Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Yachts and Sail => Topic started by: Bugsy on October 04, 2009, 03:35:05 pm
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from the IOM boat hull measurement form.
"Is the largest transverse dimension greater than 20 mm measured
at any point 60 mm or more above the lowest point of the keel?"
Can anyone explain exactly what this means in normal english please.
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With 65 views and no answer I guess its not just me who doesn't understand it then O0
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If you tell us where this comes from it might help to make sense of it if we see it in the original context.
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http://www.iomclass.org/class-rules/
E.4.1
I think it means "thou shalt not have a fat fin". It also limits the depth of the ballast weight, effectively keeping it a simple shape. Fairly effectively.
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I have moved this topic to Yachts and Sail in the R&D section to see if you get a better response. And it will easier for others to search in the future.
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If you tell us where this comes from it might help to make sense of it if we see it in the original context.
There is a clue in my first sentence ok2
"From the IOM boat measurement form"
malcomfrary.
Thats how I read it but its not very clear, well not to a 'thicky' like me anyway.
Thanks.
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There is a clue in my first sentence ok2
"From the IOM boat measurement form"
And thanks to Malcolmfray we now know where that form comes from. ;)
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There is a clue in my first sentence ok2
"From the IOM boat measurement form"
malcomfrary.
Thats how I read it but its not very clear, well not to a 'thicky' like me anyway.
Thanks.
That may be a clue, and it may mean something to you but it may mean a lot less to most of us. I can assure you it means nothing to me and IOM is far more likely to read as 'Isle Of Man' to most people.
Thanks to Malcolm for the clarification.
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Ooop's, my mistake, I never set out to argue with or upset anyone.
I just figured that on a boating forum I.O.M. (International One Metre) would be understood by all, clearly not.
I will endeavor to post questions critically clearer in future.
.
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This is from the rules:
E.4 KEEL
E.4.1 DIMENSIONS
minimum maximum
The largest transverse dimension except for the
lowest 60 mm .......................................................................... ....... 20 mm
So no minimum thickness for the keel, you could make it 1mm thick if you wanted to and could get it stiff enough, but no thicker than 20mm.
Origin:
1610–20; < L trānsversus going or lying across, athwart. See....
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Thanks Islander :-))
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are you building an IOM yacht hull or making a new keel or fin?
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are you building an IOM yacht hull or making a new keel or fin?
Planning a winter project a 'scratch-built IOM yacht hull.
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Mmm, nice I race IOM yachts myself are you going to build it from one of the designs that can be purchased as plans or will it be wood structure or are you thinking of making a mould .
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From a plan with plank on frame I'm thinking as I've never done this type of construction before. I've built a few planes but have got a bit fed up with picking up the pieces in a bin bag O0
A couple of questions, there will no doubt be more ok2
What wind strengths do the different rig and sail sets cover?
What is meant in the rules by the "deck limit mark" ?
Gary.
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This is from the Rules:
D.1.5
Is there a deck limit mark, of 5 mm min diameter, displayed on the centreplane of the hull near to the mast position?
This is a datum point from which rig measurements, etc., are taken.
On my boat, it's under the gooseneck.
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What wind strengths do the different rig and sail sets cover?
Gary.
That's not an easy answer you'll need all three rigs to cover all weather conditions I sailed in the Rankings this weekend and we were using number 3 rig the wind was up to 40mph at times. Then the next day it was a nice breeze so everybody was using number 1 rig it's however much you can control the boat that decides the rig to use.
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Agreed, I use A rig from 'Can' up to 'Can't' , and then change down to B...... :D
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What wind strengths do the different rig and sail sets cover?
When your wrist gets sore trying to hold it on the bank, you should have put a smaller set on.
The range of wind speeds that different suits are good for varies with the boat, how you set them, and sometimes on wind direction - this last can change surface conditions and give you effectively a different boat to learn. Such is the lasting interest of yachts.
Otherwise, islander has it spot on.
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Thanks for all the advice.
What percentage of use do you racers use your different rigs?
Money is a bit tight at this time and I will, initially, only buy one rig.
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Thanks for all the advice.
What percentage of use do you racers use your different rigs?
Money is a bit tight at this time and I will, initially, only buy one rig.
The B rig is probably the best to learn with. It will work in a wide range of conditions and is relatively easy t o get a satisfactory working setup. It won't have as much performance in light airs as the A rig, but you will learn a lot about sailing in light airs with the reduced power. Sailing in uncomfortable conditions (C rig) can wait.
Not being a racer, My A rig has hardly seen the light of day as in those conditions my small electric boats come out to play.
If cash is tight (been there, done it, borrowed the book etc) you could consider making your own. A big sheet of hardboard, sellotape, a sharp knife, polythene sheet and a spare soldering iron can produce sails good enough to learn on at very low cost before laying out serious cash.
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I like speed, so my A rig gets the most use.
This is mostly due to the fact that our pond is surrounded by trees so we seldom get good steady hard winds, so it is only occasionally that conditions are good enough for the B rig,but when that happens, it's a blast!! :D %)
The B rig is more versatile and can handle a greater range of conditions, but it's severely disadvantaged in lighter airs.
I would buy a good A rig, and invest a bit of time and effort in making a B rig; polyester film is cheap and available from PJSails, as is the double sided tape for joining the panels.
Even if your first effort is a bit heavier than it should be, when you need this rig the wind will be strong enough that it doesn't matter. :-))
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Referring back to the 20mm question, last on post#9 in this thread. the 20mm is to prevent owners from building in a large faring radius onto the keel just where the keel enters the hull. If this was very large, and very lightweight fillers were used, then this could add boyancy as well as streamlining to the hull. Remember the keel/fin MUST remain removable so that it can be independantly weighed and adding a faring to it in close proximity to the hull skin has to be controlled, and so the 20mm max width.
Ralph
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any more pictures of the IOM yet?
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Yes, finished but not yet sailed (iced up lake)
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That looks good, except for the bulb, which I don't like the look of !
What design is it?
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Its all on here Islander,
http://www.modelboatmayhem.co.uk/forum/index.php?topic=21084.0
Following comments from SCM I have already moulded a new bulb, it just needs finishing.
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Thanks.
Note to self: Ensure that brain is fully engaged before typing anything. {:-{
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that's a very nice boat and should perform as good as she looks. I have recently purchased a new IOM I thought you might like a look at her.
(http://static.rcgroups.com/forums/attachments/6/7/1/0/4/t2978305-137-thumb-011.jpg?d=1262989940)