The UK Dart 15 Association

One design Sprint 15

Dart 15 Chat
Erling
Rear Admiral
Rear Admiral
Posts: 303
Joined: Mon Dec 18, 2006 9:59 pm

Re: One design Sprint 15

Post by Erling »

After being in finance for 30 years I know you can do anything with figures and George has proved it by useing Liam's results when he only started sailing in 2010 against others that had been sailing for years and then claming its the boat built in 2004 and not the fact that he does over 100 class races a year. We have a table at Shanklin for your average points over the year and if you look at his improvement it is as you would expect from someone that sails about 200 days a year: in boat 554 2010 = average 5.392 2011 = 4.718 2012 = 3.299 2013 = 2.911 then he changed his boat to 1957 2014 = 2.759 2015 = 2.49 and in 2016 = 2.18.
The results you see are what you would expect and nothing to do with George's Data Analysis, if you want to get true data use someone that has been saiing the same time as all the others.
paulgrattage
Leading Rate
Leading Rate
Posts: 21
Joined: Sun Nov 20, 2011 9:02 pm

Re: One design Sprint 15

Post by paulgrattage »

You need to look further than overall results to see the impact of the new boats. Look at the results of the last nationals before the new boats at Brightlingsea . https://www.sprint15.com/events/EMS/event.php?id=89 The winner has 17 points. Compare to the next year at Thorpe bay the winner has 4 points and the event is over before the last day. Same story next year at Pentewan
User avatar
Bob Carter
Admiral of the Fleet
Admiral of the Fleet
Posts: 1687
Joined: Fri Dec 15, 2006 8:52 pm

Re: One design Sprint 15

Post by Bob Carter »

DavidGroom wrote: I also wonder if the author(s) of the latest article could identify themself/themselves and clarify exactly what inaccuracies and omissions they refer to in the "unauthorised" memo.
Here are some:

Background on Boat Weight:
Throughout the 40-year history of The Class, there has never been a specified weight for the boat. Early publicity material cited a weight of 104kg. that is still adopted by the SCHRS handicapping system. The boat is built to a specification that allows tolerances for quality of hand lay-up in the building of the fibreglass hulls, equipment at the date of manufacture, raw material supply and production deadlines. The lack of a specified weight was a conscious decision by the original manufacturers from the start of production in recognition of the issues that could emanate as a result of specifying a weight. Other classes adopt the same approach for good reason, notably Laser and the Dart 18, both of which are also constructed from fibreglass.
Neither the manufacturers of the Laser nor the Dart 18 have removed heavy components (weighing approx. 5 Kg) from these boats. New boats remain of a similar weight to what they have been throughout the life of the classes. The same (optimistic) sales literature which cited the 104Kg for the Spark cited 130Kg for the Dart 18 but is generally acknowledged that the actual sailing weight for the Dart 18 is 140Kg.
The Committee’s Proposal – why now?
The Committee’s proposal seeks to address an issue that has always existed but is predominantly aimed at post 2014 boats. As noted above, pre 2014 boats could vary in weight by as much as 17kg. Adopting a minimum weight rule at this time is not a logical approach. It makes no sense and does not logically address historical anomalies of weight across the fleet.
Much of the weight variation of pre 2014 boats is a result of repairs and water absorption over the life of these (old) boats. The water absorption can be severe if the owner(s) have not regularly drained the hulls and kept them ventilated. We are only concerned with the new boat weight - there is no intention to correct for weight gain over the life of the boat(s). This is effectively the same as the Laser & Dart 18 Classes.
If weight was ever an issue, it should have been addressed many years ago.
It was in 1988 when hulls without cocktail cabinets were required to carry a 3Kg corrector weight per hull (see Class Struggle by Nick Dewhirst).
And, if the weight of post 2014 boats is an issue, it should have been addressed when they were first built over four years ago. It was controlled by rule 10y which states “ Allow front beam using the larger Dart 18 section front beam together with strengthened beam sockets in the hulls and removal of the rigid inner mouldings of the cocktail cabinets replaced by mesh bags below the hatch covers provided that the overall weight of the boat is unchanged.“. Post 2014 boats do not comply with this rule.
DavidGroom
Lieutenant Commander
Lieutenant Commander
Posts: 163
Joined: Mon Jun 23, 2014 7:42 pm

Re: One design Sprint 15

Post by DavidGroom »

Bob. I take it from your response you are the or one of the authors but I am still not clear who else agrees with you points and whether they are Committee sanctioned. I stress it does not matter as you have every right to disagree with us but context is always important. See you over the weekend (trophy is already packed in Van) slim hope of winning it this year so nicely cleaned for new holder
David Groom

For cat sailors life has two certainties d@@@h and racing a Sprint 15
User avatar
Bob Carter
Admiral of the Fleet
Admiral of the Fleet
Posts: 1687
Joined: Fri Dec 15, 2006 8:52 pm

Re: One design Sprint 15

Post by Bob Carter »

Hi David,
Yes correct. Chairman, Chris Tillyer, approved it before posting.
Good to hear that the trophy is clean. See you at the weekend.
Regards
Bob
User avatar
Bob Carter
Admiral of the Fleet
Admiral of the Fleet
Posts: 1687
Joined: Fri Dec 15, 2006 8:52 pm

Re: One design Sprint 15

Post by Bob Carter »

A few more:
Do race results prove that the new boats have an unfair advantage because of their weight?
The short answer to that question is ‘No’. A results based analysis was undertaken.
The answer has to be ‘Yes’. New boats have a weight advantage that is bigger than any class legal new boats built prior to 2014.
This compiled the results of the five helms who have new post 2014 boats. A comparison between their average points tally in their new boat and the corresponding tally for their old pre 2014 boat was produced for all the events at which they competed between 2011 and 2017.
The analysis is confounded by many factors blurring the results. The performance of each sailor is assumed to be constant over the time period concerned. Older sailors tend to become less good as their age catches up with them. Younger sailors get better with practice.
This showed that:
• three of the five helms have improved their results which should be expected with a new boat. It’s one of the principal reasons why sailors in any class buy one.
It is informative to look for the step changes in performance. The difference in George Love’s results when he got the new boat was staggering. It happened overnight and was very apparent.
• two of the five helms have posted worse results in their new boat.
Possibly an age / illness effect?

A table is included with this communication to illustrate the analysis with notes, interpretation and conclusions.
In addition, a comparison was also made with another sailor, Liam Thom, who has posted much improved results after changing his boat to a newer pre 2014 boat from an old ‘Spark’. The newer boat with a new sail showed a significant and expected improvement in his results.
True but you are also comparing Liam’s performance as a relative novice to now. He must be one of the most enthusiastic sailors whom sails many days/week and he has undoubtedly become a very much better sailor as well as changing boats.
User avatar
Liam
Site Admin
Site Admin
Posts: 977
Joined: Sat Aug 01, 2009 7:23 am
Location: Isle of Wight
Contact:

Re: One design Sprint 15

Post by Liam »

I don't like all this dissing of the Jagular. :D
554.jpg
554.jpg (27.46 KiB) Viewed 31957 times
2034 - No Quarter, 1957 - Dreadnought, 1709 - Biscuit
Shanklin Sailing Club
Holder of OTT Shield
9th most improved at 2018 Nationals
User avatar
Bob Carter
Admiral of the Fleet
Admiral of the Fleet
Posts: 1687
Joined: Fri Dec 15, 2006 8:52 pm

Re: One design Sprint 15

Post by Bob Carter »

Just a quick note to say that the AGM on Saturday voted not to adopt a minimum weight rule or to add weights to the new boats.
Harmony in the fleet and the preservation of a supply of new boats turned out to be bigger issues than the weight advantage of the new boats.
Regards
Bob
dave42w
Sub Lieutenant
Sub Lieutenant
Posts: 108
Joined: Sun Aug 28, 2016 10:27 pm

Re: One design Sprint 15

Post by dave42w »

I asked Brian for a one off carbon fibre Sprint 15 but he didn't seem very enthusiastic about building it for me ;-)
Crazysurf
Warrant Officer (Class Two)
Warrant Officer (Class Two)
Posts: 61
Joined: Mon Dec 26, 2011 8:24 pm

Re: One design Sprint 15

Post by Crazysurf »

:D
dave42w wrote:I asked Brian for a one off carbon fibre Sprint 15 but he didn't seem very enthusiastic about building it for me ;-)
Post Reply