Photo / Steven McNicholl

Photo / Steven McNicholl

Auckland's long-awaited $1 billion rail electrification project is back on track, under Government funding approval to buy a fleet of zippy and low-polluting new trains.

After keeping rail passengers in suspense for eight months, Transport Minister Steven Joyce yesterday announced the Cabinet had approved $500 million for electric rolling stock to start running in 2013.

That is on top of a commitment of $500 million the Government inherited from Labour to electrify Auckland's railway tracks out to Papakura and Swanson, and will include the purchase of up to 114 electric multiple unit (EMU) railcars.

These will be able to accelerate and brake faster than the diesel units they will replace, potentially allowing 10-minute service frequencies and costing less to run.

But the Auckland Regional Transport Authority may still have to lease up to 13 electric locomotives to pull existing refurbished British SA carriages along the southern line.

Although the authority originally sought 140 railcars, Mr Joyce said the proposed units would be longer and the overall fleet capable of carrying an equivalent number of passengers.

They are expected to be more cost-effective and efficient, although numbers and dimensions remain to be finalised.

"The consensus of all the boffins is that they will do the job," Mr Joyce said.

"I think it's good for Auckland and underlines the commitment we have made to not just roading budgets but to the trains - my view has always been that we have to use all the corridors we have got effectively if we are going to keep Auckland moving."

A multi-agency working party of officials alarmed regional leaders in August by proposing just 75 electric railcars, which although measuring 24m instead of 20m envisaged for a larger fleet, would have reduced capacity.

That followed their identification of $151 million of potential extra spending elsewhere in the electrification project and the region's $600 million basic rail upgrade.

But Mr Joyce rejected their recommendation and ordered them to maximise the number of railcars obtainable within a $500 million funding cap.

He said yesterday the overhang had been reduced to $45 million of essential spending, much of it for lengthening station platforms, and he wanted officials to meet it from Auckland's three main rail capital budgets totalling $1.6 billion.