Train trench ready for big dig

Contractors are preparing to start the big-dig phase of a $160 million railway trench through the heart of New Lynn.

After spending more than six months sinking giant retaining walls along each side of the planned 1.1km trench, they are preparing for excavation trials in the next few weeks on the ground between them.

Ontrack project director Ted Calvert hopes digging out about 100,000 cubic metres of predominantly clay can start next month so the trench can be completed by Queen's Birthday Weekend next June.

He said yesterday that although much of the work had been largely invisible to the public, the overall project was about 50 per cent complete in budgetary and physical terms.

The completed concrete northern retaining wall, on which trains are running until the trench is ready, is supported by deep steel piles for extra strength for a bus interchange on the surface.

Mr Calvert said neighbours would not have to put up as much noise as they had in the first part of the project.

Work has also begun on a new bridge at busy Clark St-Rankin St roundabout, the first of four to be constructed over the trench, doubling the number of railway crossings between the New Lynn commercial centre and its rapidly developing hinterland.

But Mr Calvert acknowledged that continuing funding uncertainty over a station which the Auckland Regional Transport Authority and Waitakere City want to build for about $13.5 million may delay the opening of the trench as the last component of the western railway line duplication project between Newmarket and Swanson.

The authority is still negotiating for government subsidies from the Transport Agency.