BMB Turnouts and crossovers

Manufacture, Assembly and installation of Rail Turnouts and Crossovers For Thames Tideway Tunnelling works

Customer: BMB Joint Venture (Tideway West)

Year of contract: 2019

Value: £400,000

Site: Carnwath Road Site – Thames Tideway West main Works

The Opportunity

As part of the requirements for construction the Thames Tideway Western section Tunnelling works, a rail system is required for the transportation of materials to and from the TBM. At certain points in the tunnel the transporting trucks need to pass by one another and cross. Due to the shape of the tunnel the Turnouts and Crossover sections that allow this passing are elevated up from the tunnel invert to increase width and passing space. To achieve this elevation a temporary steel structure is required to be manufactured and constructed to sympathetically load the tunnel walls using cross beams with curved end plates and decking. Each beam is shaped to gradually elevate the track level from the invert to the level required for passing and crossovers.

An enquiry was sent for the manufacture and assembly of these Turnouts and Crossovers which fortunately we were successful in winning, due to our ability not only to manufacture the steelwork but also assemble in time for the planned tunnel machine shutdown and commercial competitiveness of our submission. Fundamental to the success of this project were the following key achievements;


  • Efficient and timely procurement from the supply chain.
  • Design and detailing checks of client’s drawings. This involved laying out of every beam to ensure errors in the original design were caught before manufacture. Four such significant errors were caught.
  • Optimised manufacturing techniques that include efficient usage of internal CNC cutting and drilling equipment.
  • Production line mentality and planning
  • In house already developed manufacture and weld procedures.
  • Good communication links with client to resolve TQ’s.
  • Organised production planning both in manufacture but also with assembly team and the client.


It was agreed that due to the size of the assembled modules they should be built up at a port which is feeding tunnel segments to BMB. We visited site and agreed with the port owners where and how we would facilitate the build-up requirements. Fundamental to the success of this build up section were the following key achievements;

  • Cooperative nature of Port and PSS in achieving common goal.
  • Understanding of the needs of a site build up.
  • Mobilisation speed.
  • Already obtained skills and qualifications for lifting, welding, setting out and safety.
  • Workforce flexibility.
  • Production control and issue preparedness.

The Solution

Power System Services planned and executed the manufacture of the steelwork in conjunction with the site assembly team and the client to ensure Tunnelling time was optimised and the modules arrived as planned for installation. We deployed a well-trained team to the assembly site and then subsequently to the tunnelling works site who had a wealth of experience in similar projects and had key targets to achieve. The contract works were phased in such a way that our contract was completed on time, without any incidents and to a high quality of workmanship.

The challenges faced during significant not least because the very tight programme, access and logistics.

Power System Services were commended on;

  1. Attention to safety.
  2. Quality of Workmanship.
  3. Attention to detail and problem/ issue solving.
  4. Site specific safety from the system considerations.
  5. Preparedness to work outside of usual working hours to accommodate others.
  6. Timely execution of the works.
  7. Team player.
  8. Cooperation with other works as required.

Power System services as installation contractor on this project worked with the client with a Common goal, helping develop specifications and inventory lists for maintenance and future needs, whilst understanding budget constraints.

The project was concluded safely, profitably, on time and to the specified standards.

Additional Project Images

References are available on request.