While no other Cup team has yet capsized with its new AC50 catamaran, this happened for the second time yesterday to the defending champion Oracle Team USA. During training, in which pre-start manoeuvres were to be practised, a gybe with subsequent fast luffing apparently failed and the boat lay on its side. However, the cat was righted and towed back to base in just three minutes. According to a statement from the team, nobody was injured and there was only minor damage, and they plan to continue training today.
The capsize in the video
It is not clear whether the capsize had anything to do with new manoeuvring procedures. Two days ago, a new installation was discovered on the defender, a bicycle behind the helmsman. This means that the New Zealanders are no longer the only ones to rely on wheel drive. However, this change at Oracle Team USA probably has a different background to that of the New Zealanders.
And from a different perspective
Emirates Team New Zealand has four bicycles in the cockpit on which the crew provides the hydraulic power needed to operate almost all the systems. More energy can be generated with leg power than with the arm grinders used by all the other teams. Team New Zealnd has already demonstrated very agile manoeuvres and very good speed in this constellation during training.
The video of the team, with onboard recordings
However, the higher energy supply is only one reason why the New Zealanders rely on bicycles. With them, the helmsman and foil trimmer functions are shared, at least some of the time. While in all other teams the helmsman simultaneously adjusts the direction of the cat as well as the flying position via foil adjustment using different control systems on the bike, in the New Zealanders' team helmsman Peter Burling is primarily responsible for steering. His former 49er foresailor Blair Tuke, who sits on the front wheel, directly above the foil, is responsible for adjusting the foil over long distances. As he needs free hands for this, which he would not have on a grinder, this was another reason for the New Zealanders to put the crew on wheels. However, this division of tasks requires extremely good coordination between the two active players, which is only possible with Burling/Tuke due to their 49er years together.
At Oracle Team USA, helmsman Jimmy Spithill is responsible for both course and attitude. The new bike behind his helmsman position is apparently primarily used for weight trim on downwind stretches. There it is important to have the weight aft. This trim can also be achieved by adjusting the T-foils on the rudder, but this creates more resistance on the foil. Tactician Tom Slingsby is on the wheel, but on upwind courses he will be in fourth position from the front on the grinder as usual, because on this course it is better to have the crew weight a little further forward.
The fact that Slingsby sits aft on a wheel probably has less to do with the increased power he can generate by pedalling and more to do with the limited space available there. A grinder would take up more space than a wheel.
Oracle Team USA does not appear to be copying the New Zealanders' pedal drive, but simply testing a new trim variant. However, this apparently has nothing to do with the capsize, as the videos show that no crew member was behind the helmsman during the manoeuvre.
In a large technical report, the functionality of the new AC50 catamarans is explained in detail, with unique and exclusive insights into the rudder and foil adjustment. This report, as well as everything else you need to know about the upcoming America's Cup, can be found in a 32-page Cup special in YACHT 12/2017, available on newsstands from 24 May, two days before the start of the Round Robins.
Lars Bolle
Chief Editor Digital
