International 505 Class Yacht Racing Association
Notice of Members' Ballot
At the 2000 AGM in Durban, the meeting approved the following proposal made by the International Executive Committee, with over sixty votes in favour and none against. The proposal therefore now has to go to a ballot.
Proposal
That Rule 8.4.2 to be deleted and replaced with:8.4.2 The following dimensions shall not be exceeded:
� Leech length
� Foot median (head point to mid foot point)
� Foot length
� Half width6000mm
7096mm
4500mm
4500mmThat Rule 8.4.3 (the 75% rule) be deleted
That Rule 7.2.4 to be deleted and replaced with:7.2.4 The highest point of entry onto the block, sheave or fairlead for the spinnaker halyard shall not be more than 5955mm and not be less than 5054mm above the deck band. No rigidly fixed point for attachment of the block, sheave or fairlead may extend more than 35mm from the surface of the mast.
That the effective date of the change will be 1 October 2001.
C G Thorne
International Secretary
Summary
These changes permit an increase the maximum permitted height of the spinnaker by 1 metre and allow the highest point of entry for the spinnaker halyard on the mast to be 850 millimetres higher.
Reasons for Change:
Spinnakers made to the maximum dimensions originally designed by John Westell in 1953 have not been used for many years. It was found that three sail reaching with the crew on the trapeze was fun, and that the fastest spinnakers on a reach had to be considerably smaller than the maximum. This was because of the stipulation that the width of the spinnaker at its half height had to be at least 85% of the maximum width (since the beginning of 2000 75% of the foot width). In order to keep the sail away from the back of the mainsail when close reaching a narrower sail had to be made. Spurred by developments in other classes a number of leading 505 sailors started experimenting with taller spinnakers. Taller, narrower spinnakers could retain the advantages of a good reaching shape, but give us back the area lost from John Westell's original design. These experiments first came to the notice of a wider audience at the 1997 Worlds in Gilleleje, when Krister Bergstrom advised the IEC of experiments he had been undertaking. These trials were then also taken up by a group of Danish sailors. At the Quiberon Worlds in 1999 it was agreed to introduce an experimental rule based on the experience of the early trials. The experiments had included increasing the height by as much as 1.5 metres, and also lowering the pole attachment to gooseneck level. The optimum was found to be to just slightly lower the pole, to raise the halyard take off by 850mm and to increase the spinnaker luff length by a metre. Spinnakers larger than this put too much strain on the mast. Taking the pole much lower obscured leeward visibility too much. Increasing the spinnaker height by less than 1m did not give enough performance gain to make change worthwhile. Accordingly the IEC approved an experimental rule based on the proposals now before you and encouraged National Associations to allow experimentation under racing conditions between September 1999 and November 2000.
Last year the Australian Association adopted the experimental rule enthusiastically and all who tried the new spinnaker have reported that it significantly improves the boat. The Scandinavians have continued to use the new spinnaker and also there has been more limited experimentation reported in the US, UK, France and Italy. Extensive reports of these trials can be viewed on the International Association Web Site, www.Int505.org.
As a result of the trials the IEC has decided to support the introduction of the change on a permanent basis. As a performance class the 505 has always been at the forefront of developments in dinghy racing. Modern materials, hardware and sail making techniques are far ahead of where they were in the 1950's and 60's and by adopting this change we will be giving ourselves the opportunity to make the most of the superior technology now available.
Some Q&A's
What will the change cost?
Initially anyone wanting to take advantage of the enhanced performance will need to buy a new spinnaker, or adapt an old one. Most people sailing competitively will be buying new spinnakers on a regular basis so the extra cost over the next couple of seasons need not be significant. Since most of the cost of the sail is in the labour, the cost of the additional material will be also insignificant. Existing masts can be easily adapted. The existing sheave can be removed and a simple block fixed with an eye to the outside of the mast at the new height. The halyard, which will need lengthening by just over a metre, is just lead out through the existing hole and up the outside of the mast. There is no need to move the existing pole attachment on the mast - the outboard end of the pole can be carried lower.
Will the mast break?
Experiments have taken place using the three most common sections in use today, the Proctor D, Superspar M7 and Goldspar. They have taken place in winds of up to 30 knots on flat water and at sea. The masts do flex more, but no failures have yet occurred. The Scandinavians have mainly sailed with the American style low hounds rig. The UK style high hounds rig will give more support to the top section.
I sail with a light and/or female crew. They struggle with the existing spinnaker. Will we be unable to compete if everyone else is using bigger spinnakers?
The biggest spinnakers under the existing rule are heavier to use than the smaller sails favoured by lighter crews. However, this is because they produce as much heeling moment as forward drive. If you do not have the weight to counter that heeling moment you will find the sheet loads uncomfortable. However, the rule is designed to allow a taller and narrower sail, and the abolition of the half height rule will allow much flatter sails to be used. These will be easier to drive and develop less heeling moment. Anyone who has sailed on a boat with a large asymmetric spinnaker will know that the sheet loads are lower than for smaller symmetrical sails.
In Australia a number of female crews have tried the new sail. Although some have reported the boat handling more difficult, (this is not exclusively a female problem!) none has felt the sail too powerful to handle
Is the boat harder to sail?
As with any change of equipment, handling the new sail will take getting used to for many crews and some may have to adapt their techniques. However, some have reported that gybing is easier because of the higher speed. In strong winds and big seas it has been found that current tendency for the boat to bury itself in the back of the wave in front is much less as the bow lifts more and the boat just goes straight over the top. This reduces the risk to the mast and makes sailing off wind easier and more enjoyable
Will the sail be harder to pull up and down?
Just as at present, friction in the spinnaker chute/launcher will depend upon the bulk of the sail. Any sail built on maximum width (very few are) will be harder to handle in the chute than a narrower one. A taller sail will not bulk up in the chute any more than a shorter on of the same width if a single patch system is used. A metre extra height on the sail only needs an extra half metre of the folded sail to come back into the boat. Stowing the sail has not been a problem with any of the wide variety of boats used in the trials.
QUOTES
"IN THIRTY NINE YEARS OF SAILING 505'S I HAVE NEVER BEEN SO FAST. That's a big statement after all the years I've been sailing, but I kid you not, it was just unbelievable! In one gust we actually left the crest of a wave, became airborne and "flew" to the next wave….. the remarkable thing is, it lifts the bow and actually makes the boat easier to steer in the big seas and big winds." - Pip Pearson
"…… the boat is also a lot easier to sail on the reaches - particularly in strong gusty conditions. The boat doesn't want to round up every time you get slightly 'out of balance' or you didn't see the gust coming. The rudder almost never cavitates. When a gust hits, the nose of the boat lifts up, the boat bears away and takes off. The driver really doesn't even have to lean any harder or ease the main. Whatever the technical reasons, the boat is a lot easier to steer and is very, very quick. It feels better, looks better and is a lot more fun." - Michael Quirk
"I used the standard size spinnaker and got around the course very comfortably. But having used the bigger spinnaker in fresh conditions, today was quite boring. I was envious watching the boats with big kites screaming down the reaches and runs. I don't think that having to develop better crew work and boat handling skills is a negative thing for the class, keeping in mind that the boat is not any physically harder to sail." - Dave Porter
"The spinnaker I got is taller and flatter, therefore I noticed a great increase in performance in close reaches while on the dead run is not so hot (mind you it is also possible I got used to the incredible performance on the reaches)..Such a shape will enhance gybing contests (it is more similar to a jennaker in the use). The higher aspect seems to give cleaner flow over the spinnaker. . Because it is flatter it does not empty as often, (and is) more forgiving. Overall it seems as easy as the old one to carry. My crew and I are both 75kg - Marco Giraldi