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The
Design History Designing PlayStation started with Steve Fossett's simple request to investigate the best boat for racing fully crewed, non-stop, around the world as fast as possible. We assumed that the boat would be built of the best materials available and that it would be built with state of the art technologies, allowing us to design and build this boat slightly lighter in comparison to other existing large multihulls yet with much more sail area. We started out with some assumed limitations to this design quest. The boat had to be sailed with only people to power the winches, so human capabilities effectively limited how big we could design. We also did not want to design a boat that required new winches to be invented. Since we wanted to sail with a relatively small crew, the number of hands available at any time to turn the winch handles limited the design. We also needed to design within a budget, so overall cost would have to be considered a leading factor. Two Hulls or ThreeGino had previously worked with a friend Clay Oliver during the 1988 America's Cup campaign where they developed a computer automated VPP (Velocity Prediction Program) for catamarans. Clay had been a principle designer in Dennis Conner's design team of "Stars and Stripes", for the 1988 America's Cup in San Diego. This velocity prediction program helped us develop the 60 ft Stars and Stripes catamaran, which we eventually built to successfully regain the Cup in the race against the New Zealand challenger "KZ1". Again, we worked with Clay to extend the program's capability to analyze trimarans as well as catamarans. Since we had access to Steve's other boat "Lakota"--a 60 ft trimaran--we were able to verify the program's accuracy by comparing the numbers the program predicted against the actual performance we were able to measure while sailing "Lakota". At this point we knew we had
a program that was accurate up to the 60 ft size before we ventured
off into analyzing 100+ foot trimarans and catamarans. The VPP then
allowed us to input hundreds of boat variables such as beam, weight,
hull dimensions, sail areas, and daggerboard and rudder sizes. This
helped us to theoretically design several boats, with slight variations
and race them against each other in the computer using true wind histories
of any given race course. This computer simulation would allow us to
determine which design would be more favorable. |
Weather and WindAs we were primarily interested in around the world racing we had to find and create race histories or test cases to race in. We gathered together weather data from several sources, including data from the previous Whitbread monohull races around the world. We incorporated the data from the previous Jules Verne's around the world runs of Bruno Peyron's "Commodore Explorer" and Peter Blakes "Enza" as well. We developed five different weather case studies to work with. As the wind is never the same, some of these cases represent windier runs and lighter air runs, with different percentages of upwind, reaching and downwind sailing. The boat that won one scenario may not have won another, so the goal was to try and find the best candidate that had the highest probability of winning the greatest number of the times. Our computer races also showed us the relative importance of length vs. beam vs. sail area vs. weight. After finding the fastest boats within a certain set of parameters we continued to fine tune this group until one well as their concerns and desires for the new boats details. We spent many days and evenings discussing in minute detail all manner of potential problems and pitfalls of various issues. Simultaneous to developing ideas for the concept, Pete tore into the structural design and engineering of the boat. His initial analysis determined the first broad-strokes of what the boat would need to be built of. Several technical issues surfaced and required NASA's technical services to shed light on issues of material natures that ocean racing yachts had never experienced before due to the size and the enormous loads this boat will be capable of generating. We held several meetings with Steve, Ben, and Brian over the course of the design process--even some during various boat races. Gino and Pete have crewed for Steve on both Lakota and Stars and Stripes for some of their record-breaking runs--Transpac, the Ensenada Race, Swiftsure, and Cabo San Lucas. These races provided them with many hours to get to know each other and learn each of their individual racing techniques. A number of ideas were developed on these races, some at 2:00 am on windy cold nights… |
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Building Plans CommenceAfter ball-parking a few budgets and reviewing the general strategy, Steve gave the go ahead to proceed to developing the preliminary bid package based upon our consensus catamaran design. Once we developed a preliminary package of drawings, depicting the general layout with each structural element coarsely detailed, Steve had us circulate the drawings to three of the worlds most renowned builders. After some spirited negotiations, Steve chose to go with Mick Cookson of Cookson Boats in Auckland, New Zealand. Shortly thereafter, Peter Wilson of MCM, Newport RI USA was brought into the team as Project Manager. Peter has been involved in several America's Cup programs including Bill Koch's successful 1992 America's Cup campaign. His expertise in managing a globally developing project was gladly welcomed. Once Peter was on the job, several major components were put out for bid. Southern Spars, in New Zealand was awarded the task of creating the mast, while Lewmar Marine, of England, became responsible for the winches and deck hardware. The team of CMI, YLA, and High Modulus was awarded the job involving structural materials. Finally, North Sails was awarded the task of building the sails. We did some initial work ups with Mike Schreiber of North Sails to predict the loads of the immense sail plan envisioned. We again took the opportunity to have Mike predict the loads on "Lakota" with his sail design software. Since they had built several sails for the boat they had firsthand knowledge. After measuring the loads on "Lakota", comparing Mike's predictions and our predictions, with only minor adjustments we again got everyone's programs to accurately reflect the reality of "Lakota's" sailing loads. We then ran many cases with Mike to predict the loads of the various sail configurations for the new big cat. This information became part of the structural foundation, enabling us to utilize one of computers' biggest benefits to structural design, Finite Element Analysis.
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Stronger, Lighter and SafeFinite Element Analysis (FEA) is an engineering analysis technique that, in the hands of a skilled engineer, can predict stress and strains within a structure to surprising accuracy. Kurt Jordan of Mill Valley, CA is one of the world's most skilled at using a computer FEA program in composite structures. We had only used FEA for specific parts on other previous race boats. In the past, due to computer hardware limitations, only relatively small models could be analyzed with any precision in a reasonable amount of time. Due to the decreasing cost of computers and the simultaneous increase in speed, projects such as ours without military size budgets could now analyze fairly large structures in their entirety with microscopic precision. The benefit of this increased analysis is the ability to tune the structure so that consistent levels of safety margin can be maintained throughout. Like a chain that is only as strong as it's weakest link, designing an enormous ocean racing catamaran to make sure all it's links are equally strong was our goal. We were able to fine-tune the laminates in each part to maintain minimum weight, maximum strength, and consistent factors of safety. We embarked on a material test program to verify that the numbers used in the FEA were indeed achievable on the shop floor. Cooksons built several test panels using YLA materials and various structural cores, Nomex and aluminum honeycomb and end grain balsa core. After many rigorous tests and technical sessions a base laminate and material was determined and ordered. |
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Structural ModelsPete worked closely with Kurt, setting up the test cases the structural model had to endure to simulate bone-jarring pounding, racking and capsizing. By subjecting the computer model to these extreme situations we could find the weak spots in the hulls and beams and increase their strength until a uniform factor of safety was developed. We carved away material and structure in areas that did not need it. By this methodical tailoring, Pete and Kurt combed through the process layering the precious carbon fiber just where and how much was needed. This process was more time consuming and valuable than initially expected. We are delighted with the outcome and confident the structure has been engineered to unprecedented levels for ocean racing multihulls. In the meantime, Robert Favier began shaping the hull and developing engineering programs to size custom rigging and determine electrical loads. The latter allowed us to fine tune the most effective way to minimize tradeoffs in efficiency and weight for proposed solar panels, gensets, batteries, wind generators, and fuel given estimated days at sea. By choosing High Modulus
of New Zealand to supplement our own CAD drafting team, we were able
to benefit from their close proximity to the building site. Located
only minutes from Cookson Boats they were able to be a close conduit
for us as we hammered through countless details, and discussions on
how to build the detailed structure Pete was putting together, with
Mick Cookson and Paul Hakes. Pete traveled to New Zealand as the first
hull was being built to verify all was going well and work out on site
upcoming technical issues. We came to appreciate Cookson's team
of skilled craftsman for their work as well as their great sense of
humor. |
Competition Joins InIt was ironic that so many New Zealanders and British who had raced against us so fiercely with "KZ1" in the 1988 America's Cup were now helping us manage, design, and build our big cat. Peter Wilson had been project manager, High Modulus had engineered the boat, Cooksons had built it, and Southern had built the mast. The teaming of this group has resulted in many exchanges and good-hearted ribbing. The FEA analysis was crafted
into construction drawings and passed to the builders. The process required
several reviews by all involved and at times required many revisions
as new techniques, materials or ideas became
available and required prudent consideration. This process, while slower
than envisioned, was worthwhile and the end result we feel will be a
racing yacht capable of racing many years in the worlds most extreme
conditions. When considering the isolation the boat will race in, the
demanding Southern Ocean, as well as the frigid North Atlantic, it is
mandatory to do everything reasonable to assure no stone has been left
unturned in pursuit of designing and building this extreme racer. |
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Weather and Technology ExperienceSteve reviewed drawings and ideas as they developed. His experience in ballooning, weather forecasting and monitoring led us to incorporate many of the same facets into the navigation area. Steve made sure we incorporated the latest technology available in computer monitoring the weather as well as rigging loads and boat performance. We installed a special pod of instruments in his berth area so that at all times he can be aware of what is going on. All during the construction, we followed the progress by Emails and regular phone calls. Gino visited Cooksons with Ben Wright for a week as they were assembling the platform into one big piece for the first time. They hammered out many details and reviewed work being completed. Shortly thereafter, Ben returned permanently and took on the responsibility of seeing to all the last minute details. He regularly sent us digital photos of the boat via email, which helped resolve questions much more efficiently. As we near the launch we
look forward to the sea-trials and the first forays into the ocean.
Time will tell if we have done our job well. In any event, we
know we have learned a lot from each other and have developed a strong
feeling that there will be some extremely exciting sailing to come… |
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