Measuring junk sailing performance

  • 26 Jun 2017 11:08
    Reply # 4917447 on 4913961
    Anonymous member (Administrator)

    Way Hay! This topic has lift off!

    Thanks for your comments everyone. Lots of good points.

    I will take up Annie's invitation and put together a proposal for a "proper" performance recording system.

    I agree with David's points about the size of the boats used for two (or more) boat comparison sailing. We used Lasers when developing the SwingWing rig. I wouldn't want to try it with anything smaller.

    It is hard to do relevant comparisons with more than two boats as getting them all sailing in the same area is difficult. We once tried formation sailing Lasers during a Hamble Regatta. It was fun but not up to Strictly Come Dancing standards. Yes it would be fun during a junket, but any results would be open to doubts about helm ability, wind shifts, etc...

    Maybe "Freebie" (and a second copy) would make a good economical test bed for different rig ideas? However, any boat is going to be less portable and accessible around the world than a data logger and a set of instructions (and an "expert" on the end of a skype call"). At least one of the data loggers in the links I provided earlier takes data from NMEA 0183 and NMEA 2000. That covers most existing boat instruments.

    As to the falling off of enthusiasm, this is certainly a problem, but on the other hand there has been a constant stream of enthusiasts creating new and exotic variations of the junk rig over the last 40+ years, but as yet we have no reliable data on any of them.

    Inevitably the enthusiasts try out their ideas on their own boats, usually on fairly limited budgets, so it seems self evident to me that if we want good data we have to do the testing on those boats. I would be happy to run the tests on boats in the UK, and possibly Europe if basic travel costs can be covered.

    Over time the JRA would build up a good library of test data, which can be studied and compared, and possibly, conclusions drawn.

    Back in the 80s I did a project for the UN FAO testing sailing fishing boats with different rigs in the bay of Bengal (Madras). They had a problem there because they had had several incidents when the local fishing boats had been unable to sail back upwind to their home port and were never seen again. We had two allegedly identical boats, and very simple instruments giving only apparent wind angle, apparent wind speed, and boat speed. We had to wait until they all settled and then quickly write down the values, and then move on to the next point of sailing. We were able to produce useful polar diagrams using nothing more than a calculator, and as I recall, these "proved" that the gaff rig was the best all round performer. The other rigs tested were Bermudan, junk, sprit, lateen, and standing lug (all of the same sail area). It took us two weeks of testing to cover all the rigs. The two boat tests produced similar but subjective results.

    I have just tried but failed to find the final results paper, but it must be out there somewhere. It would be much easier to do it now with modern instruments, data logging, and computer analysis of the data.

    It may be that AYRS have already gone down this route, or would be interested in sharing the equipment and costs. Any AYRS members out there who know about this?

  • 26 Jun 2017 11:07
    Reply # 4917446 on 4917038
    Arne Kverneland wrote:

    Edward

    .......

    Arne

    PS: Congratulations with that race from Poole to Yarmouth! Looking forward to see the result sheet,


    The result sheet should be there now. 

    3 times i have posted it along with the photos, and twice it has disappeared. 

  • 26 Jun 2017 10:39
    Reply # 4917441 on 4913961

    Bonjour

    The French magazine Voile&Voilier" organized a few years ago, regata with modified out of order Optimists with various rigging types. The sails were manufactured rapidly by a sail maker.

    The modified Optimist where given to a bench of young Optimist competitors. Each child raced on different supports. The results where interesting. Sadly, the sail maker had a very little knowledge about junk sail.

    http://www.voiles-alternatives.com/documents/comparatif-voiles-optimist.pdf

    Such experiments could be conducted in a similar way between various junk sails and junk wings;  at a very low cost.

    A sailing magazine could be involved to promote the results.

    Eric


  • 26 Jun 2017 08:56
    Reply # 4917411 on 4913961

    It's Annie's final paragraph that makes the most telling point, I think. The phrase "herding cats" is probably the one that comes most readily to mind, to describe a project to build and race a fleet of JR dinghies. 

    However, just supposing it were to go ahead (and yes, it would be a fun thing to do) then 8ft is too small. It's harder to make one of the more complex JR variants at this size than, say, at a size to suit a 12ft or 16ft dinghy. At any size between 8ft and 16ft, crew weight and skill level make a huge difference, so we're certainly not talking about rigorous testing, we're talking about having a bit of educational fun.

    For rigorous testing, I would suggest that an old racing class such as the Sonata would be the better platform. Take a cheap one (one for £2000 on ApolloDuck at the moment), put in at least three sets of mast partners and steps (well forward for low AR rigs, well aft for split- and aero- junks, somewhere between for "conventional" junk rigs), and add Alan's instrumentation. Then you have a boat that can take part in club racing, or go off on its own, logging data. But why would anyone want to do this? Only, I suggest, as a step on the learning curve towards putting together a serious, large race boat for something like the OSTAR. Why else do we need to know whether one JR is 1% "better" than another? 

    I certainly don't. I want an efficient rig, but I don't measure efficiency in terms of speed to windward any more (though I used to). I measure it in terms of "miles sailed per £ or $ or €" or "miles sailed per unit of crew effort or hassle". I suspect that for many of us, an instrument that will run a cost/benefit analysis on the various forms of JR is what we need.

  • 26 Jun 2017 08:10
    Reply # 4917394 on 4917113
    Chairman JRA wrote:

    On a personal note, I'm not entirely sure that having all the facts at our fingertips. presented as rationally and clearly as possible and backed up with all the science in the world will make any difference.  People will still prefer bermudian rig ("My mind's made up - don't confuse me with facts"); people will prefer the appearance of one junk rig over another; people will put simplicity above complexity; people will want to try new ideas; people will choose one style of rig over another - because they can fit their accommodation around it - and junkies will remain unconvinced that rig B is better than their rig A because that's how people are.

    I think that Annie has made a very valid point here. Regardless of what we may do to try and promote the junk rig and demonstrate the superiority of the junk rig over other rigs, it will probably only be for the benefit and edification of us, the already converted. Just as there are people who will only live in a conventional house with umpteen bedrooms and bathrooms, and those who will live in a tiny house, and those who are quite happy to live in a house bus or house truck, the same applies to people's choice of boat and rig. The vast majority of the sailing world is going to go for the conventional, while a few of us, (enlightened People ??) are prepared to try something different and can recognise the benefits of the unconventional rig such as a junk.

    While I am very keen to try and compare rigs with 'Shoestring', I have no other real interest in trying to prove that my junk rig is any better than any other rig. I am happy to just get out and enjoy what I have.


  • 26 Jun 2017 00:38
    Reply # 4917201 on 4913961

    I think the idea of a small fleet of identical dinghies, raced during rallies, seems the most achievable project, and it would also be a fun thing to do, which always motivates people.  By sailing triangular courses, swapping skippers regularly, sailing in a variety of conditions etc, some patterns would emerge.  It could also be an ongoing conversation, conducted every summer when the junks gather, and duly written up for the JRA magazine, rather than something that tried to establish a determined outcome (There are bound to be dissenting opinions, but that will only add to the overall interest).  There could even be one dinghy rigged with a bermudian sail.  I think, however, that any information gleaned would be mostly for the benefit and enjoyment of JRA members, though an article in a magazine like PBO or Yachting Monthly might inspire others. 

    Conducting more scientifically rigorous testing, with instrumentation, would be an interesting project, but would involve a lot more expense, and require a team of competent participants, which might be hard to justify financially, and even harder to administer.

    Where to base the fleet of dinghies is an interesting question, both in terms of building them and where to store them between outings.  There could, of course, be more than one fleet.  NZ seems one likely place, since there is such an active community there, and maybe Pete Hill would help build them, with some volunteers.  The UK would be the other place that springs to mind.  In the end it would come down to willing hands.

  • 25 Jun 2017 22:48
    Reply # 4917113 on 4913961
    Speaking as Chair of this august Association, I am all for this.  Indeed we debated it at the AGM and there have been subsequent discussions about the matter in a working party of Pete Hill (whose idea it was), Rob Prince and Marcus Raimon.  The fact that Pete has sailed off into the Pacific has brought something of an hiatus to proceedings.  I am not involved in this group, nor do I want to be, having more than enough to do as it is, but thought I'd better mention that the matter is under debate.

    As I gather, the overall conclusion was that probably the most effective way of getting people on board and involved is to choose a dinghy of around 8ft, which would make a fine tender and design a 'standard' junk rig for it, to be chosen by the working party.  The idea would be that people who wished to experiment would then fit a variation of their choice and that the dinghies could sail and race together at junkets.  This is far from scientific, but on the other hand, gut feelings have been proven often to be just as sensitive as the best of instruments.  Ideally, rigs could be swopped from one dinghy to another, as, of course, could helmsmen.  I believe that with a reasonable number of people actively involved, a consensus would emerge.  I see no reason why the JRA shouldn't commission a design for said dinghy and supply funds for say half a dozen to be built, but this is something that must first be put to the Committee and debated fully. 

    I'm not dismissing Alan's notion that this should be done 'properly,  However we need

    1. boats to test
    2. sailors to sail them
    3. volunteers to fit the instruments
    4. a regular schedule set up and adhered to, so that the concept doesn't just fade out

    If a proper, fully thought-out proposal were made to the Committee, I can promise it would be considered.  However, we have a dire record of enthusiastic ideas being thrown out, picked up and then quietly dropped.  I am very happy to see our funds used usefully: I'm not prepared to vote for them being spent on something that is not properly prepared and unlikely to be completed.

    On a personal note, I'm not entirely sure that having all the facts at our fingertips. presented as rationally and clearly as possible and backed up with all the science in the world will make any difference.  People will still prefer bermudian rig ("My mind's made up - don't confuse me with facts"); people will prefer the appearance of one junk rig over another; people will put simplicity above complexity; people will want to try new ideas; people will choose one style of rig over another - because they can fit their accommodation around it - and junkies will remain unconvinced that rig B is better than their rig A because that's how people are.

  • 25 Jun 2017 21:33
    Reply # 4917038 on 4913961
    Anonymous member (Administrator)

    Edward,
    I can see your point with respect to attending a whole series of club races  -  it sounds more like work than fun.

    However, there might still be race data from a few races available (last year?).

    My idea is to disregard handicap and corrected times. What I am after are the elapsed times of the other Splinters in the club races. These can be averaged and then be compared with Amiina’s time. One could even find the average sailed time over several races (same track?).

    The result could tell how Amiina fares against the other Splinters, in percent.

    Arne

    PS: Congratulations with that race from Poole to Yarmouth! Looking forward to see the result sheet,


    Last modified: 26 Jun 2017 09:48 | Anonymous member (Administrator)
  • 25 Jun 2017 20:53
    Reply # 4916987 on 4914737
    Arne Kverneland wrote:

    Alan,
    you know, this is not easy to arrange. It is next to impossible to arrange a line-up of three or five identical boats with all sorts of junk rigs, and then compare them in a series of races. Moreover, reporting instrument readings only are of little interest as the conditions vary so much.

    Now I got an idea for a second-best, but hopefully realistic method:
    ............

    Edward Hooper should have plenty of such statistic material available after having raced Amiina. I am sure there are other classes too, like the Hunter 19 Europa and Contessa 26, which are being raced each week. If one could join them, a really realistic comparison could be made.

    "................

    Arne


    Hi Arne, 

    I wish i had worthwhile and usable statistics.  I am very sorry to disappoint you.  I have been such an irregular and un- enthusiastic 'round the buoy' racer for several reasons.  Mainly family pulls have meant i miss a lot of the races; then the very Bermuda biased handicap system keeps changing.

    Now our clubs all go for VPRS, and boats using Spinnakers get a lower TCF than boats not using one.  So i could not take it seriously.  I do however enjoy the longer races, but they come up too rarely.  Even among the Van der Stadt Splinters, it turns out they are not all alike.  Amiina has a skeg, and normal rudder; Whisper and the other Poole Splinters don't have a skeg, and have a balanced spade rudder, so they tack much faster, but are not so directionally stable.

    I have just put in the Racing forum a short report re a recent race to Yarmouth, for what it is worth.

    You can also see some photos, and the results sheet on my photo album.

  • 25 Jun 2017 19:21
    Reply # 4916861 on 4913961
    Anonymous member (Administrator)

    Thanks Jonathan, that's encouraging. Just to give a feel for costs, here is an article about a reasonably high end system that costs just under $3000. I'm not saying this is the best or only system, just that it is one that is available and appears to be useable on something as small as a Moth.

    http://www.sailingworld.com/gear/mining-numbers

    And here is another one! This one is ChF 1990 (that's Swiss Francs) for the basic box.

    http://www.anemomind.com/overview/

    Last modified: 25 Jun 2017 20:32 | Anonymous member (Administrator)
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software