In April 2004 the Highways Agency appointed Nuttall and Capita Symonds to work on two Early Contractor Involvement (ECI) projects between Cambridge and Bedford worth a combined £112M.
In effect, it created one project design team with two teams on site, and the approach has meant both are likely to finish well ahead of schedule.
The £57M A421 Great Barford Bypass, north east of Bedford, was the first project the design team worked on. It immediately set about revising plans submitted to the public inquiry, starting with the over bridges.
'The proposal was that they would be in situ concrete bridges, ' says Nuttall Great Barford project manager Simon Whalley. 'As part of the ECI and because of Nuttall's previous experience of working with Capita Symonds, we opted for a much simpler approach using a steel composite with lot of precast concrete elements.'
Work began on site in October 2004 and will be completed ahead of schedule in August.
The second scheme is the £55M A428 Caxton Common to Hardwick improvement. It is now following on 10 months behind and will benefit from lessons learned at Great Barford, says Nuttall project manager Adrian Savoury.
The project will transform 7.7km of the A428 to dual carriageway between Caxton, east of Bedford, and Hardwick, west of Cambridge and will accommodate the predicted rise in traffic between the new town of Cambourne and Cambridge.
Using the same design team as Great Barford, Savoury says that while the team worked on the bypass first, Caxton was always under consideration.
'We were all sitting there thinking about both schemes at the same time, ' he says.
This, for example, meant Caxton is also using steel composite over bridges and that, due to the two sites' proximity, a lot was known about Caxton's geology very early on.
One section of the Caxton scheme that beneted both from ECI and the relationships established by Great Barford was the underpass at Hardwick Junction (see diagram).
The underpass is an 8m deep open excavation and the Agency envisaged that the contractor would build a diversion before digging under Scotland Road, the main road into Hardwick.
But this meant Nuttall redirecting telephone lines, power cables and a water main that runs along Scotland road.
Savoury and his team worked on a way of avoiding all this work and came up with a solution that reduces the underpass's width by building a single, rather than dual, carriageway on piled foundations, shifting the northern roundabout 25m west.
'We have then got the bridge off of the footprint of the existing road, ' says Savoury. 'This allows us to leave the trafc on Scotland Road. We can then build the deck, divert the trafc onto the new road and take out Scotland road.' Savoury says this approach will save the project time and money, nishing a month or two ahead of its Autumn 2007 completion deadline.
Emergency escapes on the Great Barford bypass Two weeks ago thousands of motorists were stuck in an eight hour traffic jam on the M25 caused by an intense petrol tanker fire (News last week).
The jam stretched for 29km but stranded motorists could not be diverted off the road because that section of the London Orbital has no emergency cross-over points in the central reservation.
Highways Agency officials hastily announced a review emergency access to the motorway network as a result, but at Great Barford they are one step ahead.
Nuttall has installed two emergency access gates on the 7.7km route on the advice of the Agency's Managing Agent Contractor Carillion URS.
The gates are 17m long steel box beams that have hidden wheels requiring only a ratchet spanner to lower them into position beneath the steel barrier. Once lowered, they can be pushed by hand intothe open position to divert trafc onto the opposite carriageway. This can be done, according to manufacturer Asset International, by a single operator in ve minutes.
There are also plans for one gate to be installed on the Caxton improvement scheme.