America’s Cup holders Team New Zealand are experiencing problems with their pioneering cathedral rigs, according to a report in Auckland’s New Zealand Herald on Friday.

While out two-boat training on Hauraki Gulf, a 25-knot squall caught TNZ by surprise and the complex carbon cathedral, or Millennium, rig on Bertrand Pacé’s NZL-57 snapped just above the second spreaders.

“It was not boat-threatening and, thankfully, no one was injured,” Dean Barker told the New Zealand Herald. “The real concern is that this is the second Millennium rig to break in the past month. There has to be questions now about the rig concept.”

The rig was used by TNZ in their cup defence and its success spawned several similar rigs, one of which crashed over the side of Peter Gilmour’s One World a few weeks ago.

“We are not sure what caused it,” said Barker. “It only needs one small failure in the rig for something like this to happen. There was no warning. Given good conditions, we hope to be back out tomorrow. We are lucky we have a spare mast.”

Prada, also two-boat testing at the time, offered assistance but Barker felt able to decline. “We were okay but were grateful for the offer. No one likes to see serious damage like this. It is not what we are about. It is part of the game but you do not wish it on anybody.”