Hewson Consulting Engineers have recently completed two projects with Conquip Engineering Group on a new hybrid excavation propping system, for a number of London basement schemes. Hewson aided Conquip with the design of a system that would be suitable for several applications on multiple projects across many sectors. Projects completed include a single level basement to the £150m, 53 floor residential tower at Canary Wharf developed by LBS Estates, and a double level basement for a 22 Storey Hotel on Commercial Road, Aldgate, developed by Reef Estates. Conquip have many more projects that are currently using this system, along with an exciting pipeline for 2018.

The system designed was lighter, using less materials and was easier and quicker to install, saving a significant time of the construction programmes. Careful detailing of the prop lengths, control of deflections, practical design and detailing of prop ends and housing for the jacks at the interface with secant piled wall corbels or capping beam levels, all proved significant. An installation methodology was drawn up by both designer and installer, that was straightforward, fast and economic, and gave programme saving on each contract.

Considerations were given to improvements, as the props move from project to project, loads, lengths, connection pieces and details were interrogated to ensure the best design and the best detail was chosen for this hybrid, reusable, system.

Conquip Engineering Group are based in Alton Hampshire where their state of the art manufacturing plant produces the props along with crane, excavator and forklift attachments. Having launched their range of trench shoring boxes, Conquip needed Hewson consulting engineers to respond quickly and efficiently as the props are reused from site to site.