I have started to play around with the mast butt position on our boat. We have an Allis adjuster that until recently just sat below unused. A recent stint racing Etchells, and the aggressiveness of adjusting the mast butt, deck chocks, and rig tension for the conditions made me think about the J/24 mast setup some more.

I found that .25" - .5" adjustment either way of the "neutral"/all purpose setting made a difference. In light air, I moved the mast butt back about a little more than .25", and the bottom of the main flattened out really nice, and the headstay retained it's sag. The next day, with breeze of more than 17-18 kts., I moved the mast butt about the same distance forward of the all-purpose position, and the headstay tightened up a lot. We had good point with the jib up (it was vang-sheeting conditions), and the boat seemed more balanced to the driver.

Now I need to go back and make some marks when we find a setting we like in practice so that we can drill more holes in the I-beam. I think that is stupid. I would prefer to make leaving the mast butt attached to the adjuster system legal, and not having to re-drill and bolt the mast butt down. I see a lot of people using 1/4" clevis pins to locate the mast butt on the I-beam, and not using threaded bolts/nuts.

I would like to add that a mast butt adjuster is a wonderful training and teaching device. In my opinion no other adjustment on the boat does so much for so little (mainsail fullness/leach return, forestay sag, and helm balance). In the old days, a genoa sheet back to each primary was way too cumbersome and awkward for anything other than an occasional use. I too created a homemade device using a bolt and a nut and a little welding after seeing such a device on a boat sailed by Mark Foster. After a little tinkering and adjusting (way too far forward and then way too far back), I began to get a feel for the response of the rig and the helm of the boat according to the mast butt position. Only then did I learn how a J-24 feels to be balanced. And I had been sailing J-24's off and on for over ten years! I must be a slow learner!! Along the way, I also learned about luff curve of the main and the sensitvity of some mainsails to different masts which all have varying degrees of stiffness. I certainly agree with the rule that forbids adjustment while racing. I also beleive that once you "know" your setting, very little if any adjustment is required. But for some folks, (not a beginner but someone who is ripe for the appropriate learning curve) this is a wonderful device and the class should even incourage such sailors to test their tuning wits by experimenting with different mast butt settings. The level of sailor in the class as a whole would surely rise.

As you can see the road to this point is long and a bit winding. Several years ago the stuff about mast butt adjusters was in rule 7 Prohibitions. However, as Will pointed out, a genoa sheet and the cockpit winches could be used to adjust the mast butt, so could a hammer and a foot. A technical committee member passed on the Allis Racing equipment saying that it did nothing that this other equipment did and that if it was not attached to the butt while racing it was just some extra equip aboard the boat......however the extra equipment argument did not hold water when rule 3.1.4.was examined. So the mast butt adjuster rule was moved to rule 8 - Restrictions while RACING. You cannot move your butt (mast) while racing but you may have the equipment aboard to do it when not racing.....same with a GPS.

I'm not saying I agree - but that is how we got to this point.

Steve

Geoff Just made me take another close look at my rule book. This just goes to show you that are an infinite number of detials to cover on the 24. Geoff is correct with his statement that device to adjust the mast butt position is illegal. But the rule says "any equipment or device to adjust the position of the mast at either the deck or the heel" is prohibited. Standard practice is to use the winches in the cockpit and a line attached to the heel of the mast. I hardly think they are saying that that method (generally done at the dock) or the equipment is illegal. Just as important to note is the presence of a quickpin on the device we are discussing, so that it may be detached while racing.

When I read Geoff's last note on this subject, it struck a nerve in me. I may be on the sailmaker side of the fence now, but it wasn't too long ago that I was a sail customer with an extremely tight budget. (I mean, I made a career out of used sails.) This device was suggested to me by the salesman from North who sold me my sails. He told me that I had to have it. I refused because I honestly didn't have the money to compromise. Because I didn't use it, I know there were times I was slow with those sails. It aggravates me that some of these toys are pushed on sailors without a full disclosure of the rules or the real need for the toy.

I would love to hear from Steve Podlich on this item. He's the kind of guy who has seen every infraction you can name (not on his boat, on others). I'm sure he has faced this many times and can shed a little light from the measurer's side.

Will Crump

Hi Tony,

You ask a very good question, and a topic that leaves me a little bewildered. When the J/24 class rules were written back during the Mesozoic Era , before the dinosaurs were exterminated by the giant asteroid, it must have been hard to visualize how popular the J/24 would become. The class rules have served us well, but they still contain remnants of primitive thought. In general, masts are too bendy in heavy air and they are too stiff in light air. So in light air most racing boats like to have a little mast bend induced. Usually this is done by placing mast blocks behind the mast at the deck. On a J/24, however, the mast position at the deck, or J dimension, is a measured position, and adjusting it is prohibited. So we go through extraordinary lengths to achieve the same affect by positioning the mast butt. (for more details see my boat speed guide www.shoresails.com).

In 1991 I worked with a local machine shop to create a device that would make moving my mast butt easier. It was removable and worked by means of a worm gear and a socket wrench. It worked very well, I could move the mast butt under full load and while sailing upwind! The problem was that it became very difficult to duplicate settings. Tiny adjustments at the mast butt meant that all the sails had to be dropped and the shrouds readjusted. I lost more races that year because I was frigging around with my mast butt instead of paying attention to the racecourse. Eventually, Bob Johnstone circulated a letter that declared my device illegal. A new rule was written, prohibiting “… the ability to adjust the position of the mast heel by any method. The connection to the mast heel of any adjustment device or equipment.” Imagine my surprise seven years later when a similar device showed up in the Layline catalog. I should have applied for a patent.

I concur with Will Crump, put your mast in an all-purpose position and leave it there. Concentrate on starting, and choosing the best side of the racecourse.

Tony,

It is not illegal to adjust the mast butt position, nor is it illegal to have device that can do so with some purchase or turnbuckle. However, it is illegal to adjust the mast butt position while racing (inside the 5 minute gun), and it is illegal to use only the mast butt adjuster to hold the butt in position. The butt must be "Bolted" into place.

For those of us who have had old boats, it is nearly impossible to find holes that line up exactly the way we want or have a "clean" I-beam to place the correct new holes in. So, I would not be surprised if some boats for the rule have the ability to bolt the mast into place, but in practice, they actually sail with only the turnbuckle adjuster holding the mast butt in place. To sail in that manner is illegal, but nearly impossible to regulate without a suprise boarding.

I sail with a mast set-up that keeps the mast butt bolted in one position for all conditions. While I recognize that some other rig set-ups potentially cause a boat owner to infringe on the rule you are concerned about. It does not seem to offer any advantage on the race course, and if anything, it is one more thing for that sailor to worry about.

I would not worry about "cracking-down" on this device. There is good reason for bolting the mast in place, and if someone chooses to break this rule, they may ultimately lose their rig. It is their choice and their price to pay.

Good Sailing
Will Crump

I have seen frequent mention of the advantage or even need for a device to adjust mast heel position. Such a device seems to be prohibited by rule 8.1.4. Is there any reconciliation of this apparent conflict?