Wayne Mapp

Wellington, June 1 NZPA - The breakdown of the Navy's newest ship on its maiden voyage was a "teething problem" Defence Minister Wayne Mapp says.

The HMNZS Wellington had to divert to Sydney during its voyage from Melbourne to Auckland yesterday after a water seal leaked in its port engine and its starboard engine control system developed a fault.

Engine problems also struck Wellington's sister ship, the offshore patrol vessel HMNZS Otago, which had to delay its maiden voyage to Auckland in March.

Dr Mapp said he was confident that once repaired the ship would be a good naval vessel.

"No one expected this but I guess it's one thing to test the vessel outside the Port of Melbourne and another thing to cross the Tasman Sea in it. Remember this is its first significant voyage, this is where you are going to find the teething problems," he told Radio New Zealand.

"I am very confident when it's repaired it will be OK."

Dr Mapp was asked about problems with the ship being overweight which could potentially impact on trips to icy waters off Antarctica, as the ship sitting lower in the water would mean reinforced steel protection would not extend high enough up its sides.

"They're not as much as 100 tonnes overweight, it is more like half that," Dr Mapp said.

"We did get compensated for that as part of the compensatory package.

"What it does mean is the navy is now going to have to manage the increase in weight because there is always increases in weight of a ship over its lifetime, to ensure that it stays within the limits.

"Maybe towards the end of their life they may not be able to go to the Antarctic."

At present the vessels can visit the icy continent.

"But if the increase in weight over time, adding gear and all that sort of stuff, goes beyond a certain level then obviously that limits their operation and that's why the navy has to manage it.

"These are going to be excellent ships."

The Wellington was in the Tasman Sea about 650km from Sydney when the problem was discovered.

Technicians from the engine's manufacturer MAN met the ship in Sydney and were working with the ship's engineers. The engine is under warranty so repairs will not cost the navy.

The Wellington was now expected to arrive in New Zealand towards the end of next week.

It is the seventh and last ship in the $500 million Project Protector fleet, and with its delivery the navy will have a fleet of 12.

At its launch ceremony in Melbourne this month, navy chief Rear Admiral Tony Parr said Wellington and its sister ship were designed and built to patrol the exclusive economic zone, carry out surveillance and military operations around New Zealand, the Southern Ocean and the Pacific.

They could operate further offshore than existing navy patrol vessels, stay at sea longer, and conduct more challenging operations using their helicopter capability, sea-boats and embarked forces, he said.

Otago was carrying out sea trials off Melbourne to test her systems when the faults were found, the Defence Force said in March. The problem involved a manifold on one of the engines.