27 March 2017

Shockwave

A great photo surfaced recently on the Farr Yacht Design Facebook page of Shockwave, the champion Two Tonner from 1992.  The photo looks like it was taken during the 1992 Kenwood Cup in Hawaii. More on Shockwave from an earlier article can be seen here.



26 March 2017

Kialoa IV (Holland Maxi)

This post is a tribute to the late Jim Kilroy (1922-2016), who campaigned, with great distinction, a series of yachts named Kialoa from 1957 to 1989. This article features Kialoa IV, the replacement for his famous Sparkman & Stephens-designed ketch Kialoa III.

Kialoa IV was the first of a new breed of maxi-raters, just over 80ft long, and was designed by Ron Holland in 1979 and built using a composite sandwich-laminated hull and deck with aluminium reinforcing. The latter being in the shape of a space-frame chassis incorporated into the hull to take keel and rig loads. Kialoa IV was built by Holland's brother-in-law Gary Carlin at his Kiwi Yachts yard in Florida, which had also built the famous Imp which pioneered the space-frame concept. The composite laminate was influenced by studies carried out by both Kiwi Yachts and Dupont's research department in Wilmington. Holland noted at the time that "While all-up hull weight advantages were not a primary consideration, the tests showed lighter ends and deck were possible compared to Kialoa III".
Kialoa IV in early days, possibly during the 1981 SORC
Holland described the design philosophy at the time as incorporating aspects from his successful level rating and Admiral's Cup designs that had not yet been utilised at the Maxi scale. "Hull shape is as influenced by the IOR measurement procedure as my smaller designs. Keel and rudder designs are treated in a similar way. Choice of rated length, displacement and sail are the primary starting point for my IOR designs, attempted to hold proven relationships although there are aspects of the IOR rule that dis-proportionately penalises the larger yachts due to necessary low displacement length ratios and associated sail areas. Scaling effect needs to be handled carefully but decisions on this, and the earlier mentioned points relating to Kialoa's first series success speak for themselves".
Kialoa IV during the 1981 SORC (photo Seahorse)

Kialoa IV was launched in November 1980 and Kilroy immediately began a working-up programme for the new boat which involved her trialing against her predecessor, Kialoa III, which would later be converted for cruising. This was a unique opportunity, where use a pace boat had previously proven effective with Admiral's Cup size yachts (such as Big Apple and Marionette in 1977), but this was the first time that this had been done with ocean racing yachts at this scale.
Kialoa IV powers upwind - 1981 (photo Hood sails)
Initial testing showed the new yacht had an advantage in light and medium conditions in the smooth waters of Tampa Bay. As the design philosophy had pushed towards speed potential in medium conditions, with the emphasis towards seeking an advantage over Kialoa III downwind, the early results were seen as encouraging. When the two yachts were paced against each other in fresher conditions and bigger seas, the speed difference was not marked to windward, with the new yacht showing slightly more heel angle and helm sensitivity, but downwind speed was as expected.
The bigger they are ... (photo Colin Jarman/Seahorse)
Based on early testing results, as well as the fact that the boat still had approximately one foot of rating to play with (within the 70.0ft limit for the Maxi class), it was decided to optimise the speed/rating relationship with a reduction in displacement and an increase in stability. This was made easier through the built-in flexibility within the yacht, with stability-tuning cavities in the keel, and internal ballast being encased in the aluminium sub-structure rather than being glassed in. These changes saw the final rating settle at 69.5ft for the 1981 SORC and Maxi Boat Series.
Kialoa IV and Condor during the California Cup match race series in 1982, which was won by Condor (photo Sobstad sails)
The extensive tuning process had a significant effect on the early performance of Kialoa IV; she went straight into the fray and won races at the 1981 SORC, although there was something erratic about her earliest performances which was to be expected for a boat still at early stages in its development. Initially, and in certain narrow ranges of conditions, both Windward Passage and the Frers-designed Bumblebee IV showed similar speed to the new Kialoa. But Kialoa IV showed her strength over a wider wind range and looked dominant. Although the newest boat, she seemed relatively conservative, and was certainly the heaviest in terms of rated displacement (nearly 84,000lbs, against 70,600 for Bumblebee IV - although for that, Bumblebee carried a near 1% rating penalty).
Kialoa IV in fresh running conditions
However, by mid-season she was more than good enough to win the 1980-81 Seahorse Maxi Series (for yachts rating between 50 and 70ft), and included Ceramco NZ which used the event as a build-up for the Whitbread Round the World Race later that year).  For the most part, Kialoa IV enjoyed close racing with her near sistership, the new Condor, but dominated the series with line placings of 2/1/1/1, and third on handicap (4/1/3/6). During this season, and before the Sardinia Maxi Series (which she won), her main boom (and mainsail) was lengthened by 3ft. This increased her rating closer to the 70.0ft IOR Maxi limit.
Kialoa IV about to cross tacks with Condor (centre) during the 1982 Clipper Cup, with Windward Passage not far behind (right) (photo John Malitte/Sea Spray)
Kialoa IV went on to compete in many international series and regattas, including the 1982 Clipper Cup where she performed strongly finishing as fourth yacht overall (just behind Condor) and helping the US team to an overall victory in the 1982 edition (alongside Bullfrog and Great Fun).
Kialoa IV to leeward and behind Condor during the 1983 SORC (photo Larry Moran)
Kialoa IV won Class A in the 1983 SORC against some new competition, including the new Peterson-designed Midnight Sun and the Pedrick-designed Nirvana, with a combination of good speed and tactics and few gear failures. All the Maxi fleet were well down in the overall standings however, with Kialoa IV managing just 38th within the whole fleet. Kialoa IV finished as second yacht on individual points in the 1984 Clipper Cup (with placings of 5/13/3/3/14), behind the new Frers-designed Boomerang, but ahead of Sorcery, Nirvana and Condor.  
Kialoa IV to leeward of Windward Passage in light airs during the 1983 SORC (photo Larry Moran)
Kialoa IV was often at the forefront of sail development and pioneered the introduction of nascent Kevlar technology at the Maxi scale. Increasing quantities of Kevlar were used to support maximum allowable roach in the mainsail. Dacron was retained in lower sections, presumably for ease of handling, given that cloth weights for both materials were in excess of 8oz.
Kialoa IV with a new Kevlar "crescent cut" no.3 headsail - an article at the time by Hood sailmakers note that "the leech hollow is at absolute minimum to ensure that the foretriangle is full. The no.3 sheets at 8.25 deg and allows full main to be carried at 30 knots apparent wind with the mainsheet traveller two-thirds down the track". Condor (below) opted for the new Norths vertical cut technology (photos William Payne/Seahorse)


The design was a successful one for Holland, and along with sistership Condor, she generated commissions for Round-the-World derivatives Lion New Zealand and Drum for the 1985-86 Whitbread, and the 'inshore' Maxi Sassy, although none of these boats made much an impression on the race course, being shorter than Kialoa and Condor, and heavy for their length. Lion New Zealand did, however, finish second in the 185-86 Whitbread Round the World Race, with greater structural integrity than some of her rivals.
Kialoa IV during the 1983 SORC (photo Larry Moran)

Kialoa IV's reign at the top of the Maxi class was relatively short however, and the decision was made in 1985 for the replacement maxi, the new Frers-designed Kialoa V. She went on to compete in the 1987 Antigua Race Series, before Kialoa V was commissioned in 1988.
Kialoa IV in more recent times, seen here in La Rochelle, France (photo Sail-World)
Recently I was pleased to receive a copy of a fantastic painting of Kialoa IV by marine artist John David Taylor (entitled "Rocket Ship", below). John David was part of the Southern California boating industry throughout the seventies and eighties and had the opportunity to watch Kialoa IV in action during the California Cup match races. He recalls that Kialoa IV was state of the art at that time and left a lasting impression which lead him to become a marine artist (ASMA member). Remarkably, this was his first painting, and was accepted into the West Coast ASMA show (May/June 2017) at the Channel Islands Maritime Museum.

More details (and photos) about Kialoa IV can be seen on the "Kialoa US-1: Dare to Win" website here, and a record of all her race results are here.

A Sail-World obituary for Jim Kilroy is here