Project Title



Delivering a Combined Sewer Outfall (CSO) Shaft and a SCL connection was a challenge but despite some setbacks the team did an exceptional job in delivering quality works both on time and on budget.


Thames Tideway
Main Contractor:
Ferrovial Laing O'Rourke
69 weeks
  • Delivered on time and delivered on budget;
  • Multiple challenges overcome through excellent team attitude and a positive client relationship,
  • Featuring the longest Sprayed Concrete Lining (SCL) drive on the entire Tideway scheme, to date.

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Project Overview

JGL were commissioned by main contractor FLO to deliver a CSO (combined sewer outfall shaft) alongside an SCL connection tunnel into the Tideway main drive.

Without the skills and commitment from our brilliant team along with the SCL mix design – we simply would not have been able to consistently pump from a single point onto the surface.


The biggest challenge faced on this project was in the 250m long connection tunnel. The diameter and length of the drive meant that we had to be very selective with the choice of plant used to complete the drive. Initially, the Wimmer Blue Badger was used to excavate the first half of the tunnel and then we reverted to the SPA Schaeff 112 for the second stage.

The second challenge of getting concrete to the spraying robot was significant considering the distance the material had to travel from the silos on the surface (300m). Initially, concrete remixers were considered however, the diameter of the tunnel eliminated this option as the remixers simply would not fit. That left the option of pumping from the surface which introduced the risk that the Meyco Suprema pumps might not have capacity to pump the concrete the required distance. To overcome this, we had the backup plan of stage pumping with additional pumps and the fabrication additive storage gantry.

The JGL team had the right mindset to overcome the challenges during the completion of the project. Finding new ways of working and still delivering the project to a high standard.

Added Value

To eliminate several risks associated with fixing the cut and bent reinforcement in the CSO shaft base slab, we approached Express Reinforcement (ER) to discuss the option of prefabricating the base slab reinforcement. ER then redesigned the reinforcement, which introduced multiple benefits such as eliminating key risks during the implementation phase in addition to an accelerated installation time-frame.

Community Involvement

A fundraiser was led by the SCL Supervisor at (Falconbrook Pumping Station) FALPS to help raise money for the local children’s nursery located next to the site. With residents and families on the estate being affected considerably by Covid-19 – the idea was to raise money to go towards Christmas presents for every child attending the local nursery.

£600 was collected by the project team, with £150 being donated by JGL.

To hear about our experiences and how we can help you.

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