Facts and Figures

Client
Transmanche Link

Period
1988-1990

Location
Folkstone, Kent

Contractor
Westminster Dredging Company Ltd

Channel Tunnel

The Channel Tunnel contract was a major project for Westminster Dredging in the late eighties and at the time was reported as the most expensive construction project ever conceived at more than £14 billion. The project was of major national importance in the UK and Westminster Dredging came forward with an alternative methodology, contributing substantial technical innovation and engineering, to both accelerate the onshore works and make a major cost saving to the overall scheme.

The work involved the installation of an 800m offshore submarine pipeline and a further, overland, 6.5km temporary pipeline, in itself a major undertaking, to deliver sandfill to a receiving area almost 70m above sea level. The routing of the pipeline required enormous efforts to obtain permissions at ministerial level to traverse mainline railways, major roads and motorways, military training areas and many other private interests. Several of these involved the construction of substantial, purpose built, bridges to carry the pipeline, river crossings and burials, – a far call from the usual run of the mill dredging contract.

The sand material was dredged from the Goodwin Sands, off the East Kent coast, and delivered to Sandgate, near Folkestone, from where it was pumped ashore through the temporary pipeline. After each delivery the transport water from each load was pumped back down the pipeline to the sea leaving the sand in a huge holding area for subsequent distribution across the Folkestone terminal site by the Transmanche Link consortium.

The material was delivered at a rate of some 120,000 tonnes per week and was so successful that the original quantity of 2 million tonnes was increased to over 6 million. It was estimated at the time to have saved approximately 200,000 lorry movements for the original quantity alone so by the time the project was finished there was a huge environmental benefit.

Although, Westminster Dredging Company finished its own work in 1990 the overall Channel Tunnel project was not completed until 1994 and, in the first 5 years of operation, it carried 28 million passengers and 12 million tonnes of freight.