New 30m maxi is launched

Introducing the Brett Bakewell-White designed Zana

The new 30m long Brett Bakewell-White designed maxi, Zana, was launched in Wellington last week for a Kiwi owner, who wishes to remain unnamed.

Brett Bakewell-White gives his perspective on this new project:

As ever with designing monohulls of this size, the main problem is establishing which events the boat is going to do. This is made all the more difficult by the current situation with rating rules and no consensus on where these are headed in the near future. IMS is on the decline in most parts of the world and IRC has limited use outside the UK, Australia, and South East Asia. In this case the owner is not particularly interested in corrected time results and has a belief that the general community can only relate to who finishes first over the line, so this means that speed is the number one objective in this exercise.

Other stated objectives from the owner were the desire to win the Rolex Sydney Hobart race, and a chance to break some of the coastal and offshore race records in the Pacific and then possibly on to Europe. The only one of these events that places any rating limits on the boat is the Rolex Sydney Hobart and an IRC 1.61 limit maxi is always going to be faster than an IMS maxi, so the decision was made. This was further helped by a number of other potential owners making a similar decision and so a new breed has been born.

Traditionally maxi race yachts have been approximately 80ft (or 24m) long and this was still the case with the current IRC boats, which are around 75-82ft in length and in some cases carry water ballast and quite extreme mainsail profiles. Our office had some experience with the yacht Nicorette, designing her new foils prior to her winning the Sydney Hobart race and so this gave us some benchmark data with which to start our analysis.



Above: designer Brett Bakewell-White

Our limited experience with the IRC rule meant that our next stop was the RORC Rating office in the UK to try and get some direction as to what we could and couldn’t do within the rating process in order to establish our design target. They were helpful in supplying certificates for a number of yachts that were either at or approaching the 1.61 time correction limit. We then put this data into a matrix to get some sort of handle on what is happening with the rule. IRC is a ‘secret’ rule and manipulation is strictly forbidden, there is a limit of six trial certificates per year for any one boat within a 2m length range.

Having completed our look at where everybody was currently at within the rule we then set about establishing some basic parameters for our own design. Our starting point was a yacht that was slender and 90ft long. At the same time we also developed a design that we saw as an improvement on Nicorette using the same basic rule parameters - this became our control.

It was our suspicion that water ballasting was treated fairly harshly under the IRC rule and so we ran a VPP comparison with our 90ft boat up against the water ballasted control. In some conditions the new boat was faster - so what would happen if we made it longer still? Inevitably the longer the boat the better the answer, but how would it rate?

We only had six trials so had to be very careful how we used them. Our target design had grown to 29m or 95ft so we decided to trial it and see how the rating turned out. Surprisingly we were still well under the maximum rating, and so this confirmed our suspicions about water ballast. It was our contention that we were better to take additional length and its associated increase in performance in all conditions.

Having confirmed the direction in which we were going to develop the design of this yacht we then proceeded to create some 30 variants and raced them in the VPP, always including our water ballasted control. It has been an interesting exercise working through the development of a yacht of this size and displacement - we have ended up with a hull form that is quite different from that which we expected, and quite different from those that we have developed for smaller yachts even though we have gone through an almost identical design process. During this time we were sending our trial applications to the Rating Office and then factoring the results back into our design process.

So we had reached the end of our trials, we had a long slim boat that looked great, and it is fast - now came the hard bit, holding it all together and finding the equipment to get the boat around the race track with the crew in one piece.

Potential equipment suppliers now became involved in the process of developing sailing systems. The problem faced here is that there are not too many full-blown race yachts of this size prowling the world’s race tracks and so experience in this size gear is limited primarily to the Americas Cup, only we have to take it offshore. Reliability and safety take on a higher priority during sailing and maintenance costs are also a more important consideration.

A further complication for the layout and structure within the yacht is that although we had discounted using water ballast when rating the yacht, we had not abandoned it from the perspective of ultimate performance. For some events the yacht will carry five tonnes of water whilst the keel will shed some 6 tonnes of lead.

Critical structural components have been carefully reviewed by High Modulus and then put through finite element analysis to establish the most suitable solution. This process has been crucial to establishing the most cost and weight effective solutions to various areas of the structure particularly keel grounding loads, and the impact of penetrations through structural components.

The sailing systems and deck layout have been carefully scrutinised and discussed by a number of sailors experienced in both America's Cup and offshore Maxi boats. Various scenarios have been played out so that there have been established methods of handling sails, manoeuvres, and breakdowns. The loads involved are such that it will not be possible for the sailing crew to simply ‘suck it and see’ once out on the water.

Having reached completion now in October 2003, the yacht is about to enter a period of trialling and working the crew up for a tilt at this years Rolex Sydney to Hobart.

There is a huge team of people involved in the creation of this exciting race yacht, and it is a privilege to be involved in such a major event in the New Zealand yachting story.

See our interview with Brett Bakewell-White earlier this year. For a full rig shot - see page 2



Specification

Principle dimensions:
LOA 30.00m 98.43ft
Bmax. 5.25m 17.22ft
Draught 4.50m 14.76ft

Naval Architecture and Styling
Bakewell-White Yacht Design Ltd.

Interior Design
Bakewell-White Yacht Design and Owner

Builder
Hakes Marine Ltd.

Project Management
Starlight Yachting Ltd.

Structure
Zana is built from a mix of wet laminated and pre-preg carbon over Nomex honeycomb core, post cured at elevated temperature under vacuum. The composite structure was designed by High Modulus NZ Ltd. who also supplied a large proportion of the materials in conjunction with Adhesive Technologies Ltd. who supplied the epoxy resin systems.

Spars and Rigging
The carbon spars have been developed and constructed by Southern Spars utilising the latest technology developed from their work in both the Americas Cup and with recent ocean maxi builds.

Sails
Sails are by Doyles NZ in carbon using their D4 technology.

Deck Package
Developed and supplied by Harken Yacht Systems. The winch package is an offshore development of their Americas Cup technology – five pedestals all capable of linking into six different winches with overdrive boxes supplying six speeds.

Hydraulics
Manufactured and supplied by Cariboni of Italy

Mechanical Systems
The installation of the mechanical systems including Yanmar propulsion and water ballast pumping has been developed and carried out by Pizon Marine.

Keel Manufacture
The keel strut is cast high strength steel, cast, CNC milled and heat treated by A&G Price Ltd. The lead bulb was cast by Mike Rees Castings.

Steering System
The high aspect carbon rudder was built in-house by Hakes Marine with various steering components including wheels, steerer units, and trim tab drive box from McConnaghy Boats.