America's Cup: Emirates Team New Zealand continue testing
by Richard Gladwell/Sail-World NZ 10 Sep 2019 19:51 PDT
11 September 2019
Emirates Team New Zealand - Luna Rossa spy boat in close attendance - Auckland, September 11 , 2019 © Richard Gladwell
America's Cup Defender, Emirates Team New Zealand continued their "softly, softly" work up of their first AC75 on the Waitemata Harbour, off the team's base, on Wednesday morning.
Following towing tests of the foiling systems earlier in the week, a weather window of light wind allowed the mainsail and jib to be hoisted separately with the team chase boat alongside. It is believed to be the first time that the team has hoisted the double skin mainsail.
A crew member was high in the rig for much of the session, working on what may have been halyard/hoisting issues.
Emirates Team New Zealand are the only "super team" who did not launch a prototype boat and were expected to have a longer lead-in process for systems on their first launched AC75.
The team launched around 7.30am to take advantage of light winds before the breeze began to freshen around 11.00am when the team headed for their base in the the America's Cup Village.
In close attendance was at least one spy boat, said to be from Challenger of Record, Luna Rossa Prada Pirelli. While there are rules governing Reconnaissance in the Protocol, the taking of photos and video from a boat are not listed amongst the prohibited actions. However rival teams are not permitted to interfere with another competitor's yacht when it is sailing or being towed.
The mainsail hoist revealed that the AC75 is likely to have a "deck-sweeper" foot on her mainsail, which will form an end-plate effect on the unusual centre pod that dominates the cockpit of "Te Aihe". A smaller dimension strut, and battening, is expected to take the place of the traditional main boom and the sail is expected to be sheeted more like a jib. Emirates Team New Zealand skipper Glenn Ashby used a variation on the "boomless" mainsail to win his last A-class catamaran world championship in Queensland.
The concept is not new, and was first used on genoa jibs in the Flying Dutchman class in the 1960's with round in the genoa jib foot used to form a seal between the sail and the deck.
Under the AC75 class rule the upper and lower sections of the mainsail are largely unrestricted in terms of batten size and placement, allowing design innovation to replace the heavy mainboom, along with its attendant sheet loads. The middle section of the double skinned mainsail only six full length and six leech/flutter battens are permitted with a maximum length of 1000mm. All battens are carbon, except inflatable battens could be used in the upper and lower mainsail sections if desired.
A similar weather pattern, of lighter breezes in the early morning freshening late morning is expected to continue for the rest of this week - conditions which ETNZ were seeking as they continued a process of system testing and then sailing. The forecast for next week is more conducive to full sailing days.