Yacht performance comparison

Discussion in 'Sailboats' started by Wardi, May 19, 2004.

  1. Wardi
    Joined: Nov 2003
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    Wardi Senior Member

    I am conducting a study of the design performance improvements in yachts over the past 30 years and am after comparative data of real performance and the basic proportions of each yacht.

    I have found a nice resource of data at http://www.yralis.org/
    under "Handicap Racing Information with Rating Froms" , "Base Ratings".

    I now have data on over 4000 boats with their basic dimensions and actual performance rating. The results of initial comparisons is very surprising!!

    Most of the boats covered by this data are standard yachts 20-60ft from a wide variety of manufacturers. Unfortunately there is not so much information on the very latest racing craft such as Open 60's, V60, V70, Maxis etc or one designs like Mumm36, Farr40, Sydney38 etc.

    Does any anyone know where I can get data for these types of craft?
    Ideally I am after: Displacement, LWL, Sail Area, Beam, Draft, Ballast, Age, rating and most importantly a measure of their actual speed, ie: from actual race results, not just their IMS or IRC handicap, but this would also be useful. ....In a spreadsheet would be ideal!!
     
  2. Jeff H
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    Jeff H Junior Member

    There are other PHFR sites that include detailed information on various boats that are rated within their region. www.yachtworld.com also has a lot of information within the listings on that page. Designer's websites like Farr International, and Groupe Finot contains a lot of information on custom one off boats like Volvo 60's, Open Class 60's, and one designs like the Mumm 36 and Farr 40. Since the IMS is a VPP based program it is actually a pretty good source of relative boat speeds. What it can't rate is the tactical advantages of a faster boat in placing itself where it needs to be on the race course.

    Jeff
     
  3. Wardi
    Joined: Nov 2003
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    Wardi Senior Member

    Thanks for the tips,
    Unfortunately I cannot find much useful performance comparison data here, as they do not have any rating or performance data.
    I suspect the IMS rule people and developers of VPP should have such data, otherwise how could they know if their methods reflect reality? So far I have been unsuccessful by contacting them via official channels.

    Does anyone have any direct contacts who may have access to this information? :?:

    I am also hesitant to use VPP results alone, as these only tell us what theory says the boat should be able to achieve. It does not tell us what the boats acually achieve, which is the real test of a real performance improvement.
     
  4. Stephen Ditmore
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    Stephen Ditmore Senior Member

  5. guest12020101217
    Joined: May 2003
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    guest12020101217 Junior Member

    For info on designs like Mumm36, Farr40, Sydney38 etc, try contacting owners in euorpe and Oz and ask for copies of there IRM and IMS certificates. You will find contacts by searching for owners personnel websites for there boats.
    i.e. Mumm 36 Team Rocket etc etc. Class website will also help in this. If you talk nice to the rating offices you may get one or two free copies but normal you have to pay to get them.

    To start you off you will find in the attached zip folder the following,
    Scan of a IRM certif
    Copy of 2000 IRM rules
    Blank IRM spreadsheet
    IRM spreadsheet for Farr 40, Ker 11.3 Farr 52 and IC45
    And a spreadsheet with odds and ends.
    Try the Farr website. Ita been abit since l last visited it but it should have copies of basic IMS certif's on it. If not l may have a old Farr 40 IMS certif on a disc somewhere!

    Hope useful
     

    Attached Files:

  6. ErikG
    Joined: Feb 2002
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    Location: Stockholm, Sweden

    ErikG Senior Member

    Hijacking

    I beg your pardon Wardi that we hijacked your thread for a while :)

    The IMS discussion has now been moved into its own thread at: http://www.boatdesign.net/forums/showthread.php?t=3779

    This first of my original posts was just to let you know that there are more than meets the eye when u talk about IMS boats.

    ErikG
     
  7. Wardi
    Joined: Nov 2003
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    Location: Sydney

    Wardi Senior Member

    Firstly many thanks for your efforts with providing this information. I am now including this data in my analysis. I is quite useful!

    The one factor which seems to be missing in all the data I can find is the "actual" performance of the boats, as opposed to the "calculated" rating. The reason is that this should distinguish the best designs. I presume this can only be found from race results, and that the best sources are clubs and rule administrators. I am trying these sources but am not getting any feedback, so I am still after some good data.

    On IMS, I am quite sure there is a lot of truth in what Erik G says about their relative performance. Stability is generally very low!

    One question begging to be posed in this discussion, is:
    "What should be considered a suitable basis upon which we can evaluate fundamental performance improvements?"

    It is quite clear that Speed/Length ratio is the norm used by most casual observers, but we all know that displacement and sail area contribute significantly. So shouldn't a proper comparison be based on all of these parameters?
     
  8. Jeff H
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    Jeff H Junior Member

    I think that it would be a major mistake to say that, the 'Stability [of IMS boats] is generally very low!'

    While I am not sure what is happening in European IMS 600, and unless something has suddenly changed very radically with IMS rule, up until recently IMS boats have had extremely high stability, especially when compared on a overturning moment to displacement basis. I think you would be hard pressed to find a performance design from any era that would approach the high stability of IMS boats and in fact it is their high stability relative to drag (coupled with the sail carrying ability that comes with that high stability) that gives them their higher speeds than older designs. Byond that much of that stability comes from a moderately high ballast ratio carried extremely low on the boat (typically in a bulb) so that they tend to have a very comfortable motion for a boat of their displacement and have quite high LPS's as well. (I do want to point out that the published IMS certificate LPS's do not include deck structures so that IMS racer/cruisers tend to have much higher LPS's while Grand Prix level GPS boats tend to have lower LPS's.)

    None the less, I go back to my original contention that because the IMS is a VPP based rating, it comes pretty close to predicting the actual performance of the boats that it rates and would be useful for what you are trying to accomplish. What can't be reflected in any boat's rating is that a faster boat is generally in a position to take advantage of tactical advantages that may occur.

    Respectfully,
    Jeff
     
  9. Boa-Tr
    Joined: Jan 2010
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    Boa-Tr Junior Member

    Hi Wardi,

    What happened to your research? Is there a way to reach details of it, and see what happened?
     
  10. Perm Stress
    Joined: Sep 2009
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    Perm Stress Senior Member

    Look at Yardstick databases of various countries, trace the data of boats you find interesting/representative and make your comparisons.
    As yardstick is based on actual speed on the race course, comparisons will have a sound real world base for them.
     

  11. gonzo
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    gonzo Senior Member

    I think that you first have to define what you mean by performance. Some boats are much better downwind, others point better. There are boats for light winds. Designs are perhaps more specialized. The performance cruisers of the 60's are hard to beat for overall good characteristics.
     
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