Press Releases - New Tyne crossing benefits from Sirius expertise 

Sirius Group is using its expertise to help on of Britain’s biggest transport infrastructure projects.  Construction of the New Tyne Crossing - a second vehicle tunnel under the River Tyne in Newcastle – involves dealing with an area of contaminated riverbed sediment found on the exact line of the new tunnel.

Sirius reduced the scheduled drilling works to obtain samples for chemical analysis from two weeks to four days, and is also providing earthworks and enabling services to the main contractor, Bouygues Travaux Publics (UK branch), in support of the tunnel-construction works.

Part of the new Tyne Crossing will be constructed using immersed-tube technology in the river section, which involves dredging a deep trench in the rover bed.  Sirius was brought in by the main contractor, which needed a chemical analysis of the river sediment to allow waste classification before dredging could take place.

This classification was complicated as Bouygues was considering disposing the dredgings at sea, while still retaining the option to put them in landfill.  With that in mind, the chemical testing was undertaken in line with the Centre of Environment, Fisheries & Aquatic Science, as well as the more common waste-acceptance criteria tests of the UK Waste Regulations 2005.

Sirius decided that traditional cable-percussive drilling would be the most suitable and costs-effective method of obtaining samples from the contaminated area for analysis.  As part of this, Sirius liaised with the Port of the Tyne Authority and the jack-up platform operator to develop a safe, working strategy for the works, and minimise disruption to the Port of the Tyne and river traffic.

A total of eight boreholes were drilled.  Initially, due to the complex nature of moving and setting out position of each borehole from a jack-up platform, the drilling works were scheduled to take two weeks.  However, forward planning – including detailed method statements for 3D surveying each borehole position and consideration of the tidal variation – meant that drilling was completed within four days with a cost-saving passed on to the client. 

The new tunnel is due for completion in December 2010.  The existing one will then close for refurbishment, with both tunnels expected to be open for traffic in December 2011.

Extract from press comment in...

• Geo-drilling - May 2009