Thames Tideway

Engineering excellence for infrastructure

At Conquip Engineering Group, we specialise in delivering innovative, end-to-end engineering solutions for unique project needs.

A prime example of our work is our contribution to the Thames Tideway project, a Nationally Significant Infrastructure Project (NSIP) improving the health of the River Thames by preventing CSO discharges. Our focus was on the Greenwich Pumping Station, where we designed temporary works for the connection culvert, a key component linking the existing Greenwich storm relief CSO to the new Tideway CSO.

This crucial task showcased our expertise and innovative approach in the face of complex infrastructure challenges.

Project overview: What were the design challenges?

Our temporary works design team was involved early in the project, working closely with Costain Vinci Bachy JV and Tideway teams, to ensure that we knew all the temporary works design challenges and any implications that the logistics and program would have on sequencing or overall design.

Here were the main challenges that our team identified:
1. High retention loads and complex shape leading to significant lateral loading in the waler.
2. Matching the profile of the retained wall, accounting for existing foundation elements as they were exposed during excavation.
3. Coordinating available openings for site lifting operations.
4. Connection of waler beams to the diaphragm wall (D-wall).

Overcoming the challenges with engineering

Through discovery sessions with the project team, we collaborated to uncover all the key challenges throughout the program of this complex project.
Using this information, we could start to overcome the challenges detailed above, here were our solutions:

• The unusual, retained shape combined with already significant propping loads, generated high lateral load in the waling beams. We developed prefabricated bolt-on shear keys into the piled wall, these ensured easier installation and removability, whilst also reducing the amount of ‘hot works’ required on-site.
• We designed a retaining scheme that splayed out at an angle to closely match the retaining wall shape. As works progressed, it was discovered that a number of existing concrete foundations adjacent to the excavation were not in the positioning or level originally considered. We coordinated with the site teams to reposition our propping and alter the load transfer mechanisms to avoid disruption.
• Prop location and spacing had to be carefully coordinated with the site teams to ensure sufficient openings were left for cranes lowering precast components for the culvert.
• Propping had to be kept at an offset from the D-wall face to facilitate site works. This led to the end length double-height waler beyond the props being potentially unsupported. We designed a bespoke connection to the face of the D-wall, coordinated with the site team and wall designer for imparting load onto the structure, and provided detailed installation sequences to match the tight tolerances on site.

Innovation in action: Redesign throughout the project

As is often the case with major, complex engineering projects, some challenges only arise once excavation or construction begins. Our team had to work closely with the project team to overcome certain challenges, such as logistics implications or methodology changes.

“We had a major design issue, which we didn’t foresee, we had new loads which we didn’t account for. In a really short time frame, Conquip designed a whole level of propping for us… which they manufactured and brought out to site, turned around in a fast timeframe… so it didn’t hold us back.”
Henry Wollmering | Project Engineer, Tideway

Collaboration and success: A testament to teamwork

Our success on this project was made possible through our close collaboration with Tideway and main works contractor, Costain Vinci Bachy JV. Regular meetings and effective communication allowed us to address challenges, share insights, and refine our temporary works design. We are grateful for the collaboration and support we received from Tideway throughout the process.

“We’ve got a number of different interfaces here. We’ve got the shaft team, we’ve got the CSO team. We really had to work with Conquip to work with our tight constraints, going back and forth to make site conditions work.”
Henry Wollmering | Project Engineer, Tideway

Keeping a major project on track with fast, collaborative service.

Our involvement in the temporary works design at the Greenwich Pumping Station exemplifies our commitment to providing cutting-edge solutions and delivering exceptional results. By combining our deep technical understanding, innovative approach, and ability to design and manufacture in-house, we successfully supported this construction phases of the Tideway super sewer project.