i550class.org

Hi Chad,

CR 5.9.2 says "A spinnaker shall only be sheeted at a single point and shall not include a yardarm." What does this mean? Common nautical usage has a yard(arm) as a spar crossing a mast, and typically at the head of a square sail. I have a suspicion that this class rule is intended to prohibit whisker and spinnaker poles. Is that the intent? If not, what?

If prohibiting whisker or spinnaker poles isn't the intent, I might be inclined to consider a whisker pole for those (rare?) occasions when wing-on-wing sailing might be beneficial. This question is timely because I am having a mast built and would want to ask the builder if he recommended extra laminate in way of the whisker pole ring. The only negative to a whisker pole is it would probably need to be longer than J to be useful, and PHRF-NS penalises whisker poles longer than J.

The RRS limit whisker pole use to headsail sheets. For our boats with ~95% headsails, this will be a small, lightly loaded pole. A spinnaker can not be sheeted over an outrigger.

A possible lawyerly loophole is to install the bowsprit and also attempt to run a JC length, mast-mounted spinnaker pole. Our rules still require a bowsprit, note the "shall" in 5.5.3 (below).I believe an earlier version of the ERS defined a bowsprit as a special case of spinnaker pole; the "near the stem" language was originally included to forbid mast mounted poles (JC length in our class) with their ability to project spinnaker tacks waaay out to windward. It is my opinion that the intent of our rules, in defining each spar permitted, and not including a spinnaker pole, should be read to exclude spinnaker poles.

Further, a big pole will be a real hassle to jibe on these little foredecks if you use asym kites. I'm having a tough time even picturing that- I've done it on big boats with crews of 6+ and trying to think how all those tasks get done on a small boat with 2-3 crew? If you go with sym spins it's not such a big deal, except, well, you've dragged your boat back to 1985 or so.

5.5.3 The bowsprit shall be attached near the stem by any means available.

The yardarm is just as you say, a device to increase the width of the head of a sail. This is a remnant of some of the rules put forward by a Sydney based sailor that used some of the prohibitions modern 18's now have, against some of that creative class' weird historical developments.

I hope this helps, and I enjoy the thought you're putting into your build, as well as recalling some of the people and discussions that lead to these rules!

Thanks Chad.

Having watched the J70s do periodic wing-on-wing it struck me that a whisker pole would make that easier. I did not see jibing as an issue per se because it is an asymmetric chute: I saw the whisker pole (although I suppose by its use it is a actually a spinnaker pole) as helping to keep the chute flying when wing-on-wing. (I used the term whisker pole because I envisioned a 'pin end' outboard rather than jaws.) I didn't see it as a reversion to classical symmetric chute tactics but an occasional exploitation of wing-on-wing tactically (for example, on a very biased downwind leg you might do the long reach first and then go wing-on-wing to the mark, setting up for an easier spinnaker drop). I haven't actually thought of where you would store such a pole, which is another matter. I once made a whisker pole for day sailing on my Soling and it was an absolute stinker to hide away between its very rare use.

I struggle a bit with your interpretation of intent in the class rules. To use the ISAF model, our class rules are 'open' rather than 'closed', otherwise we could not try all of our individual ideas. Unlike the (say) Laser or Optimist, where everything not specifically allowed is illegal, our class rules better fit the 'open' model, where it is OK to do anything, as long as it is within tolerance (where specified) or not specifically prohibited. So with a yard arm as you describe it, it could be argued that a spinnaker pole for booming out the chute is not illegal, because the rules are silent. It may be moot given the practicality of hiding a long pole that would only be used rarely, but at the time of any future rules updates one might consider whether an explicit prohibition of whisker and/or spinnaker poles was warranted. Maybe an experiment will show that it just isn't worth the aggrevation, in which case who cares?

Chad,

Supplemental to my previous post, I see your point about RRS (and should have seen it before: blush).

Whisker poles and Spinnaker poles are outriggers per RRS 50.3(b). Conventional use of a spinnaker pole is OK because the spinnaker tack is attached to the pole: it is not sheeted through the outrigger. RRS 50.3(c) specifically allows headsails to be sheeted through a spinnaker or whisker pole, as long as a spinnaker is not set.

RRS 50.4 and Class Rule 5.9.1 make similar distinctions between headsails and spinnakers (from opposite points of view), so while a narrow-shouldered asymmetric chute might measure as a headsail, and could be sheeted through a spinnaker or whisker pole if it did, class rule 5.8.1 prohibits tacking down a headsail forward of the forestay attachment point, which would make my occasional use of a whisker/spinnaker pole somewhat pointless, since I would have to transfer the tack to the stemhead before setting the pole (and who would do that?). Class Rule 5.9.1 also imposes a implied minimum girth on a useful i550 spinnaker tacked down forward of the forestay attachment point, which might be a useful explicit addition to the class rules at some point (With two spinnakers allowed a narrow 'chicken chute' is not out of the question). As an aside, the Gougeon's Everglades Challenge i550 didn't measure in a number of ways - the keel for example - but one not necessarily recognised was that the use of a genoa instead of a spinnaker on the sprit, broke class rule 5.8.1.

I will go back under my rock .......

Hi Warren,
I do agree with your view that these are generally open rules. There are a lot of areas very deliberately left open for exploration of new or even weird ideas.

One idea resolved early on was avoiding the sort of "gotcha" application of the rules, either by builders against the Class, or by the Class against builders. This is expressed in the Constitution this way:

8.2.6.4 In deciding any question the intended meaning of the rules shall be considered
rather than any technical misconstruction that might be derived from the wording. Extenuating circumstances may be taken into consideration for i550 Class rules if the wording requires interpretation and no deliberate attempt to gain an unfair advantage has been practiced. Precedent and the established policy of the i550 Class shall be taken into consideration in interpreting any rule of obscure meaning or not covered at all.

So I see the Class Rules listing "5. Rig Requirements", and then including a bowsprit but not a spin pole (taken alone, this might not be a sign of Class intent), but how then do you measure the length of your spin pole? JC is defined:

5.6.3 JC (JSP) measured from the forward face of the mast to aft side of spinnaker tack line when held perpendicular to the bowsprit spar shall not exceed 148" (3759mm).

Also, if a spin pole is permitted, what purpose is there in limiting the bowsprit's attachment to "near the stem"? The projection to windward of a spin pole vastly exceeds that of a stem-mounted articulating bowsprit, so why limit the bowsprit if the pole can do a much more effective job?

5.5.3 The bowsprit shall be attached near the stem by any means available.

Taken together, along with the fact that this topic was specifically discussed and decided against during the rule formulation stage, I'm pretty comfortable deciding that the use of a JC-length, mast mounted spinnaker pole is outside of the intent of our rules, even if there is a way to
"technically misconstrue" and derive an alternate meaning from what is the clearly envisaged by the rules.

And, I hope the tactics that work on J70s are not required on an i550 -sportboats don't need to do wing and wing like that, I hope!

Chad,

In the end we are on the same page because the RRS simply won't allow what I was suggesting with a boomed out asymmetric spinnaker ..... it is something of a surprise though, to discover that a chicken chute with midgirth less than 75% of foot length would be illegal if flown from the sprit. Not at all part of the original discussion! Maybe it is of no import: I suspect an i550 would fly under white sails alone in winds that needed a spinnaker that small.