Greater Wellington’s Harbourmaster says an ocean-going tug is a nice idea but there are doubts it would make financial sense.

Grant Nalder fronted the regional council’s Environment Committee this morning after the Interislander’s Kaitaki ferry declared a mayday last month with 864 people on board.

Concerns have been raised about the ability of Wellington’s tug boats to assist the ship, had they been required, because the tugs are designed for work in the harbour and not the open water.

All four engines on the Kaitaki shut down on Saturday, January 28, and the ship drifted a nautical mile (1.8km) towards Wellington’s south coast.

The Interislander ferry Kaitaki in Cook Strait, with Clifford Bay in the background, while sailing from Picton to Wellington. 26 February 2013. New Zealand Herald photograph by Mark MItchell

The ship’s anchors eventually managed to hold the ship steady while the leak in the engine’s cooling system was isolated and some power was restored.

The ferry slowly made its way back to shore escorted by several vessels, including two tug boats.

 “They are not ideal for the situation the other Saturday, however, even given those conditions, they were [there] and they were prepared to assist,” Nalder said.

“One of the senior masters on board the tugs was confident he could have got a line on the ship had the need arisen.”

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Regardless, it’s still unknown how successful that might have been, Nalder has said.

Nalder said the idea of an ocean-going tug was assessed some time ago and a proposal was made for a 65-metre tug permanently manned with 25 people.

“The ocean-going tug idea is a lovely idea but in budgetary terms, I don’t think it is one that would fly.

The vessel needed to have a day job to make it more viable, Nalder said.

“It needs to be a working vessel that pays its bills on a daily basis, but has the ability to provide better assistance than we can at the moment.”

Nalder said conversations were ongoing with CentrePort about looking at short terms options, like different equipment.

Early discussions were also under way with ferry companies about modifying their sailings, Nalder said.

The situation with the Kaitaki ferry was not a new risk, he said.

“It’s a known risk, but the scenario has finally played out.”

The Interislander’s Aratere ferry, Lady Elizabeth IV, two harbour tugs, a pilot boat, and a fishing boat were also called to the stricken Kaitaki.

“If abandoning the ship had become an option, then those boats have the ability to put lines on the lifeboats to assist them so they can be landed in a safer fashion,” Nalder said.

“Had they abandoned ship, people in life rafts is a very risky situation so there were a lot of people on standby watching and waiting to see what was going to happen next.”

The Transport Accident Investigation Commission has opened an inquiry into the breakdown. The Kaitaki started freight-only sailings last week.