Cracks found in frigate's hull

By GREG ANSLEY and KATHERINE HOBY

Cracks have been found on the hull of the Navy's first $A560 million ($677 million) Anzac frigate, Te Kaha, following a warning from Australia of similar faults in its Melbourne-built warships.

Work is already under way in Auckland to repair Te Kaha, and checks will be made on its sister-ship Te Mana when it docks for routine maintenance in August.

Te Mana is on exercises in Southeast Asia with the fleet oiler Endeavour.

Te Kaha was launched in 1995 and commissioned two years later, and Te Mana entered service in 1999.

Te Kaha's latest problem follows the replacement of a faulty gas turbine engine in 1998 and repairs to propeller driveshafts the following year - both carried out under warranty - and the loss of a capstan ripped from the deck by a 17m wave in Antarctic seas in 1999.

Australia has started checks and repairs on the three Anzac frigates in service, and plans to modify the five ships yet to be commissioned before they are handed over to the Navy.

Chief of Naval Staff Rear Admiral Peter McHaffie said he was "naturally disappointed" at the discovery, but said both frigates remained safe for sea and normal operations.

Te Kaha and Te Mana are understood to be out of builder Tenix Corporation's warranty period, although Tenix spokesman Liam Bathgate said discussions on responsibility for the cost of repairs were being held with the joint office administering the Anzac ship project for both navies.

The faults are described as surface cracks along the bilge keels where they join the hull.

The two fin-like keels run beside the main keel, and are designed to increase speed and stability of the ship and reduce rolling in heavy seas.

An Australian Navy spokesman said yesterday that the cracks, probably caused by flexing of the hull, had first been noticed on HMAS Arunta - the third of the class, after HMAS Anzac and Te Kaha - during routine maintenance.

Similar surface cracking was later confirmed on other Australian frigates.

After discussions with designers Blohm and Voss, Tenix engineers designed modifications involving the removal of the bilge keels, strengthening affected areas to prevent further cracking, and refixing the keels.

The work, being carried out on Te Kaha at the Navy's Devonport dry dock, takes about two weeks and will be included as part of routine maintenance.

Repairs have already been carried out on Arunta in Australia and are under way on HMAS Warramunga.

Tenix said the cracks had no impact on the performance or operational capability of the ships, a position supported by spokesmen for both navies.

However, the top brass in the Royal Australian Navy felt concerned enough about cracks in the welds in their own ships to warn their New Zealand counterparts to check their frigates.

The cracks in the hull - the longest is 100mm - are "not a big issue", says Captain Bruce Pepperell, in charge of ship support.

Te Kaha was due to be dry-docked for its annual maintenance period at this time anyway. Repairs would be undertaken during the maintenance period.

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