INEOS Britannia’s Hot New AC75 Ready to Launch

INEOS Britannia's AC75 is out in the open, adding to the intrigue in this month of new-boat launches ahead of the 37th America's Cup.
INEOS Britannia’s new-generation AC75 undergoes systems commissioning on April 20. AC Recon

Alinghi Red Bull Racing, Emirates Team New Zealand, Luna Rossa Prada Pirelli, and now INEOS Britannia, have revealed their AC75 weaponry for the coming 37th America’s Cup, leaving the French of Orient Express Racing Team and American Magic to show their wares in due time. But all eyes this past weekend were on the British base in Barcelona as the team broke dawn with an unceremonious rollout of what is referred to by the team as “RB3.” And, like the other AC75s that have emerged over the past few weeks, this latest flying yacht is a marvel of shape and aerodynamic slickness that only time will tell whether its right or wrong enough to win the Cup.

INEOS Britannia, the British Challenger of Record representing Royal Yacht Squadron Ltd, had kept its AC75 development under tight wraps for its two-year build in England, but in the process of stepping the rig and commissioning the AC75 this weekend, the boat had to be exposed, and under darkness, the team rolled it out of the shed to delight of team members and AC recon personnel on hand to take notes and report.

An aft view of the British team’s AC75s shows the deep “tunnel” between offside crew pods. AC Recon

“The plumb bow starts sharp and maintains a steep deadrise toward the forward cradle, flaring out to a flat bottom from foil arm pivots,” the Recon observer reported. “A noticeable bustle starts off in a bulbous form, about 1m from the bow, continuing to the transom, tapering off towards the stern. A thin skeg runs horizontal down the bustle, enlarging as the hull bottom rises to meet the deck, ending a few meters before the rudder housing.”

The bustle, or skeg, is certainly a common feature for all current AC75s, and while each team has taken a different approach, that of RB3 is most radically different in its termination at the stern, but there’s much more to interpret from the Recon team’s observations: “The sheer line raises from the bow and the flat deck continues to the sidepods. The sidepods start behind the [one-design] foil-cant arms, containing four crew pods in line on each side, separated with a trench deck approximately one foot deep. The trench runs flat down the middle to the transom, with a gentle flare to meet the sidepods.”

RB3’s mast gets stepped for measurement and calibration, revealing Harken’s hydraulic cunningham systems. AC Recon

Whereas most other teams have revealed with older foil configurations, the British shrouded what are believed to be a new set, but noteworthy is the location of the bulb forward of the wings. “The leading edge of the foil recedes slightly from the one design section, and continues to the front of the torpedo bulb,” Recon reported. “The high aspect wings connect aft of the bulb, slightly anhedral, with pronounced wingtips. The starboard wingtips had boxes over them, perhaps with camera bulbs on them as on ARBR [Alinghi Red Bull Racing] Boat One. Toward the end of the day, the shrouding fell slightly, revealing seemingly unfinished paint work.”

AC Recon

According to a team statement following the rollout, INEOS Britannia Team Principal and Skipper Sir Ben Ainslie said: “This is a big day for the team…Thousands of hours of work have gone into this boat and so it’s great to finally reveal her to the world. Things are really stepping up in the campaign now, and we are looking forward to launching RB3 and getting out on the water very soon.”

Once launched, the British team will join Alinghi and Luna Rossa on the waters of Barcelona as the regatta nears its beginning in August with the Louis Vuitton Challenger Series, which continues through