The first of two $1.5 billion 27,000-tonne Landing Helicopter Docks (LHDs), to be known as HMAS Canberra, suffered excessive vibration in May during her first “shakedown cruise” between Melbourne and Sydney.
The fault was traced to the brand-new vessel’s two German-built Siemens propulsion pods — or azimuth thrusters — which were out of alignment.
Each thruster, fitted at the stern of the ship, has two propellers mounted on large electric powered pods that can be rotated to any angle, eliminating the need for a rudder. And just like the wheels of a car, poor pod alignment causes vibration.
A crew from Teekay Shipping Corporation was hired by prime contractor BAE Systems and was apparently unaware that the pods must be operated in tandem above eight knots.
They ran them independently in low-speed mode at high speed, causing serious vibration throughout the ship.
“Once the pods were back in the correct mode the vibration ceased,” a project source said.
“It was an operator error and the return journey was much smoother.”
The vibration was generated by cavitation and the bounce produced at the stern rolled across the ship with decks trembling and panels vibrating.
“It was like the shaking floor in an amusement park house of fun,” a source said.
Damage was minimal, but vibration caused paint to be stripped from the ship’s hull directly above the pods.
The crew’s woes continued when Canberra returned to Port Phillip Bay and was forced to drop anchor for four hours after losing steerage following an electrical power failure.
Unfortunately the operators forgot to disconnect the emergency power and when the main power kicked back in the circuit breakers melted.
“There were no major design errors during the trials and both issues were operator errors,” the source said.
“The trial didn’t go as well as hoped, but it was better than expected.”
In addition to the serious errors, excessive corrosion was detected in propeller nuts and a small crack was discovered in the hull of the ship that was caused during its long journey on a barge from the builder in Spain.
The Canberra will be back at sea in July for the next round of trials before she is handed to the Navy later this year.
News of the botched sea trials comes as the government announced it would insert an “experienced shipbuilding management team” into taxpayer-owned shipbuilder ASC in Adelaide to fix the troubled $8.5 billion Air Warfare Destroyer program.
Defence Minister David Johnston and Finance Minister Mathias Cormann said the team would target productivity and production schedules in a bid to get the controversial three-ship alliance project back on track.