Are you a little confused by all the different types of boats to be built and sailed in the 35th America’s Cup? Let’s see if we can sort them out.
The AC45F one design foiling wing sail catamarans raced for the first time in the Louis Vuitton America’s Cup World Series Portsmouth in late July. These boats will continue to race throughout 2015 and 2016 in the LVACWS events. A one design foiling package has been retrofitted to the original AC45 design, now called the AC45F. There are no other visible changes – the crew of five still sit on the hulls and the helmsman has a tiller. Wing camber and twist are controlled with lines on the foot of the wing. The non-foiling AC45 was already a very physical boat. With no grinding pedestals, the AC45F needs batteries to power the daggerboard rake control system, activated by pushbuttons at the helm and just behind the board cases. The horizontal stabilizers on the rudders can be adjusted between races with a worm screw at the head of the rudder, as on the AC72’s.
Now let’s look at the development boats. These boats will not race – they are platforms for testing design ideas and for training. In the turgid prose of the Protocol, these are charmingly called “a yacht allowed in Article 1.1(bbb)(ii).” Not surprisingly, the sailors have other names for them. Artemis Racing calls theirs Turbo. Oracle Team USA calls theirs Sport. Land Rover BAR uses T1 for test boat one. Before they withdrew, Luna Rossa just called theirs Piranha and Swordfish, the same names they had in their former life as one design AC45’s. The Protocol says that long as the lower part of the hulls is the same shape as a one design AC45, you can build whatever you want and modify it as much as you want. Land Rover BAR’s foiling T1 uses the standard hulls and crossbeams of an AC45 and looks just like an AC45F, although it surely has some systems in the hulls, out of sight. When last seen, Luna Rossa’s two test boats were also standard AC45 platforms, but with wheel steering and a cut out in the hull where the helmsman could stand.
Oracle and Artemis have shown the most interesting development boats. Both have flared hulls to make room for wheel steering and a grinding pedestal in each hull. Both have D-section crossbeams that are longer than the standard tubular beams, approximating the length to beam ratio of the now discarded AC62 rule. They also have centre pods under the wing like Oracle’s AC72. This was part of the class rule for the AC62 and is in the rule for the America’s Cup Class. The rudder locations are different on the OTUSA and Artemis boats, and Artemis has two winches per hull – one for the wing and one for the jib, while Oracle has only the wing trim winch. Oracle launched their boat in San Francisco with a full hydraulic control package for the wing while Artemis originally had only the line-controlled system, similar to the original AC45 wing controls. Artemis has since added hydraulic controls to their wing. These boats have electric pumps to provide enough hydraulic pressure for the board and wing controls, given that there is only one pedestal per hull.
While they were in San Francisco, both teams were already practicing manoeuvres and developing crew choreography. Both shipped their development boats to Bermuda and began sailing on the Great Sound in early May.
Now, what about the race boats for the America’s Cup? The AC62 Class was dropped at the end of March 2015 when the Challenger Committee voted to change the Protocol. Luna Rossa was on the losing side of that vote and promptly made good on their threat to withdraw. The 62ft long AC62 with a crew of 11 was replaced by a 48-50ft long, largely one design yacht with a crew of six. Colloquially referred to as the AC48, the new class confusingly has an old name: ‘America’s Cup Class’. The hulls, crossbeams and wing planform and section are all tightly specified in the class rule. The design teams have three main areas to be creative: daggerboard and rudder shapes, aerodynamic fairings and control systems for boards and for the wing. Protocol restrictions on launch dates mean we will see these boats for the first time in December 2016 or January 2017.
What will we see in the coming months? Presumably all teams will want to make their development boats as close to the rule for the race boats as they can. The Protocol allows them to build multiple wings for the development boats that are identical to the race boat wings. The limit of two wings for the race boat only comes in to effect when a wing is installed in the race boat. The daggerboards will be so close in size that the Protocol was changed to limit the number of boards that can be built for the development boats. Perhaps most importantly, will it be possible to build an exact race boat deck layout and control systems on top of the lower hull sections from an AC45? Given the importance of crew work in the tight confines and variable winds of Bermuda’s Great Sound, there are big advantages to be had from perfecting manoeuvres early, rather than waiting until you are facing multiple match points mid-way through the America’s Cup Match.
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