Construction has started on the first privately financed DBFO road in Wales, the 31.5km A55 in Anglesey. The £100M DBFO contract was awarded last December to UK Highways, the consortium of Hyder, Laing and Tarmac which two years ago took over maintenance of the M40 and last year completed the road's widening between Junctions 1 and 3A.
Under the new contract, UK Highways has three years to build the A55 dual carriageway trunk road from Llanfair PG on the east side of Anglesey to the port town of Holyhead on the west. It will then maintain the road for 30 years, and must hand it back to the Welsh Office with a residual life of a further 10 years. The consortium will receive payment from the Welsh Office in the form of 'shadow tolls', a payment scale based on the volume of traffic which uses the new road.
At the end of the construction phase, the existing A5 across Anglesey will be detrunked and will become predominantly a local access road. It is currently a notorious route for accidents, and local residents are, by and large, in favour of the new road being built to replace it.
There have been many proposals over the years to replace the A5, but until now the funding has never been available to take on such a major project. The Welsh Office is retaining Halcrow to ensure the details of the DBFO contract are met.
'There are four main parties, but everyone has direct contracts with everyone else,' says UK Highways construction manager John Gardiner. 'I'm here to act as the client and to liaise with the Welsh Office and its agent as any issues come up. Halcrow is not here as a traditional resident engineer - it is here to make sure all the requirements are met. We have arranged all the funding and we're taking all the risk from the Welsh Office, so ours is very much a client function, but we also have the Welsh Office as our client.'
The requirements of the DBFO contract involve more than 20 schedules which include the drawings, core construction requirements, insurance, payment terms and mechanisms for managing changes. The Welsh Office specified the footprint of the road and also undertook some public consultation before awarding the contract, but the detailed design is down to the Tarmac Laing joint venture.
The three-year construction window was scheduled to begin in April 1999, but UK Highways' concession bid was based on a shorter construction programme, and the JV was keen to 'hit the ground running', according to William Pacey, the JV's operations director. The most significant thing was in getting the design under way,' he says. 'That is the risk period for a contractor. Being design and build, until you have the drawings you can't do anything, so when we knew we were the preferred bidder we decided we had to take the risk and get the design started.' As a result, the new road should be finished by spring 2001.
A swift start was also vital to avoid disturbing the wildlife on the island. Gardiner says: 'This is a very ecologically sensitive area for nesting birds and fish, so it was very important to get in early.' The nesting season starts in February or March, so most of the major earthworks must be completed by the beginning of next year to avoid disturbing the sea birds. The JV has placed a one-year contract worth between 15% and 20% of the total contract value with earthworks contractor CA Blackwell. This contract has been set up as a partnering arrangement, which incorporates sharing of both risks and benefits. There is a total of 3.2Mm3 of earth to be moved, including 1.1Mm3 of hard rock, which is blasted to form cuttings. The design is based on a 'whole project' approach which balances the volume of cut and fill along the 31.5km route.
'We are working closely with Blackwells to look at the distribution of that balance,' says the JV's project manager Bryan Diggins. 'We get them involved in the design and if there are any changes they can share the benefit.'
Diggins has split the scheme geographically into four sections, with a section manager and team based in each. Section 1 starts on the east side of Llanfair PG where the new road splits from the line of the existing A5. This section includes several hard rock outcrops, one of which will be blasted to a depth of 17m to form the deepest cutting on the route.
Much of the blasted material will be used for aggregate in the surfacing, while other won material, including weathered rock, will go into a large embankment being built to take the road across the Malltraeth marsh. Band drains and stone columns are already going into this area to help cut down the settlement period for the embankment to just nine months.
This area is also particularly ecologically sensitive. There are two canals running through the marsh which cannot be cross-contaminated; ducks and oystercatchers nest here; crested newts and other amphibians must be translocated; and the contractor has to create new habitats for water voles. But, says Diggins, 'with all ecological and environmental issues, if you put your mind to it and manage it, then it can be done'.
Project director Richard Hughes adds: 'Ecology is a very very major part of the works and it has a major impact on the programme.'
Diggins says it is important to make good relationships with the bodies responsible for maintaining the ecology of the island, and to understand what they want. 'We have to work out how we can build the road and be mindful of the environmental issues,' he says, 'so we have got to understand the background.'
Section 2 runs west from the Nant Turnpike, where much of the traffic will turn off to Anglesey's 'capital', Llangefni. This section is mainly a series of small cuttings and embankments, but also has a population of water voles, whose habitat is protected. The contractor has had to catch the animals and translocate them to new river bank habitats off the line of the new road.
The third section takes in the inlet of the sea just east of Holyhead. The road runs on a large embankment and then a cutting before crossing the sea on a 1km long rock causeway parallel to the existing road and rail embankment. Some of the work here will have to be done under possessions, and the JV has developed a close working relationship with Railtrack to make sure it all goes smoothly.
Construction of the new road will give a colony of terns which live in the inlet a new lease of life. Their sand spit home had become accessible to foxes, which were killing the young birds. As part of the contract, the Tarmac Laing JV will create a new sand island where the birds can nest in safety.
On the west side of the causeway, the road goes into Holyhead and Section 4 of the project. Here, the work is completely different from elsewhere on the route, as it is the only urban section.
Diggins says: 'This is very much about logistics and planning. It is a very small section but there are a lot of things that have to be dealt with, particularly in terms of public relations. We will be working on bridges that are very important for the local community, and we have to maintain good access into the town and the port.'