• Structural coring of the existing retaining wall
• Dynamic probing to determine the extent of foundations of said retaining wall
• Window sampling to eight metres with follow on dynamic probing to ten metres trackside
• Window sampling to eight metres with follow on dynamic probing to ten metres on platform
• Cable percussive drilling with rotary follow on to 45 metres trackside
• Cable percussive drilling with rotary follow on to 65 metres trackside
• Rotary percussive boreholes trackside to 65 metres with pressure metre testing and vibrating wire piezometers installation
• Rotary percussive boreholes on platform to 68 metres with pressure metre testing with vibrating wire piezometer installations
• CPT to 20 metres trackside with mag cone
• Trial pitting trackside
• Trial pitting on platform.
As previously mentioned, the above scope would be a challenge in greenfield or brownfield setting, when you add in keeping one of the busiest stations in London running while working, stakeholder management became key to ensure the works went as smoothly as possible. A very accommodating station team assisted with access and by working closely with the in-situ S&C Alliance, we were able to maximise access opportunities. The challenge of sinking a cable percussive hole on the end of platform 16, between live overheads requiring isolations and complex in-situ testing was still not an easy one but by breaking it down into individual elements BCL ensured all parties were informed, knew their role, and what to do and when to ensure successful delivery.
The on-track works required a great amount of collaboration between BCL and our delivery partners to successfully deliver on a very technically challenging scope. As businesses mature, they see the value in collaboration and for this project our delivery partners Omnia Environmental, In-Situ Site Investigation, ADP Group, Borehole Solutions, and Terradat UK all had key parts to play augmenting BCL’s internal capability to undertake these types of works.
The working constraints of the site (drilling with lines open to traffic at the base of a 27 metre retaining wall with foot access only) meant there had to be some creative solutions including a pumping system to provide 10,000 litres of water every 16 hours of working from road level to the base of the wall where the drilling site was located. Combine this with the stabling of RRV’s at the site, three rigs working and moving with associated equipment and 2No PASMA towers with coring crews meant coordination was key.
As with so many projects now, monitoring post site works is key and at the time of publishing the monitoring phase of the works at Euston is coming to an end. For the duration of the project we have had a mixture of systems employed from data enabled wireless systems for piezometers, noise, dust, and vibration to conventional monitoring of ground gas and water.
As BCL has the capability to conduct training in all safety critical competencies our staff are multi-skilled with our technicians and engineers being either Individual Working Alone (IWA) Controller of Site Safety (COSS) including IWA or SWL1/2 (Safe Work Leader) incorporating IWA this means that they can deploy with the relevant safety and technical knowledge to undertake the task in hand safely either as an IWA or as part of a two-person team to undertake monitoring duties to the highest standard.
The successful delivery of one project and successful delivery to date of the second project is testament to BCL’s can-do proactive approach combined with extensive technical and railway knowledge combining to form a delivery partner to clients they have fait in and are happy to work with. From Trainee Technician to Project Director each member of BCL’s staff is committed to delivering a quality product to the highest standard in the safest manner possible which as our clients’ attest is what makes the company that it is.
Tel: 0115 919 1111
Email: [email protected]