Loose screw led to abandonment
X-yachts has released findings into an investigation into why Brainstorm, an X49, had steering failure and began taking on water before being abandoned in the ARC January.
The report concludes that a loose grub screw led to the rudder stock coming out of the top bearing, with a subsequent loss of steering. The movement of the loose stock then damaged a GRP tube which encapsulates the bottom bearing and forms a water seal towards the inside of the boat, which caused the yacht to take on water.
The crew of Brainstorm contacted X-yachts by satellite phone and were able to steady the water ingress to a level that the bilge pumps could keep up with. However, they were only partly able to secure the top of the rudder stock and, with conditions anticipated to worsen, the decision was made to abandon. Fellow ARC participants What’s Next and Rhapsodie VI diverted to assist.
Chris Line, skipper of What’s Next, a Jeanneau Yachts 54, described the rescue on the rally blog: “We arrived on station close to midnight and four very ingenious Dutch crew had managed to stem the flow of water for the time being, although [it] could fail completely at any time. After considering all options it was agreed that it would be safer for everyone to effect a rescue and transfer of crew at first light.
“Although the sea state was light to moderate the swells were still up to 2m and it was pitch black. We killed our engine and kept a mile down wind of them standing by in case the situation worsened. In these conditions the boats are not comfortable places to be!
"The rolling and banging as waves hit you on the beam is exhausting, especially for Brainstorm’s crew who were still trying to keep their boat afloat as long as they could.
“The following 12 hours was definitely a time where you realised how fragile life is. Although the communications continued with search and rescue, ARC control and other vessels, very little was said on What's Next. Everyone knew what to do and we all hoped that luck would hold out at least until daylight.
“I am pleased to report that early afternoon Brainstorm’s crew were successfully transferred to the relative safety of What’s Next and
Rhapsodie, who arrived to assist at midday."
Four days later, a salvage firm found Brainstorm using its YB Tracker. The salvage crew was able to reposition the rudder stock and secure the top rudder bearing, repair the leak and pump out the yacht. Brainstorm was then towed to Gran Canaria, approx 1,400 miles east.
X-yachts’ director of design & engineering, Thomas Mielec, met Brainstorm on arrival to identify the cause of the damage.
He explains: "It appeared that the top bearing had separated, and the rudder stock had dropped down. The rudder bearing union nut, which holds the bearing together, had simply turned off the thread at the bottom of the inner housing, and this meant that the rudder and rudder stock, which are otherwise fixed in the bearing, had dropped downwards and out of the bearing.”
”This happened even though the locking screw was in place [...] The other parts of the bearing showed no signs of overload prior to the incident."
The report suggests that either, in error, the locking screw was never secured with Loctite during manufacture of the bearing, and that the screw had loosened unnoticed over a period of two years also allowing the nut to unscrew, or alternatively the screw may have been removed/ loosened by mistake during service work carried before the ARC in November. X-yachts is checking for traces of Loctite.