Going underground to prop 60-metre vortex channel on Tideway project

Tideway, London

Project Overview

Location	Tideway, London
Sector	Water
Products	Mass 50 Mat 125 Hymat Jacks

Designed to reconnect London with the River Thames, the multi-billion Tideway project features a complex series of construction works all over the city, each requiring a unique temporary works solution. One such example is the temporary propping solution at the King Edward Memorial Park Foreshore site, which saw us take our bespoke freestanding solution 60 metres underground in order to help construct a key piece of the infrastructure.

The challenge

Addressing London’s sewer capacity challenge

The Tideway project is delivering a new 25km super sewer beneath the River Thames to relieve pressure on London’s ageing sewer network and reduce sewage overflows during heavy rainfall.

Supporting complex shaft construction

At the King Edward Memorial Park Foreshore site, a 60m-long vertical vortex channel was being installed within a deep tunnel shaft, requiring a bespoke temporary support solution during construction.

A precise temporary works solution

We designed and supplied a propping system to securely support and accurately position the vortex tube while the secondary shaft lining was cast, providing a faster and more efficient alternative to traditional concrete plinths.

Our solution

We were contracted to design, supply and install the scheme, with the final design featuring Mass 50 and Mat 125 props and Hymat HM100 Jacks. Once the propping tower was installed and the vortex tube was in position, the Hymat jacks were then used to make any final adjustments to the positioning, taking into account any deflection or movement.

Tim Delplanque, Site Agent for CVB Joint Venture, commented: “There were numerous challenges on the project, which we worked closely with Mabey Hire on to overcome. One was the time constraints. Only once the temporary propping support scheme had been completed could we proceed with the installation of the vortex tube and the rest of the shaft construction works. Fortunately, Mabey Hire was able to prefabricate and pre-assemble a large percentage of the propping equipment, which enabled a faster assembly process on site at the shaft.”

View Mass 50

Grahame Duffy, National Account Manager at Mabey Hire, added: “First of all, we had had to consider how we would transport the propping equipment down to the bottom of the 60-metre shaft. Then, it was a matter of working within the small base of the shaft to assemble and install the temporary propping scheme. Given the site constraints, it required a careful sequencing of the works – for example, once we had built one part of the system, we would have been unable to access other sections.”

“This is where our in-house installation capabilities really came into play, with our install team working closely with our field engineers to ensure the installation process went as smoothly as possible.”

Get in touch

“Mabey Hire were the only temporary works provider with both the equipment and the engineering capabilities needed to deliver the works safely and efficiently.”

Tim Delplanque

Site Agent, CVB Joint Venture