Emirates Team New Zealand have suffered damage to the bow of their converted AC40 during testing on Auckland’s Hauraki Gulf in some top end conditions.
The resulting impact of the water pressure collapsed the foredeck at the bow of the AC40.
The team were testing under manual flight control to the north of Waiheke Island in around 15-20 knots of windspeed and large waves.
While sailing downwind at over 40 knots of boat speed, the crew onboard lost control of the ride height pulling the rudder and elevator out of the water.
This resulted in a high-speed uncontrolled gybe and simultaneous deep nosedive followed by a capsize.
The assigned Recon Unit reported that . . . Two good gybes were watched but the yacht was really starting to pull away, the chase/recon boat was doing 32-36 knots. Just before the capsize she had put over a mile on us.
Going into a gybe the rudder came out and the boat pitch-poled quite hard. She capsized onto her port side, the deck just aft of the chain plate has deflected and the whole bow section has come aft about 250mm and up about 350mm.
Damage was all forward of the watertight bulkhead.
Significantly the watertight bulkhead aft of where the damage occurred maintained its structural integrity, successfully serving the purpose of controlling water ingress so the boat could be righted and towed back to base.
No crew were injured in the incident and the AC40 was towed back to base on its foils after the incident and is back in the shed being assessed for the repair job ahead.
Emirates Team New Zealand CEO Grant Dalton described the incident . . .
“It appears that when the boat nose-dived, which was the best we have done, the high water pressure and side load collapsed the forward section of the deck causing the resulting bow damage.”
“The designers are analysing the load cases of the incident and although it might be too soon to tell, it is likely that we will have some retrofit structure necessary to our boat and throughout the AC40’s fleet. But we will understand this further in the coming days.”