Update
US Olympian Caleb Paine at work during the 2018 Finn Europeans in Cadiz where Ed Wright returned after his break, slotting back in at the top as if he’d never been away. Wright now looks the main challenge to Giles Scott in the Men’s Heavyweight Singlehander; on which note, if there was ever a sailing class that perfectly encapsulated what the Olympic Games is meant to be about then surely it is the Finn. Incredible then to hear (incredibly stupid – ed) that this is the class most under threat of deselection for Paris 2024. If the powers that be do want Olympic sailing to become the ‘Olympic lightweight watersport event’ they should come right out and say it
THE LADY DOTH PROTEST TOO MUCH – Jack Griffin By the time you read this the AC75 Class Rule will be published. We’ll have answers to the big questions of the rig and the one-design elements of the foil-control systems. We’ll also know more about what amount of instrumentation and control will be allowed. And we’ll have a better idea of how realistic Article 11 of the Protocol is – that’s the part about cost containment. Emirates Team New Zealand are in their comfort zone – foiling
boats and heavy reliance on their simulation technologies. Adolfo Carrau of Botín Partners, who are leading the design team of the New York YC challenge, says that their calculations confirm that the AC75 should foil upwind and down in 9kt of true wind speed. Presumably that means in a straight line. Carrau cautions that the racing format will dictate both design
and sailing technique. The announced plans for upwind starts have people talking about dial-ups and pre-start circling. We are many months from knowing whether that is realistic. Perhaps keeping well away from your opponent and executing a perfectly timed foiling Vanderbilt start will be the holy grail of this Cup. Or perhaps the holy grail will be going through the pre-start without capsizing. Carrau also states that the concept and physics of the boat are
not the most difficult part. The mechanical engineering of all the systems will be the biggest challenge. The structural engineering of multihulls is fairly well understood. But the load cases and worst- case scenarios for the AC75 first need to be imagined before they can be solved. Even assuming that the foil-lifting systems are one-design or supplied equipment, the systems for the control surfaces on the foils will give the mechanical and structural engineers plenty of work.
10 SEAHORSE As with the AC50s, the user interface to the flight-control system
will offer opportunities for creative solutions. The video game controllers that Glenn Ashby and Blair Tuke had on ETNZ’s AC50 give us some hints of ideas the teams will explore. Less visible but nearly as important on their AC50 were the multiple locations of the foil controls. Since both boards could be raised, dropped and raked from either hull, the team could develop the no-look tacks and gybes that gave them an important tactical edge. By publication of this issue we will also know what the AC75 Rule
says about ‘measurement condition’. Or, more interestingly, if the rule attempts to limit fully automated flight-control systems used during testing and then stripped out once the sailors have learnt how to sail the boat the same way the computer does. This kind of system was used most successfully by ETNZ as they
developed their AC50. This Cup may well be decided by how well a team design their automated flight-control system and how well they transfer what it teaches them to the rule-compliant systems their sailors will race with. This looks like another opportunity for unrestrained spending. ETNZ have assured us that the foil geometry and ballast will
make the AC75 self-righting in case of a capsize. While that is comforting, it also implies that a lot of components will need to be hardened to withstand dunking in saltwater. Reliability engineering on a 75ft boat takes on additional meaning when capsizing is to be expected. Beefing up these systems will add significant expense. The rig for the AC75 will have a huge impact on how the boats
are sailed and raced. The wingsails on the AC72s and AC50s were a logistical headache but they were massively powerful and efficient. Will the sailors be able to trim the soft mainsails on the AC75s to enable foiling tacks and gybes? It would be interesting to know what
ROBERT DEAVES
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