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A widening vocabulary

Concurrency, incubation, surgeries - unlikely words like these describe why Highways Agency engineers are sweating over the widening of the M2. Ty Byrd reports.

Preparations for the M2 widening project - at £200M set to become Britain's biggest current roads scheme - are drawing to a close, with tenders due in next month. But pressure is not letting up on the client, due to a unique set of circumstances that are adding to the lexicon of construction planning. The project is a remarkably complex one, with vital elements of strategy whose description and effects require new words and fresh meanings.

'Concurrency' is one of these words. The M2 is one of Kent's two coastbound motorways and the stretch to be widened is the heavily trafficked, two- lane Medway Towns bypass section, which runs south and eastwards from the motorway's beginning at Strood, over the Medway and up across the face of the North Downs to Gillingham - Junctions 1 to 4, to be exact.

From Junctions 1 to 3, the widened M2 will be accompanied by the Channel Tunnel Rail Link which, give or take a few metres, will run parallel to the motorway at this point in its journey between London and the coast.

Construction of the two schemes will overlap, which is why the Government - mindful of the political difficulties of getting a motorway widened, let alone a new railway built - insisted a few years back on concurrency - the running together as far as possible of the two projects.

This policy first manifested itself during the parliamentary process in the early to mid-1990s. In effect, Part 2 of the railway link's hybrid bill covers all the works for the M2, all the necessary compulsory purchase powers and so on.

As official documentation put it in 1994: 'Having both schemes in the Bill enables concurrent construction to be employed, to reduce the period of inconvenience and disturbance, and provides the opportunity to integrate the two schemes in the most economical and environmentally satisfactory way.'

Colin Chadwick is the Highways Agency's project manager for the M2's widening; he took up his role well before Royal Assent was granted for the CTRL bill in 1996.

A civil engineer as well as civil servant, he is too discreet to describe the consequences of Government's assurances on concurrency as 'nightmarish'. However, he does acknowledge that they have made his life, and those of his Agency colleagues and helpmates at consultant Maunsell 'rather more difficult' than would otherwise have been the case.

'Mitigation for the motorway works could not be looked at in isolation from that for the railway, and vice versa,' he says. A joint approach made good sense. 'A Memorandum of Undertaking exists which ensures that we are locked into the consultation process, consulting local authorities, other public bodies and the public itself in parallel with our counterparts at CTRL.'

The comments of all interested parties have been listened to over a considerable period of time and taken into account during preparation of the motorway project's tender documents.

So, too, were the CTRL project's needs and requirements. Extensive meetings have taken place between Chadwick's team and Rail Link Engineering, CTRL client Union Railways' design specialist, to discuss how best to design and build each scheme with the other very much in mind.

The Agency's M2 works involve turning some 16km of dual two lane carriageway into dual four, or dual three with a climbing lane, using parallel widening techniques; greatly modifying the existing Medway bridge to carry coastbound traffic only; building a second crossing for London bound traffic; extensively rebuilding two major junctions including the notoriously confusing Junction 3; and carrying out comprehensive landscaping to reduce the impact of the whole scheme.

The CTRL works include a new permanent way running above ground adjacent to the M2 for much of the distance between Junctions 1 and 3; a bridge across the Medway just upstream of the M2's new bridge; a tunnel where the line approaches Junction 3 and turns south towards Ashford; close encounters with the M2's two big new junctions; and landscaping, as above.

'We've worked hard to blend what we are going to do and the way we will do it with CTRL operations,' Chadwick says. 'The idea has been to maximise the potential mutual advantages while minimising environmental and social impact.' There is also an essential, practical reason for both parties knowing what the other is up to. The two new Medway bridges - both over 1km long and 30m high - will be built within a very few metres of each other and the existing crossing.

So concurrency is the name of the game. A good example, Chadwick says, is the way spoil from CTRL's tunnelling operations will all be used as embankment fill, a significant amount going into the widened motorway's embankments. While some of the spoil will go directly into earthworks near the railway's portal by Junction 3 (known as the London portal), most of it will come from the further-away country portal and be trucked to site. Lorry movements for this exercise and all the others which involve public highways have been identified and rationalised.

Concurrency planning is aided by the time lag between the two schemes: CTRL began work last October; the M2's 42 month widening contract will be let this November. 'We'll be more or less a year behind and it's got to stay that way. We cannot afford to slip,' Chadwick says.

The workload of the Agency's comparatively small team has been heavy, leading up to and beyond the issuing of tender documents. The M2 widening has been designated as one of chief executive Lawrie Haynes' 'incubator projects', in which innovation is to be encouraged and nurtured. Chadwick cites lightweight, low-intrusion sign gantries as one item for possible incubation. Others are automated penstocks to hold back spillage, bridge enclosures of GRP to cut maintenance and reduce risk to maintenance operatives, and low noise road surfacings.

The contract is also design and build, which has brought its own problems prior to contract award. Chadwick and his colleagues produced an illustrative design which outlined what was required and set the landtake footprint, for example; but it is down to the successful bidder for the work to fill in the detail. But how to get sufficient information across to the tenderers for them to produce detail designs? Indeed, how to compile a list of tenderers with the potential to carry out the work to the Agency's liking?

'The toughest thing we've had to do so far is select companies for the tender list,' says Chadwick. 'There are so many things to be understood by potential bidders beyond simple motorway widening: the association with the CTRL, all the interfaces, the need for consultation with local authorities, community liaison at a high level, the special needs of the environment.'

The M2 between Junctions 1 and 4 acts as a boundary separating the Medway Towns to the north and east, and open countryside to the south and west. Much of this countryside falls within the Kent Downs area of outstanding natural beauty. Hence, being able to deal competently with environmental matters is of utmost importance.

Nine potential tenderers were invited to St Christopher House in Southwark Street, London, to attend presentations on the engineering aspects of the M2 widening, and on the environmental aspects. This proved a good way of establishing a level playing field, according to Chadwick.

Six were asked back and interrogated about how they would take the scheme forward. Unusually, local environmental health officers from surrounding districts attended the meetings to listen in, and later give their opinions. The candidates were then assessed and the four highest ranking invited to tender - all deemed to be the kind of organisation the Agency would be happy being involved with in a partnership arrangement.

For the record, the four are Costain/Skanska/Mowlem with WS Atkins; Amec/Alfred McAlpine/Mott MacDonald; Tarmac/Symonds Travers Morgan/Robert Benaim & Associates; and Autolink, comprising Amey, Sir Robert McAlpine and Taylor Woodrow, with Scott Wilson. Their invitation to tender was made last February.

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