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Articles:



Safety at Sea.

"Heavy Weather Sailing in a Multihull"

Heavy Weather Sailing in a Multihull. Chapter by John Shuttleworth from Adlard Coles - Heavy Weather Sailing, 4th edition.
Heavy weather sailing cover picture click on thumbnail for larger picture


Multihull Design Considerations for Seaworthiness

Novanet Elite in storm

This article is the text of a talk given by John Shuttleworth at the US Coastguard symposium on seaworthiness.

This Paper evaluates how a multihull performs in waves with respect to rolling and pitching. Stability is evaluated both in relation to wind and wave action. In particular reference will be made to Prof. Marchaj's recent work - ' Seaworthiness the Forgotten Factor.' Multihulls are studied under the same criteria as monohulls are evaluated in the book, giving a clear comparison between old and new multihull designs, and monohulls, particularly with regard to capsise in wind and waves. Other factors affecting seaworthiness, such as pitching, surfing, rolling, yawing etc, are discussed. Read more.

An Italian translation of the above article can be found at http://www.cantierino.it/Aarticoli/C-MHSeaVorthness/aaMHSeaVorth.html

Building articles.

"High school project with a difference."

The story of building 2 Shuttle 31 catamarans." 2002
fig-16 thumbnail click on thumbnail for larger picture


"Malihini." by Doug Gibson.

The story of building a 35 ft "Two Hoots" type catamaran in Hawaii and sailing her to the USA and back. (PDF file 760Kb). You need Acrobat Reader to read this article. The article was originally published in Multihulls magazine
malihini click on thumbnail for larger picture


Cruising articles.

Read about Mark and Suze Hicks maiden voyage to the Med followed by a transatlantic voyage in January 2014.

Solea-1-thumb

We got here in two stages. After launching the boat in May of last year (2011) we spent the summer on sea-trails and the endless list of remaining jobs. We planned to leave the UK in July but persistent bad weather held us back until late August when a big crowd finally waved us off from Tenby harbour. .....Read more.

Watch the launch on Youtube of tractor towing boat over fields to river. http://youtu.be/_ZakD3za4sU.


The story of sailing "Zazen" from England to Australia by Alix Pearce. Multihulls Magazine's youngest jouranalist.
Zazen-Muros click on thumbnail for larger picture

Zazen on sea trials in the Solent prior to the voyage.Shuttle 40 Zazen.
Zazen interior and biscay trip photos here."Biscay trip photos."

This is the story of the voyage as seen through the eyes of 12 year old Alix Pearce who sailed to Australia in 2003/4 with her father, mother and twin brother Lorin, plus the odd crew member. This is a unique opportunity to hear it from the children's point of view. the story is in 7 PDF files each about 1 to 1.2 MB.

Part 1. Part 2. Part 3. Part 4. Part 5. Part 6. Part 7.



Sailing a Shuttle 31 through the Abacos islands in the Bahamas.

Shuttle31 click on thumbnail for larger picture
Gladys Cook Schneider sailed with her husband Dale and children Johnny and Daisy, plus nanny and seasoned Bahamas sailor Capt. Jimmy. This is the story of a family adventure aboard the "Eagle"


Technical articles on design.

"The Search for a Seakindly Fuel Efficient Vessel. "Adastra" Winner of the Naval Architecture Showboats Award 2013.

Adastra front page
"Adastra" 42.5 M power trimaran design considerations for fuel efficincy and seakindliness. In recent years there have been a few attempts to find a new solution to achieving low fuel consumption in large ocean going yachts. In this article we will look at the design considerations and compare performances of some of the types of vessel in commission today. We will review aspects of the design of various vessels, not with a view to criticising them, but to show how our thinking has been guided by what has gone before, and then to give our ideas and design concepts on how we have taken up the challenge to reduce fuel consumption and still retain sea kindliness. Finally we will endeavour to demonstrate how successful our solution has been and to explain why the concept has worked so well. Read more.


"Design develoments in high performance cruising catamarans. From the Spectrum 42 to the Dogstar 50." 2002

Pulsar 50
Beyond the Tektron 50. In 2000 I was approached by Peter Bryant to design a new up do date version of the Tektron 50, He wanted a cruiser/racer that could beat the current 40 ft racing trimarans racing in Britain....... Read more.

The same article translated into German can be found at....

Nachfolger der TEKTRON 50 .. DOGSTAR 50

... oder wie man dem schnellsten 50 Fuß-Kreuzer der Welt Beine. John Shuttleworth (bersetzung von Klaus Ehm fur MEHRRUMPFBOOTE, Multihull Deutschland)


The design of a 52ft. Aerorig cruising catamaran

Aerorig52 In July 1995 I was asked by Dr. Ian Munro to design a new large cruising catamaran with an Aerorig. Dr. Munro has retired and and intends to sail around the world over a period of 10 years with his wife as crew. They have been used to a very comfortable standard of living and wish to cruise without a crew to help, and yet want to have many of the comforts of home, like a washing machine, large galley with refrigeration, and air conditioning.... Read more.


 

HULL SHAPES AND RESISTANCE TO MOTION IN CATS AND TRIS

This article appeared in MULTIHULLS VOL.9 NO.1 JANUARY/FEBRUARY 1983 written by JOHN SHUTTLEWORTH.

All yachts must work in harmony with the sea: both in flow and in motion. The boat that does it best, and harnesses the forces of nature to her advantage (rather than opposes them), will surely be faster for it.

Read more from parts : 1  2  3  4


 

MULTIHULLS ON PERFORMANCE

This article appeared in MULTIHULLS VOL.10 NO.1 JANUARY/FEBRUARY 1984 written by JOHN SHUTTLEWORTH.

Over the last few years I have seen many questions (published in various yachting magazines) regarding multihull performance, and as a designer I am invariably asked 'how fast will she go?' and 'what is the weight carrying capacity?'.

Read more from parts : 1  2  3
Charts from article: Fig 1  Fig 2


 

FURTHER DEVELOPMENTS IN PERFORMANCE PREDICTIONS FOR MULTIHULLS

by JOHN SHUTTLEWORTH

Formulae for evaluating light racing boats are examined.

Read more from parts : 1  2  3  4


CAD CAM in Yacht Design

Livery dole
III Livery dole III main
hull CAD

Tremendous advances are being made in Computer Aided Design and manufacture (CAD,CAM) and most important for the normal user, smaller and cheaper systems are available that will run programs previously only available for very large and expensive machines. Read more.



Articles About Our Designs - in order of size.

70 Foot Cruising Cat

70 ft
Cat just launched
Constructed in Cowes, England to the full American Bureau of Shipping approval for plans and building, this 70 ft. cat has been designed to the highest standard, for performance, strength, weight carrying capacity, and comfort. Mike Schicht was chosen to head the building team because of his extensive composite building experience using vaccuum bagged laminates. Read more.


Reflections on the Design of "Brittany Ferries G.B." 65 ft. Racing Trimaran for the two handed transatlantic race

Brittany Ferries

A talk by John Shuttleworth at the Multihull Offshore Cruising and Racing Association A.G.M., January 1982.

Various articles have been published about the boat over the last year explaining many of the design features (see Multihulls International Dec 1980). So rather than go over old ground I thought tonight I would just outline the general design principles and then concentrate on the outrigger design and introduce some new concepts regarding the relationship between wetted surface area and speed. Then I would like to show why Brittany Ferries G.B. was faster than Elf Aquitaine and finally have a look at the future and try and indicate the direction I think design is going to take. Read more.


The design of a 52ft. Aerorig cruising catamaran

Aerorig52 click on thumbnail for larger picture
In July 1995 I was asked by Dr. Ian Munro to design a new large cruising catamaran with an Aerorig. Dr. Munro has retired and and intends to sail around the world over a period of 10 years with his wife as crew. They have been used to a very comfortable standard of living and wish to cruise without a crew to help, and yet want to have many of the comforts of home, like a washing machine, large galley with refrigeration, and air conditioning.... Read more.


"Design develoments in high performance cruising catamarans. From the Spectrum 42 to the Dogstar 50." 2002

Pulsar 50 click on thumbnail for larger picture
Beyond the Tektron 50. In 2000 I was approached by Peter Bryant to design a new up do date version of the Tektron 50, He wanted a cruiser/racer that could beat the current 40 ft racing trimarans racing in Britain....... Read more.

The same article translated into German can be found at....

Nachfolger der TEKTRON 50 .. DOGSTAR 50

... oder wie man dem schnellsten 50 Fuß-Kreuzer der Welt Beine. John Shuttleworth (bersetzung von Klaus Ehm fur MEHRRUMPFBOOTE, Multihull Deutschland)


Tektron 50

Tektron50-photo click on thumbnail for larger picture

This summer sailors on Lake Ontario will see an exceptional new multihull take to the water. This Catamaran, which has been built near Toronto, pushes back the boundaries of performance cruising further than has ever been attempted before. Furthermore this boat is intended as a test bed for an exciting new range of yachting instruments of manufactured by Tektron Equipment Corporation, and will therefore provide more data than has ever been gathered on a multihull before, in terms of rig and hull stress against performance on all points of sail, and sea states. After tuning up on Lake Ontario, the Tektron 50 is entered in the 1988 Quebec-St Malo race. Read more



Spectrum 42

Toucan-sailing Timshel_at_dock click on thumbnail for larger picture
Adapted from and original article in Multihull International 1985

The initial response to this cat in my original article in Multihull International has been excellent. This boat is built with the same high tech concepts as my best racing designs, many new techniques were developed to speed up the building process. 15 years on from when this boat was first launched, several have been built and a number have made ocean crossings. We are all very excited by the performance. She meets all my expectations. Pitching is very well controlled, and the boat trims slightly bow up on a reach as designed.... Read more.



PowerShuttle 40

POWERSHUT40 click on thumbnail for larger picture

The new Powershuttle 40 has been designed as an economical, environmentally friendly catamaran. Utilising the new 90 or 130 HP Honda 4 stroke outboards extraordinary fuel economy can be achieved when compared to conventional power boats, and yet the Powershuttle 40 has more accommodation, including a huge shaded cockpit, and dive platform aft. The dive platform hinges down to the water to provide easy access. Steps up the transom make boarding easy. Read more.



Tektron 35

Tektron35 click on thumbnail for larger picture
One of the main aims of this new design was to produce a boat boat with comfortable living accommodation space with as little sacrifice as possible to sailing performance, windward ability and seakeeping qualities . This 35 ft Catamaran exemplifies the new generation of performance cruising multihulls, designed and engineered with the latest thinking on structures and computer designed hull forms. The boat is nevertheless suited for skilled amateur construction. the first production version is currently under construction in Canada by Eugene Tekatch, who built the Tektron 50. Read more.


Read the article from Mulihulls world on the Tektron 35


Read the article written by Don Peaslee on the Tektron 35


Tek 35 specifications.

T35-aft-view-thumb click on thumbnail for larger picture


35 Foot Catamaran for Home building "Two Hoots" design

Malahini

Many people wonder about what the benefits of ocean races are to ordinary sailors. Races like the OSTAR and La Route du Rhum, where enormous sums of money are spent on the latest technology, materials, and systems, to assist the shorthanded sailors to sail the boats as fast and as safely as possible. Yet, in the fast moving world of multihulls I believe that it is possible to see a direct correlation between the money spent on developing high-tech race boats and cruising designs. This catamaran is an excellent example of such a boat... it is the payoff for the cruising multihull. Read more.



Shuttle 31 Catamaran

S 31 Eagle 31ft Foam sandwich or wood epoxy racer cruiser catamaran.

This 31ft catamaran is part of a range of fast cruisers which developed from the highly successful Spectrum 42. Designed and engineered with the latest thinking on structures and computer designed hull forms, the boat is nevertheless suited for skilled amateur construction. The first boat is currently under construction in Brazil by Multimar, built from PVC Foam Sandwich with E glass and polyester resin, although the design lends itself equally well to wood epoxy construction. Read more.



"Wood Epoxy Shuttle 31 Catamaran."

The story of building 2 Shuttle 31 catamarans." 2002.
fig-16 thumbnail click on thumbnail for larger picture

In July 2000 I received an order for a set of plans for a Shuttle 31 to be built in Western Red Cedar strip planking with Epoxy and glass reinforcing. I had been in correspondence with the teacher of a group of young people at a Waldorf (Steiner) school in Switzerland. This teacher, Thomas Wolf, intended to head up a team of 12 students with the aim of building two 31 ft cats in less than two years. At the start of the project the students wrote to me "We are twelve students at the age of 16-17 years. We attend a Waldorf school in Muttenz, Baselland. Two afternoons per week we work at the boats. While our schoolmates attend special courses like working on a farm, we will solely concentrate on building the boats. Also during the holidays we will sacrifice some weeks for the project." Read more.



30 Foot Racing Tri "N'aia" for Mike Reppy

Naia After winning class 3 in the 1988 CSTAR in Damiana, the 42ft Tri. I had designed for him in 1982, Mike decided to try and raise money for a bigger racing boat. In the meantime he would build a 30ft racer as a test bed for some new ideas. Initially we started with and all out day racer for San Francisco Bay, but soon Mike decided that he wanted to do the Transpac as well, and that the boat should be demountable so that he could ship her back from Hawaii.

I had already designed two successful 30 ft offshore racing trimarans, Caledonia, which had knocked over 6 days off the transatlantic record when winning class 6 in the '88 CSTAR, and Shockwave. Shockwave was definitely faster than Caledonia, but when Mike talked about a new boat I had a hunch that by doing some thorough research and incorporating my latest ideas on rig efficiency, we could make another significant leap in performance. Read more.



Designers Comments on "Shockwave". 30 ft Racing Trimaran for the around Britain and Ireland race.

Shockwave Built for John Fowler by Dave Irving at Queen Anne's Battery in Plymouth in vacuum bagged polyester and E glass, with carbon reinforcing in the main hull, Shockwave is designed to win the 30ft Class in the forthcoming Round Britain & Ireland Race. Shockwave is a development of the extremely successful Caledonia which was amateur built and sailed to a record Class VI win by my design assistant, Rod Stuart, in the 1988 C-Star. Read More.



  • Ian Holt review of the Lynx 8 metre Micro multihull
  • lynx_thumb.jpg Part 1 (180k)
    Part 2 (147k)
    Lynx Study Plan (129k)


    Published Articles About Our Designs and Theories.


      Shuttle 47 Catamaran Boat Test.

    Life's a Dream - Shuttle 47 Catamaran Boat Test.

    This article was written in Sailing Magazine in South Africa soon after the launch of Life's a Dream in Cape Town.


     

    KILLING ON DESIGN BY STEVE KILLING

    Tek-35 Racer/Cruiser Catamaran
    True composite boat with double hull pleasure

    This article appeared in Canadian Yachting Magazine Winter 2000

    My design reviews in Canadian Yachting are normally based on drawings alone. Since the comments focus on the merits of the design philosophy, visiting or sailing on the boat is not a pre-requisite. However, Eugene Tekatch convinced me to come down to see his newborn (but no long in gestation) Tek-35 Catamaran, and it was a good thing that I did. Although I had access to the original drawings, after five years of development and building three custom versions of the boat, the deck, sail plan and interior had all significantly changed. It was important to see it in its final configuration. I was very intrigued by the construction process - there was no way I could have imagined its detail and complexity. Read more


     

    CRUISING "CATTLEYA"

    Our Search, Our Goal By JEAN and MITCH LEAVITT

    This article appeared in MULTIHULLS January/February 1997

    It was time for a change. We both wanted to do something different. Eventually my wife Jean and I decided it was time to go cruising, rather than wait until retirement to fulfill that dream. Once we made the decision to break away it seemed like such an obvious decision, we wondered why it had been so hard to reach. Two years earlier we had sold our 35' monohull. We loved the boat, but had too little time to use her. Now we needed a boat for extended cruising. Read more


     

    TEKTRON 35:
    THE MULTIHULL OF THE THIRD KIND

    This article appeared in MULTIHULLS World N° 47 July 1993 featuring a TEST review of the TEK35 written by François Richard.

    In many ways the Tektron 35 is a very special catamaran on the more and more creative and productive market which is currently offered. Seen in La Rochelle in September 92 during the Grand Pavois show, this catamaran of the third kind will not in principal break any sales records but has the potential to please those enthusiasts who do not find what they are looking for in current cruising multihull catalogues. Read more.


     

    MAIDEN VOYAGE - TEKTRON 35E

    CN Tower to Bermuda

    This article appeared in MULTIHULL INTERNATIONAL VOL.25 NO.295 AUGUST 1992 written by ALISTAIR WOOD.

    THE FIRST EUROPEAN specification Tektron 35E looked superb floating by the dock at the Royal Hamilton Yacht Club as the delivery crew arrived in Canada for the start of an epic journey to the Mediterranean via the inland waterways to New York. Owned by Katamaran Konstructions GmbH, the Vienna based European agents, Tektron was to undergo the ultimate test: a Transatlantic passage en route for the La Rochelle Boat Show in September of this year. Read more


     

    Fast Cruising Cat .....
    TEKTRON 35

    This article appeared in MULTIHULL INTERNATIONAL VOL.23 NO.264 JANUARY 1990 designed by JOHN SHUTTLEWORTH.

    ONE OF THE MAIN AIMS of this new design (writes John Shuttleworth) was to produce a boat with comfortable living accommodation space with as little sacrifice as possible to sailing performance, windward ability and seakeeping qualities. Read more


     

    Tektron 50 yacht design

    This article appeared in MULTIHULL INTERNATIONAL VOL.21 NO.241 FEBRUARY 1988 written by JOHN SHUTTLEWORTH.

    This summer sailors on Lake Ontario will see an exceptional new multihull take to the water. This Catamaran, which has been built near Toronto, pushes back the boundaries of performance cruising further than has ever been attempted before. Furthermore this boat is intended as a test bed for an exciting new range of yachting instruments of manufactured by Tektron Equipment Corporation, and will therefore provide more data than has ever been gathered on a multihull before, in terms of rig and hull stress against performance on all points of sail, and sea states. After tuning up on Lake Ontario, the Tektron 50 is entered in the 1988 Quebec-St Malo race. Read more


     

    Multihull Design Considerations for Seaworthiness

    MULTIHULLS VOL.14 NO.1 JANUARY/FEBRUARY 1988 written by JOHN SHUTTLEWORTH.

    This Paper evaluates how a multihull performs in waves with respect to rolling and pitching. Stability is evaluated both in relation to wind and wave action. In particular reference will be made to Prof. Marchaj's recent work - 'Seaworthiness the Forgotten Factor.' Multihulls are studied under the same criteria as monohulls are evaluated in the book, giving a clear comparison between old and new multihull designs, and monohulls, particularly with regard to capsize in wind and waves. Other factors affecting seaworthiness, such as pitching, surfing, rolling, yawing etc, are discussed. Read more.


     

    MULTIHULLS ON PERFORMANCE. 35 Ft. Catamaran "Two Hoots"

    This article appeared in MULTIHULLS VOL.11 NO.1 JANUARY/FEBRUARY 1985 written by JOHN SHUTTLEWORTH.

    Many people wonder about what the benefits of ocean races are to ordinary sailors. Races like the OSTAR and La Route du Rhum, where enormous sums of money are spent on the latest technology, materials, and systems, to assist the shorthanded sailors to sail boats as fast and as safely as possible. Read more :