Is rigidity a religion? Amas on the move....

Discussion in 'Multihulls' started by Qmaran, Aug 31, 2021.

  1. guzzis3
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    guzzis3 Senior Member

    Owly: I am both. I did my apprenticeship as a motor mechanic and studied engineering at night. I understand what you are saying but it's not 100% right. The problem is there are lots of people out there who think they know. Some have a piece of paper some don't. What they all lack is experience.

    Land rovers have rigid chassis. They carry obscene loads and don't break. It isn't just a question of rigid vs flex it's about proper engineering having both the theory and the experience to make good calls. It's also about knowing your limitations and when to ask someone who knows what you don't.

    Wharram and Piver promoted multihulls when no one knew much about them and how things would work. They played an important role getting us where we are today. The trouble with Wharram is he refused to move with the times. His boats have gradually improved but his stuff is a good 20 years behind what more open minded people are offering. The designers I mention above have both got formal marine design qualifications, but the also draw on practical experience. They both build boats, they both sail them. Wharram obviously built his boats and sailed them but he seems to be more of an "artist" than an engineer and "feeling" and "believing" is no substitute for knowing. The Wharrams I am familiar with are incredibly wasteful of materials and time to build and when your finished you have a boat that is an average performer at best and has no resale value. So you've wasted hundreds of hours of your life building something mediocre at best when you could have built something good for the same money and effort.

    Anyway off topic...sorry.
     
  2. gonzo
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    gonzo Senior Member

    There are thousands of Wharram boats with flexible connections that have been cruising successfully for decades. Can you provide any links to flexible hull connections on his designs that failed when they were not modified?
     
  3. Michael Farmer
    Joined: Aug 2021
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    Michael Farmer Junior Member

    Well put I agree about lighter and stiffer structure, weight is detrimental to multihulls. My point is that some flex between the main hull and amas would be beneficial in a sea way. This seems to be supported in the Gougeon brother Tri design posted by Garry Dierking (post 12), he might have describes it as suspension where I used the term flex of ama to the hull. Indeed Garry Dierking has used similar flex in Va''a Motu design.
     
    Last edited: Sep 8, 2021
  4. gonzo
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    gonzo Senior Member

    Wharrams were originally designed to use small section lumber of medium quality. Also, the plywood on the hull is used in whole sheets with little cutting. Further, they have a cult following and the proof is that few are for sale, and those who are don't stay on the market for long. I understand you don't like Wharrams, but your statements have no basis on fact.
     
  5. Russell Brown
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    Russell Brown Senior Member

    I've never sailed on a Wharram, but I have to agree with Guzzis except for the money and effort part. They are pretty simple.
     

  6. Clarkey
    Joined: Aug 2010
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    Clarkey Senior Member

    Land Rovers are prone to chassis failures, particularly the 127 and 130 variants.
     
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