Replacement Cook Strait ferry breaks down

The Stena Alegra, the replacement Interislander ferry for the crippled Aratere, returns to port after breaking down. Photo / SNPA/Ross Setford

A replacement ferry brought in to provide cover for Interislander's out-of-service Aratere is stuck at Wellington's Aotea Quay after losing power - less than a week into service.

The Stena Alegra, which began sailings across Cook Strait on Monday, had been ordered from Europe for the busy summer period after the Aratere lost a propeller on an interisland trip in November.

However, a problem with power on the ferry, which has affected the control systems of one of its propellers, has forced it to be sidelined for much of today.

Kiwi Rail said the ship suffered a partial loss of power when it was leaving Wellington about 5am for a freight-only trip this morning.

Technicians were looking into the problem and the ship had berthed at Aotea Quay while the issue was investigated, Kiwi Rail said.

Scores of passengers booked on the 9.05am passenger vehicle sailing from Picton had to be re-booked with the breakdown forcing the cancellation of that service, Kiwi Rail said.

Nearly 150 passenger vehicles had been booked for the sailing.

"We expect to be able to provide an update on this ship's status and this evening's 5pm sailing from Wellington later this afternoon," Kiwi Rail said.

"Our staff are working hard to find a solution to the fault and get the ship back into operation. We apologise to our customers for the disruption and will issue an update as we have more news," Interislander general manager Thomas Davis said.

The Aratere appears out of the fog. Photo / File / Mark Mitchell

Meanwhile, the Kiwi Rail website has suspended bookings for sailings from Picton to Wellington for today and tomorrow.

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