Train specs mindful of tunnel plans

Auckland's new electric trains must be capable of running through future tunnels beneath Waitemata Harbour, KiwiRail is telling international suppliers. Photo / Mark Mitchell

Auckland's new electric trains must be capable of running through future tunnels beneath Waitemata Harbour, KiwiRail is telling international suppliers.

In a document seeking expressions of interest in supplying a fleet of 38 electric multiple units (EMU) by 2014, the Government-owned rail company says they must be designed to allow operations through tunnels under both central Auckland and the harbour.

These would involve "significant underground running" and operations through underground stations, it says.

In the case of the proposed 3km inner-city tunnel between Britomart and Mt Eden, the trains would have to run up a steep 1-in-26 grade, including curves with a radius as tight as 100m.

Although a study team commissioned by the former Transit NZ and Auckland councils favour road and rail tunnels for the next harbour crossing, Transport Minister Steven Joyce is not ruling out a new bridge for a project he hopes will be ready by 2025.

The number of railcars making up each EMU is not stipulated, but the KiwiRail document says they will be about 70m long, meaning a likelihood of three-car trains capable of seating 240 passengers.

They will be built of stainless steel and have a maximum speed of 110km/h, with better acceleration and braking power than Auckland's existing diesel fleet.

The document is the second in preparation for a supply and maintenance contract to be signed early next year, and will be used to compile a short-list of contenders by July.

Although KiwiRail has decided against bidding for its own contract, and building the trains in New Zealand as sought by the Rail and Maritime Transport Union, that organisation is welcoming what it calls "strong local content provisions".

Overseas firms are encouraged to ally themselves with New Zealand contractors or suppliers for the purpose of responding to the document, which says local content could provide them with an option to secure a local base from which to provide a cost-efficient maintenance service.

But no requirement for local content is included in a list of "non-price" attributes on which contenders will be scored for KiwiRail's shortlist.