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IOR v todays boats

Printed From: Yachts and Yachting Online
Category: Keelboat classes
Forum Name: Keelboat news and development
Forum Discription: All the latest developments for yachts
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=12125
Printed Date: 15 Dec 17 at 12:54am
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Topic: IOR v todays boats
Posted By: gordon1277
Subject: IOR v todays boats
Date Posted: 13 Aug 15 at 11:30am
I raced yachts back in the 80's all seemed to be tonners(1/2, 3/4 and 1 ton)
How much quicker is a 40 footer now compared with then say in a 60 minute race or round the island?
I know they have improved in many ways and without all the weight in the boat and not in the keel they must be so much stiffer and nicer to sail.

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Gordon
Lossc



Replies:
Posted By: laser193713
Date Posted: 13 Aug 15 at 11:57am
Round the island now takes around 5 hours, rather than 7 ish for a 40 footer... Good enough?

Edit. Look at some IRC numbers for boats at cowes week. Rebellion (Carkeek 40) is in Class 0. IRC rating 1.267. There is an Elan 40 from 2004 in Class 4 at 1.025 and the rating list for the NZ 1 ton Revisited class begins at 0.926 for what I can only presume is a non updated boat, some of them are much faster according to IRC which means they must have been optimised and modernised.

Scale 0.926 up to get a percentage faster for the new boats and you come to about 36.8% faster.  Sort of ties in to the 5 hours/7 hours above...


Posted By: gordon1277
Date Posted: 13 Aug 15 at 2:02pm
Thanks Laser
That is a huge improvment, shows how much the old rules were distorting and slowing boats down.
It would have meant a lot more sleep in my own bed at home rather than on the rail as was the stupid cold fashion at the time.
I gave up yacht racing after a season of hard racing and bought a 505 best thing I ever did.

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Gordon
Lossc


Posted By: laser193713
Date Posted: 13 Aug 15 at 2:22pm
They are much wetter boats these days though, and much less comfortable. Remember, the physics of sailing haven't changed, these boats just don't carry around a library of almanacs and beautiful teak galleys. Many of the 1 tonners had all of this. The materials available these days maybe account for 5% of the performance improvement. If you took a mould of an old IOR special and made it in new materials with carbon masts and sails etc that is all you would gain. What the materials do allow is much wider boats, much lighter boats and much less drag from foils and spars and rigging. The biggest differences are in light wind performance and downwind performance. This is why so many people thing that modern boats are dog slow upwind. Just because the beats take 20 minutes and the runs are taking 5 minutes for some of the classes these days doesn't mean they are slow upwind, it just shows how fast we can get boats going downwind these days. 


Posted By: gordon1277
Date Posted: 13 Aug 15 at 4:39pm
Hi Laser
The x yachts one tonner I sailed on had no teak interior, it was stripped out interior pipe cots etc also they had very low freeboard and were also wet. It was the Jade and Panda year when we had 11 one tonners for 9 spots in the one ton cup so very competitive.
Cheers


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Gordon
Lossc


Posted By: blueboy
Date Posted: 22 Aug 15 at 11:52am
Originally posted by laser193713

(Carkeek 40) is in Class 0. IRC rating 1.267. There is an Elan 40 from 2004 in Class 4 at 1.025 and the rating list for the NZ 1 ton Revisited class begins at 0.926 for what I can only presume is a non updated boat, some of them are much faster according to IRC which means they must have been optimised and modernised.


What it really means is the Carkeek 40 is a big dayboat with zero possible after-life as a cruiser and which you'd be bonkers to race offshore.

The NZ 1 ton class allows boats from different IOR eras e.g. IOR 27.5 and 30.5 foot raters. That may explain some of the differences in IRC ratings. Remember also these boats have benefit of shed-loads of age allowance so comparing them to a modern IRC hull and design is somewhat misleading.

I'm not saying that a modern IRC or ORC optimised 40 footer isn't significantly quicker than a late period IOR one tonner but the difference isn't as large as you are suggesting.





Posted By: Five Star Sailor
Date Posted: 06 Feb 17 at 2:43pm
I recently bought a Corel Farr 45 20+ years old for my sailing school to race in the UK and in the Med including the Rolex middle sea race where we can sail in IRC and/or ORC, it was not built to any rule, and sailed for many years in one design mode.
I'm advised that these boats were one of the first designs since the decline of IOR, It is a wonderful boat to sail that surfs and planes readily I am surprised with how it is treated on handicap by IRC! it rates at about  IRC 2016 1.215. which seems high, difficult to sail to. whereas in  ORC2017 GPH 514,5 seems very sailable to! The boat is still in one design mode.
My question is this, What can I do to improve my speed to handicap ratio without spending lots of money? as a sailing school we don't have deep pockets.
regards, hoping for some helpful replies, Regards, John



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X john



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