Merlin PYs...

General chat about boats
Nigel
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Re: Merlin PYs...

Post by Nigel » Mon Jun 01, 2015 4:26 pm

:lol:

.....and walnut shells.

this forum is a friendly one but I think PYs are often at the root of the most contentious discussions at a sailing club. I always walk away as soon as they are raised as logic is usually the first casualty.

My view (for what it is worth) is that it is impossible to have right answers with PYs. The most we can hope for is that in different conditions, they are wrong in different directions so it all evens out eventually but I do think that this is also their greatest strength in as much as when they work in one's favour, the result gives people the encouragement to keep persevering through the days that they don't - not only at the front of the fleet but in the middle and at the back where individuals are having their own private races with the boats around them. The inadequacies of the system allows those of us at the middle and back of the fleet to deceive ourselves a little but I do not think that is such a bad thing. Disenchantment will just lead to less boats on the water.

As long as I come off the water with a smile on my face, I am a winner (just as well really)

Rupert
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Re: Merlin PYs...

Post by Rupert » Mon Jun 01, 2015 4:35 pm

You didn't, Nigel... Mentioning walnut shells... That's like walking into a pyrophobia meeting and shouting "Fire!".
Rupert

Nigel
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Re: Merlin PYs...

Post by Nigel » Mon Jun 01, 2015 4:43 pm

................such happy memories.... :lol:

Nigel
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Re: Merlin PYs...

Post by Nigel » Mon Jun 01, 2015 4:52 pm

not that I make a habit of this but....

I did walk into a crowded Spanish restaurant a few years ago, look up at the imposing portrait of Christopher Columbus and remark "ooh look! Sir Francis Drake"

JimC
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Re: Merlin PYs...

Post by JimC » Mon Jun 01, 2015 6:50 pm

Rupert wrote:The OK class has just bucked the trend, but they do have plenty of weight to play with!
I fear that's simply a case of sailor ability beats boat speed every time.

I haven't managed to work out a way to do a correlation with the data, but it seems to me that every class that permits at least two and maybe only one of the trio of laminate sailcloth, carbon spars and epoxy foam sandwich hulls has seen a big drop in yardstick against the general average, and classes that have not changed at all have tended to rise.

With Solos at my club, which is moderate size and inland I seem to have a measurable difference: certainly the delta of the Solo fleet against the Laser fleet has changed greatly since foam sandwich boats came in. Even our most determined wood boat owner and builder has given up and bought a plastic one and seen a significant performance difference. I'm at a loss to explain how come there's such a differential on a moderate size reservoir but have little doubt that it exists.

Pat
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Re: Merlin PYs...

Post by Pat » Mon Jun 01, 2015 7:01 pm

Michael - take consolation that you are perfectly placed to sail in the Bosham classic revival in September and your old wooden boat will then be much admired (as long as you park it on the green) and will fit in very well.
(Half Cut and What a Lark Removals Ltd)

davidh
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Re: Merlin PYs...

Post by davidh » Mon Jun 01, 2015 8:01 pm

Jim C,

some of the data that I've seen came from Inland locations, but it was quite clear in the discernible speed differential. Like you, I'm not clear as to the root cause for the difference, but I'm clear that it is there.

Interestingly, over the last couple of weeks, I've had something of a 'eureka' moment with regard to my thinking regarding PYs - and in particular, the relationship between higher performance and PY. The core of the PY system is linear, but doesn't always seem to behave that way. I'm not all the way there yet, the ideas are still a bit of a jumble, but I will make sense of them soon!

D
David H

Rupert
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Re: Merlin PYs...

Post by Rupert » Mon Jun 01, 2015 8:17 pm

My basic thought with the system is shown by the Merlin and one designs that develop stayed still, which means the whole system was getting faster, somehow. Since the changes to the system a few years ago, with actual times coming in and speedy changes, the classes which have freeish rules compared to say the Laser, have seen handicaps plummet, which suggests the system is now still and the boats moving.

What this doesn't explain is why frp boats with Mylar sails, even with tin masts, are going faster than really nice, up together wooden boats. The hull shapes are virtually identical, they are both down to weight, both stiff enough, especially when looking at flat water, yet there is a difference.
Rupert

JimC
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Re: Merlin PYs...

Post by JimC » Mon Jun 01, 2015 8:41 pm

Rupert wrote:which suggests the system is now still and the boats moving.
The average PY across a good sample of popular boats has stayed near enough constant for 50 years, but I think the actual intrinsic speed of all boats has improved with advances in things like rope, fittings, technique, even standard of finish. But whereas up until the new materials revolution static classes stayed pretty static - Wayfarer PY was unchanged over 40 years or something - in recent years everything has been changing. I think we missed a trick and probably, as happened with terylene sails against cotton, new numbers should have been issued for every class that had a major materials update. The trouble is that change is only visible with hindsight.

chris
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Re: Merlin PYs...

Post by chris » Tue Jun 02, 2015 9:31 am

At a MR (Vintage) meeting at Cookham a few years ago this subject came up. This was separate from the handicaps used in the deMay. A small sub committee promised to look into it, the main issue being that of linking age numbers to the current PY. Nothing happened so I prompted and was given a reply that the base would be fixed at 1000 from now on. I'm not sure if this ever got as far as being put on the merlin website and I think it did make a brief appearance but when they redid their website it certainly was the old system that reappeared. So basically nothing actually happened in that respect. But even at this stage as has been said MROA numbers are suggestions and the bottom line is that it is the clubs who have the last word (even with the RYA list who do say they want the clubs to modify their numbers).

Our club is a small inland lake and we have been sending in race results to the RYA and when there is enough data the RYA will give us 'official' numbers to use for our boats on our water. These will undoubtedly be different to those give to, say, a sea club.


This RYA system may sound promising but I am concerned that it will include a greater percentage of crewskill than is desirable. If a club wants to run on personal handicaps that's OK but we don't. There are eight classes of boats in our club that are lone examples. So the difference between such a one being sailed brilliantly or poorly can't really be evened out in the data presented to the RYA .

Don't forget that all the data sent in is from mixed fleet racing not class racing, I guess many club that have mixed class handicap racing may only have one or two examples of any merlins and the may be 40-50 years apart but will probably be entered just as Merlins.

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