America's Cup - Aboard Emirates Team NZ for the End of the Beginning

by Richard Gladwell on 31 Mar 2017 Emirates Team New Zealand are well-advanced with the pack-out process on their America's Cup Challenger after wrapping up their New Zealand testing program with some media being invited along for what proved to be the final sail on Tuesday.

In the six weeks that has elapsed since the AC50 was launched in Auckland, the team has worked through their testing checklist. 'It feels about the right time to be leaving', says team CEO, Grant Dalton.

In that six week period, the AC50 has retained the very simple, clean looking cockpits along with the four cycling pedalstals that were unveiled on February 16, to a layout around the helmsman and wingsail trimmer that has more in common with a Playstation console.

Banks of buttons lie within reach of the helmsman and wingsail trimmer. No labels - just a multitude of colours. The steering wheel is also emblazoned with adjustment buttons and to the right of the wheel is docked a very clear portable computer screen.

This is a boat with just two sheets and no winches - just hydraulics. She looks a surreal sailing craft, with the nearest concession to rope being the wingsail and jib sheets - which are grey coloured Dyneema lines attached to hydraulic adjustments and are untouched by a trimmer’s gloved hand.

Today's test session begins with the AC50 and two chase boats exiting the Westhaven channel entrance into a building easterly breeze. Just clear of the marina entrance the wingsailed catamaran climbs effortlessly onto her foils, as the cycling team packs down and gets into their work.

Today the AC50 is fitted with unmatched daggerboards and handles differently on each tack and while tacking and gybing.

Visually there is no difference between the two boards from the chase boat. But the difference is apparent tacking in lighter air when the AC50 sinks during a tack one foil but stays flying on the other tack with the higher lift foil.

Later, in the afternoon session, Dalton explains critical role played by the team meteorologist in the foil selection. A call has to be made the night before as to the likely weather for the following race day. The foils then have to be in place and ready for measurement by 0900hrs on race day, and then the shore team have a further two hours of adjustment with foils and tips to get them aligned and matched perfectly.

'Get that weather call wrong, and we are in big trouble on race day,' says Dalton.

The difference is obvious even in the first couple of miles in a 6-8kt breeze in the morning session - close to the minimum allowed for racing in the America's Cup. The distance lost in a muffed foiling tack or gybe can be as much as 300metres - a race defining margin - and all hanging on a correct weather call.

One of the key points of interest in Bermuda will be the daggerboard strategies followed by the different teams

As we continue to head out to the practice session, the AC50 turns on a dime as helmsman Peter Burling plays nip and tuck with the harbour shoreline.

Crossing the platform
Up close we can see what happens as the crew cross the boat during tacks. It is not quite leisurely, but the cycle power definitely seems to give an edge as power is maintained by two grinders, while the other two cross and take up the task on the new tack.

Helmsman Peter Burling crosses - the wheel looks unattended while he does so, but out of sight, wingsail trimmer Glenn Ashby reaches behind to hold the wheel and keep the boat on course before he too makes the transition to the new windward side.

With the wind expected to build further, the AC50 swings into the first routine of the day - an ongoing figure of eight series of manoeuvres between some laid marks.

The exercise has its roots in the Olympic classes, and its purpose is to refine the crew manoeuvres through a continuous series of tacks and gybes.

'It's a good test of the systems - if your crewing systems break down you never catch up,' says Dalton observing the relentless pneumonic cycle which passes without an apparent glitch for about 20 minutes.

Next up is a planned match racing session, but the wind softens, and we head back towards the City looking for the elusive breeze.

The drill with match racing - despite having only a single AC50 is to use one of the two Yamaha powered Protector chase boats as a competitor to put the AC50 crew through its manoeuvres.

While a little unusual, the approach does have the benefit of the chase boat being more accurate with its placement. With top match racing skipper and coach, Rod Davis on a chase boat and hooked up by radio into the skipper and crew of the AC50 the practice session is expected to be sharply interactive.

But it is not be.

The breeze drops further, and the AC50 is back to base for a part change before heading back out onto the water for another testing session in the elusive breeze.

AC72 or AC50?
Four years ago it was a different story, heading out on a media day with Emirates Team New Zealand's AC72. The conditions couldn't have been more different with 20-25kt winds and the 72ft wingsailed catamaran, skippered by Dean Barker hitting 45kts.

The two wingsailed foiling catamarans are similar but different. The AC72 Class Rule was not written with foiling catamarans in mind, and foiling was developed by the New Zealand team sending shockwaves through the sailing world, with most believing initially that it was a photo-shopped hoax.

While the top speeds of the AC72 and the AC50 are the same - top ending at around 50kts, it is in the lower to mid-range that there are big differences.

The lumbering power of the AC72 was very impressive, along with the noise and magnificence of a very special sailing structure moving at high speed.

The AC50 is like a fighter plane in comparison - designed to foil. The AC50 is quickly airborne and settled into regular flight mode which is three times wind speed - way faster in the light and mid-range than the AC72.

The AC50 also foils upwind, which the AC72 could only be coaxed to achieve in the top end breeze in San Francisco. Foiling is achieved in just 6kts of air at speeds of 12-15kts.

Media days are about the only chance for those outside the Team to see the wingsails up close and how they are tweaked through the wind range.

Constructed in a similar fashion to a model aircraft wing, with a plastic film stretched over a carbon framework. The theory is the same as the wings on a bird or a plane rather than a sail. And like all man-made wings, they are just Man's attempt to crudely replicate what Nature has refined.

Essentially wingsails consist of a front element or spar/mast like a conventional yacht which is secured to the hulls with stays. It rotates to provide the shape in the wingsail.

To see the amount of rotation in the front element, you look at the top of the spar and see the angle the end plate has been turned. The bottom of the wingsail is hardly moved off the centreline. It is all about twisted shape.

Attached to the front element are the three trailing flaps or elements which are independently adjustable by the wingsail trimmer. What we are looking at today, up the back edge of the wing is the degree of the trailing edge of the wing (leech on a sail) being closed - to give maximum power, or twisted open to get the AC50 sailing at its most efficient.

The fascinating aspect of both the AC72 and AC50 wingsails is the amount of twist that can be induced by the wingsail trimmer - with the sail looking like a single aerofoil - despite being several separately adjusted components.

The wingsail is an impressive piece of engineering, and of course, all driven by cables and hydraulics. It is much more refined than an aircraft wing, and the finely twisted shape is akin to the wing of a soaring albatross. You could watch it for hours.

There is none of the frantic adjustment, grunting and grinding that you see on a racing yacht. On the AC50 it all happens imperceptibly, with no noise. The wingsail almost looks alive as it changes and rotates and the AC50 below it responds.



Light airs a cat-killer
Given the amount of work that has gone into developing the sailing technology used in the AC50, the hope is that there won't be racing in very marginal conditions that were seen at times in the America's Cup World Series.

The search for wind on the Waitemata proves to be fruitless but provides some interesting interludes including the sight of the whole six crew positioned in the leeward hull, as the windward one flies high, and later repeated with just helmsman Peter Burling high in the windward hull as the AC50 trundles along in rare displacement sailing conditions.

Talk on the boat turns to the recent series of practice races held between the five teams in Bermuda.

Some of the racing was conducted in very light conditions with what appeared to be streaky wind - a bit like what the team is seeing on the Waitemata now. The fact that there were some big gains and losses on the races sailed in the light underlines that for all the technology, development and refinement a lot of luck comes into it and an AC50 getting a sniff of a breeze and foiling will make a huge difference to a race outcome.

We're seeing this right now in the funky breeze as the AC50 lifts out and then drops back into displacement mode. Not a lot is said, but everyone is thinking the same thing - 'hope we don't get this weather in the Cup'.

The wind gives up eventually, and the AC50 is hooked up for a short tow back to the marina, before being strapped alongside for the docking.

Then the haulout process begins for the final time in New Zealand, with the AC50 expected to fly out of New Zealand in the first two weeks in April.

Next time New Zealand’s ninth America’s Cup Challenger, Aotearoa New Zealand sails on foils again will be above the Great Sound in Bermuda