Radical supermaxi CQS arrives in Auckland ready for sea trials

by Big Boat Racing on 17 Nov 2016 Ludde Ingvall’s revamped supermaxi, CQS, arrived in Auckland on Tuesday morning, after a tough and testing 125nm voyage from Tauranga. The trip was not without challenges including contending with strong headwinds and tsunami warnings.

Commenting on the passage Ludde said, “despite the concerns posed by the earthquake and tsunami warnings the trip was OK. We had 25 knots of wind on the nose nearly all the way, but we got there.”

The team now have a huge job list, with Hall Spars working on tuning the rig, in anticipation of the first sea trials over the weekend, weather permitting.

The rebuild of the yacht has transformed a formerly competitive 90 foot boat to a 100 foot high performance super maxi racing yacht.

The 90 footer was originally designed by South African naval architect Alex Simonis, but the new super maxi owes much to the design talents of New Zealander Brett Bakewell-White.

The new version is almost unrecognisable from the original boat, though about two thirds of the original hull is still there.

The technical innovations that have been incorporated push the limits of present yacht design.

In order to lengthen the hull a portion of the bow was removed and then very carefully calculated V-shaped cuts were made into the hull so that it is strung apart, a bit like opening the fingers on your hand. The V-shaped indents into the hull were then filled with gussets and a new longer bow created.

In order not to have to create a whole new foredeck, a chamfer was then fitted to connect the new bow section of hull to the old deck. This has the benefit of creating a smoother flow of air across the foredeck and onto the headsail.

The radical look of the new forward sections of the boat is further enhanced by a reverse bow and a long bowsprit.

The yacht has always been a relatively narrow boat and she remains so on the waterline. However, in order to support the much more powerful new rig the shroud base needed to be widened. In order to achieve this, a supporting structure has been put into the boat that is wider at deck level than the hull, so aerodynamic 'wings' have been created to contain the outer ends.

While wanting to retain the advantages of a narrow waterline all the way to the stern it became evident, through research conducted at the Yacht Research Institute at the University of Auckland, that for some of the new massive headsails that were planned, a wider sheeting angle would be critical. Hence the decision to run the maximum width all the way to the transom in the form of wing-like structures. An added benefit was also deemed to be the ability to maximize the use of crew weight for stability. Hence the motivation to create a wider platform at deck level.

All this has combined to produce a hull that looks radically different from any of the other super maxis.

Sailing boats rising out of the water on foils is not new. Sailors and designers have been experimenting with getting their craft to “break free”, or get “air time” for many decades. However, until very recently it was always small lightweight craft that were the test bed for these experiments and trials.

A keelboat does not lift its hull clear of the water like say a foiling moth, but the use of this technology can greatly increase the stability of a keelboat, and lift it a little, thereby reducing its displacement and wetted surface area, and therefore resistance.

CQS has an adaptation of this feature, a DSS aqua foil system, installed and she is one of the biggest boats currently using this type of technology.

The system uses a sliding board that runs across the boat from one side to the other, and protrudes from the hull just below the waterline. The board is deployed on the leeward, or downwind, side of the boat to give lift and added stability. The hull, in effect, becomes like an aeroplane with one wing.

When the wind works on a monohull yacht’s sails it has two effects, one is for the boat to lean over, and the other is for it to move forward. With the foil deployed on the leeward side of the boat, as it moves forward, the board starts to act like an aeroplane wing, and tries to lift. The faster the boat goes, the more lift it gets from the foil, thereby reducing the amount that the boat leans over, and therefore making the rig and the hull more efficient.

In the case of CQS, this technology is being combined with the already proven advantages of a canting keel. Brett Bakewell-White, who is the designer of the hull modifications said: “We think canting keel and aqua foil are complementary technologies; they enhance each other.”

With the aqua foil out one side and the canting keel out the other, the “aeroplane” now basically has two wings.

For a boat that is relatively narrow on the waterline, this double dose of righting moment is a material performance enhancer, and with the extra speed that this enhancement will deliver, the two wings will start to lift the boat, reducing the displacement and the wetted surface area. Result, more speed.

However, advantages like this don’t come without a cost. As Brett says, “If you increase righting moment you increase horsepower and you increase loads. You can add sail area and it doesn’t increase loads, the boat just tips over sooner. It’s righting moment that increases loads, not sail area.” There has consequently had to be a huge rethink on the engineering of the load bearing parts of the boat, hence the widening of the shroud base to give the mast more support.

All the boats that have so far tried a foil plank have been much smaller than CQS, and not fast enough to make it work consistently when going to windward. It is hoped that the extra speed generated by a boat of 100 feet, will enable her to lift while close-hauled. This will be a breakthrough in keelboat sailing.

For more on CQS click here