Job Description

Client: Metropolitan Police Air Support Unit
Main Contractor: Walker Construction Ltd
Main Sub Contractor: Tom Blackwell Ltd
Quality Stabilised: 6500m³

Project Overview

Lippits Hill is home to the Metropolitan Police Air support Unit the ‘Sky Cops, as featured on the BBC programme of the same name. The two Eurocopter EC145 choppers patrol the air over Lodon, providing assistance to the ground patrols.

Furthermore, each time they take off, the helicopter pilot has to perform a number of checks to ensure that the aircraft is fully operational. These checks have to be done whilst hovering above the relatively small take off pad.


Scope of Works

Beach was called in to assist with the construction of a brand new runway. This was to enable the pilots could land safely on in the event of an emergency. The material on site was silty sandy clay. While it had reasonable strengths, an elevated sulphate spike in one of the trial holes meant Engineers, Scott Wilson, trialled the material with Quicklime and GGBS (Ground Granulated Blas Furnace Slag). Furthermore, as the results proved positive a mix design of 3% Quicklime and 3% GGBS was agreed.

In order for the full depth of the runway to be treated. In addition, Beach suggested to the Client that the entire formation be dug. Then placed in 3 separate treatment areas adjacent to the new runway. Consequently, this enabled us to increase production outputs as the earthworks plant were able to pick up the treated material and place it in the areas that had been bench cut, without having to avoid stabilisation plant and vice versa!

Working for Tom Blackwell Contractors of Essex, Beach successfully carried out the stabilisation of 6500m³ of material, exceeding the Clients expectations. Finally, testing was carried out in accordance with SHW Series 800 Earthworks, Class 9G.