Hi all, the Christmas races were abandoned due to lack of wind. If you want to see all the things that might happen then try You Tube, AC 75, Day 3 race 12. Looks bad for one but just keep watching.
The design of the hull comes to the fore as to what happens on a touch and also for the time it takes to get back onto the foil and cock ups on timing the foil change over.
The GB boat looks as good as done for! We have used our ration of 6 foils and so the existing ones have to be re-examined.
The designers are allowed free rein on the foil design and this includes the adjustable trim tabs but this is not allowed to be automated and the boat data is actually delayed when being read from the boat. This done through a 'media box'.
The cant arms were designed in New Zealand and are operated by hydraulics. There is an electric motor driving the hydraulics but this is not powerful enough to operate the cant arm. These are operated from an accumulator (oil) which is pressurised by the 'Grinders'. They take 15 seconds of hard labour each time an arm is moved. A cant arm takes 3 seconds to travel an arc of 50 degrees.
So amongst the non Grinders there is an arm operator and a 'flyer' who controls the 'flight' of the yacht through the water. There is a fixed foil at the base of the rudder.
The next races are in January when GB, Italy and USA compete with each other in the Prada Cup. The winner will compete with New Zealand for the Americas Cup on the 6th. March. Italy and the USA look very well matched and it might come down to local knowledge with the Captain of the Italian boat Jimmy Spithill who was in the Oz team last time.
Some facts, boats cost 8-10$M (US). The arms are supplied by the development company in NZ and are all the same, they weigh 1.4 tonnes each. The yachts weigh around 8 tons and it is the leeward foil which is in the water, but the yachts use both foils in the water to get up to speed.
The hulls sail slightly bow down and about a 300mm or slightly more when travelling at speed.
The wind may only be 10 knots but the yachts can achieve 35/40 knots speed.
The main sail is 2 sails that come together at the back of the sail, this forms an aerofoil section. The sail travel is about 20 degrees either side.
There is a heavy dependency on the software.
Holland Malta and France withdrew leaving just 4 boats in all.