High Performance MPX Foil/Self-righting Trimaran-The Test Model

I think everyone's going to have trouble claiming that the use of side-mounted foils to increase stability by creating hydrodynamic lift on a mono is a new idea. It was demonstrated in about 1926; there's documentary evidence about it from a leading designer of the time.

What will happen if anyone fights out a patent case is interesting. The information I found about the 1926 boat is in a document that is now available to the public, if they know where to look.

 

Any chance of you providing a link?

 

Can we assume you're talking about a powerboat? Or have you come across someone who sailed on foils earlier than Gilruth & Carl in 1938?

If it's available to the public, why don't you post it here?

 

Fire Arrow Variation Using Welbourn-type Foils

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I have decided to modify the current Fire Arrow amas with a trunk just aft* of the current uptip ama foils to test the Welbourn-type foil. I'll leave the beam as it is to make up for the difference in movable ballast between the 19.5 ' Fire Arrow and the 14' version with Welbourn-type foils. I want to test these foils on the model before I commit to building the 14' version. I'll be able to use the same quickie molds I used for the D2 to make the Welbourn -type foils for the test. I'm hoping I'll be able to work out doing this model testing and building the full size version before too long.
* Because of the nature of the Welbourn-type foil, this will not change the balance of the boat because the foils do not provide lateral resistance like uptip foils or other types of lifting foils.

 

Fire Arrow Variation and Welbourn-type Foils: Problem

There may be a problem if Welbourn-type foils are used in conjunction with the Fire Arrow mainfoil. The boat is designed to sail with a 10 degree angle of heel(adjustable up to 17 degrees by changing the wand length) and that means that just after takeoff there is a small component of lift to leeward until the mainfoil unloads which it begins to do almost immediately. Only sailing upwind would be affected negatively by this.
For that reason the vertical portion of the ama uptip foil is toed in 3 degrees to compensate.
However, when using the Welbourn-type foil that compenstaion will probably not exist or be reduced somewhat because that kind of foil develops no lateral resistance-or very little. I'll have to study this a bit and decide how important this problem may be and what solutions are possible.
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Soultions:

1-one possible solution that is relatively simple would be to allow the daggerboard to gybe automatically. The effect that would have on the mainfoil would have to be considered.

 

It was a sailboat, but it didn't "foil", as in lift the hull out of the water. It was the use of side-mounted foils to increase stability.

I've spent an enormous amount of time doing historical research on primary sources and writing it up here and in other places, so I think I've done a lot more than my bit when it comes to posting about the history of the sport. I haven't yet had time to be sure I've found out all that I want to know about the craft in question, and (as in other areas) I'm a bit unsure about posting stuff where there are possible patent implications.

 

1926

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Doug, I skimmed Chris's book and didn't see any reference to it. Maybe if you ask nice he'll tell us where it is.
This looks like it could be one of the greatest books ever on the history, design and development of small boat sailing.

 

Maserati Crash!

See here for the story of Maserati's devastating crash:
http://www.boatdesign.net/forums/multihulls/new-trimaran-foilers-55834-2.html#post788747

 

As of 10/21/16 4:31 pm EST all my pictures hosted by Tiny Pic are gone and that site is down.

UPDATE- Pictures back up tonight-8:30pm..

 

Fire Arrow Foiling System Testing and Development / Guillaume Verdier

I found out today that the "idea" for the foil mods to Maserati was Guillaume Verdiers-a well known and innovative designer. So I wrote to him about the Fire Arrow Foil System and about this Design and Development Log.
I expressed my sadness about the collision that Maserati had which effectively ruled out trying the foil system in the Middle Sea Race.
I told him that I thought it was fantastic that he had proved that the basic Fire Arrow Foil System works on a large tri and that I hoped to show how well it can work on smaller sport tri's-under 20'.

 

Guillaume Verdier

Heard back from Guillaume last night and again this morning. He likes the Fire Arrow and might build a similar model! He's going to show the pictures to Mr. Soldini who ,he thinks, will be impressed. Pretty cool stuff from a really first class guy!

 

Well, that's good to hear. Even if they end up doing something a little different, you might be able to share some parts and cut the costs a fair bit.

 

Fire Arrow Foil System / Maserati

What are you talking about?

 

You said, "He likes the Fire Arrow and might build a similar model!" If he does, you might be able to share some parts, at least for your prototype (e.g. amas and ama foils made from the same mould). It simply occurred to me that a more costly route to the final design could be more affordable if the steps taken to get there keep the costs down early on such that you have a working boat to show people sooner which can then attract investment and allow you to replace the shared parts later (with parts which are purely your own design). Alternatively though, you could just focus on making your design so cool that Verdiers decides he'd rather just team up with you to build it.

 

He was talking about an RC model.......