New Posts New Posts RSS Feed: Measurement Based Handicapping
  FAQ FAQ  Forum Search   Register Register  Login Login

Measurement Based Handicapping

 Post Reply Post Reply Page  <1 567
Author
Rupert View Drop Down
Really should get out more
Really should get out more


Joined: 11 Aug 04
Location: Whitefriars sc
Online Status: Offline
Posts: 8956
Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Topic: Measurement Based Handicapping
    Posted: 07 May 09 at 2:20pm
Surely the effects of crew weight and height are going to change not only per boat type, but for wind strength, variability and the point of sailing one is on. I can't see how anything with that many variables is ever going to get beyond being effectively guess work.
Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
Back to Top
Isis View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 01 Sep 05
Online Status: Offline
Posts: 2753
Post Options Post Options   Quote Isis Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 09 at 2:43pm
Originally posted by Bas Edmonds

Havent we forgotten the righting moment acheived by the crew? Should we not be looking at weighing crews before every event and factoring that into the equation?


Nope, crew weight and height is factored in. For the time being ive taken the middle of the suggested weight range for each class and left height as a constant.
Obviously how this would actualy be imlemented if the system was ever used is a pretty big sticking point and one of the 2 main problems I can see if a similar system was ever used.

(The other big problem would be how development and even some of the more open one design classes are handled... What would happen if people started optimising towards the rule rather than towards winning class events?)

Hi Isis,

Any more details on how your system works, what the formula is etc? I'm sure I'm not the only one that is interested.


Its a VPP based rule as opposed to a formula - Pretty similar in principle to the IMS (or ORCi as its known know) rule from the keelboat world.

Edit: VPP = Velocity Prediction Program

The program takes 20 values describing the hull shape (and a few more describing rig, foils, and crew) and creates a representative model of the boat - It then balances the aerodynamic and hydrodynamic forces for a range of wind speeds and angles and the resulting speeds give you a pretty good view of the overall performance. The handicap then comes from these performance figures based on the course type and wind speed you choose.

Originally posted by Daniel Holman

Isis, Did you find much use for the stuff I sent over last year?

Good to hear you're happy with the outcome, lets hope it gets some good loving from the examiner!

That had parameters involving the RM of the crew, assuming a crew weight / height pertaining to each boat. I also sent them to Bas in january post BM but this went unacknowledged.


Dan, thanks again for the stuff you sent me - It was definantly interesting to have a look through but I didnt actualy use any of it in the end having gone down a  different route to yours. If you want to have a chat about what I come up with then send me another email.



Edited by Isis
Back to Top
Daniel Holman View Drop Down
Really should get out more
Really should get out more


Joined: 17 Nov 08
Online Status: Offline
Posts: 997
Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 14 May 09 at 2:21pm
Oh yeah, you're possibly sick of the project now, well into post dissertation drunken abandon but how much info do you need to run some numbers on a boat?
I'd be interested to get an idea on mine, and have every measurement imaginable.
Back to Top
 Post Reply Post Reply Page  <1 567

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy