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Jaws up or jaws down?

16K views 15 replies 12 participants last post by  PaulinVictoria 
#1 ·
The spinnaker sheet discussion below has started a side-issue about the favored direction of the spinnaker pole jaws on the mast and guy. I rig mine jaws down for a number of reasons: 1/So that inadvertent releasing of the jaws doesn''t bean someone on the foredeck, 2/ so that the guy''s pressure (when the sail is pulling up, the way we like it to) doesn''t bind the pin so it won''t release, 3/ so that the guy tends to fall out (due to gravity) when the jaws are opened*, 4/so the pole doesn''t have to be rotated to be dropped and locked into its deck chocks. 5/so you can open the jaws, hook the pole to the mast and not have to continue holiding it up while you trigger the pin shut. We sail a fractionally rigged J/36 with a 1000 square-foot chute on a 65'' mast. Sometimes it blows hard enough for us to use double sheets and guys. What do you do?

*This may work especially well on Long Island Sound because of the generally light wind, too.
 
#2 ·
I have been asking around town and I have yet to find anyone who has sailed on a boat with the jaws down. That includes one ex-America''s Cup crew man. I thought maybe the guys who race offshore might have sailed on boats with jaws down. In the past couple weeks I have yet to find a person who sailed on a boat that rigged the pole jaws up, although I liked the New Zealander''s answer that you must be a Kiwi and it only looks upside down from here.

I was also taken by your comment that the chute on the J-36 that you race on is 1000 square feet. The normal J36 chute is just over 500 sqare feet. Are you guys flying a masthead chute with the original penalty pole? If so what did you do to the rig to take the side loads of the chute? I am halfway considering going to a masthead chute fro cruising. (It kills your rating for racing except under IMS.)

Jeff
 
#4 ·
I''m the one who asked the question about the sheets & guys in the first place. You''ll be pleased to hear I''ve confirmed with spar and sail maker and we will be free to rig jaws up or down! Our pole ends are the trigger type which lock open until you bang them in when they fire (mind your pinkie) ... Would that influence any one''s decision to go jaws up or down? (splitting hairs!)

More seriously can you take me through the gear you rig on each of the four sheet/guy ends at the clew end? Some of the previous answers were not at all clear. The terms used were maybe americanisms, but I have tested them out and not even professional riggers in UK could understand!
 
#5 · (Edited)
I am probably the purveyor of the terminology conundrums in question. Starting simple:

-''Tack'' is the corner of the chute at the pole.

-''Clew'' is the other corner of the chute that is not the head.

-''Guy'' is the line that attaches to the tack of the chute passing through the pole end.

-''Sheet'' the line that is attached to the clew on the chute and runs aft to leeward.

-''Lazy sheet'' is the sheet on the windward side of the boat and which is not in use because the guy is being used.

-''Lazy guy'' is the guy on the leeward side of the boat and which is not in use because the sheet is being used.

-''Pole lift'' is a halyard that lifts the outboard (forward) end of the pole.

-Pole downhaul'' is a line or tackle located at the base of the mast that pulls downward on a pole end to keep it from ''skying'' or rising uncontrollably.

-''Foreguy'' is a line that pulls down on the spinnaker pole from below and forward that is used instead of a pole downhaul. It stabilizes the pole end better than a downhaul but requires adjustment every time the pole is adjusted.

-''Bridle'' are the two cable systems that are attached to the pole (one up and one down) that the pole lift and pole downhaul (or foreguy) attach to.

-''Twing'' is a line or tackle that has a block or fairlead on the end. The twing is located at the normal position for the guy lead block (i.e. half way between the spinsheet lead block and the shrouds). When you jibe, the twing is tensioned on the spin-sheet pulling it down to the deck at the proper lead for the guy. When you use twings you don't use separate guys.

In terms of hardware, when you use lazy sheets and guys, the sheets should have a larger bail on the snap shackles so that the guy can be attached to that bail with its own snapshackle. In lighter winds or on long legs, the lazy guy is removed from the sheet so that its weight won't affect the flying shape of the chute.

I am not sure if I used any other terms but those are the one's I think I used.

Jeff
 
#6 ·
Checked my info on J/36''s sail areas. J/Boats brochure states 1000 sq'' for the spinnaker. Though I haven''t taken out my tape measure, our I measurement is 44'' and J is 14. After seeing the way it drapes on the forestay in a typical Long Island Sound summer afternoon, our chute has to be closer to 1000 than to 500 aquare feet. Have daydreamed about a masthead chute, but the one we have has pulled us up to 13 knots, and, as suggested, we don''t want to pretzle the top 12 feet of the mast, either. Now, about those pole jaws...
 
#7 ·
You want the outboard end (at the tack of the spinnaker) to have the jaw opening facing up. With the jaw facing down, in a gybe, the pole will not drop off the guy and swing to the new guy. It will hang up on the old guy. This assumes you do dip-pole gybes. Jaw down ends would probably make end-for-end gybes harder as well.

If there is a risk of having the pole drop off the guy unexpectedly and hurt someone on the foredeck you should have the jaw serviced so it is reliable. Also, the pole should not drop as you should be using a topping lift to support it.

If you find that the guy will not lift out of the pole in light air you may have to ease it slightly once the pole jaw is opened. In more air the sail should want to lift, and will pull the guy up out of the jaw once opened.

The mast end jaw opening may go up or down, based on the mast ring size. If the ring is too small the jaw may bind or break when the pole is let down. I usually keep both my jaw end openings facing up on a Cal 40.

--Kevin
 
#8 ·
Kevin, I think you explained it very, very well. However, with a pole outfitted the same way on each end and with matching bridles for end-to-end jibes, the tendency for someone new to is to use it "upside down"...it seems more logical. This happened on my current boat with a new foredeck, and after he could not get the outboard end up and free of the rising (old) guy; we ended up with a ruined mast car. The pole mast end twisted and temporarily jammed in the car ring. He had sailed with me a few times and was a great person to sail with, before he moved away. The pole is always set with the jaws opening down now. We use trigger lock ends and attaching to the mast and "new" guy is not a poblem. In very light air, I would think either way is functionally not a problem, but jaw opening down would work best for me. Jaw opening up and I would probably get confused. I have a 30'' ULDB with an 800 sq. foot masthead spinnaker. This sail is not very forgiving and demands good handling, but, oh, how we love to plane.
 
#10 ·
I sail a J27, and the majority of my crewing has been on boats that jibe end-for-end. On the one boat that did a dip, I was taught to rig jaws up so that gravity would help release the guy when jibing. Same logic given for end-for-end, and pulling the new guy down was thought to be easier than pushing it up into the jaws. A few years ago, when "self-latching" fittings came out, I was taught to rig jaws down, since you could simply pull the pole down over the guy and the mast ring. Another reason I was given for jaws up is that it makes it easier to take the pole down while the chute is kept flying (to do a "mexican" takedown, for example).
Currently, I have an older pole with standard piston fittings (If I replace it, I will go to self-latching). Anyway, my current foredeck, who is smart but lacks the 60 years or so of sailing experience that sometimes encumbers my judgement, has about convinced me that jaws down is the way to go. Because they find it easier, I think because it discourages the guy from flying out if she inadvertantly opens the jaws and because, when we pole out the jib to leeward on a reach, the piston does not impede dipping the pole. So I'm becoming a jaws down kind of guy. I still think on a large boat jaws up might be safer, but on a little boat you can manhandle your away around any problems you might encounter, and the pole can be stowed so quickly we never have to do a "mexican".
 
#11 · (Edited)
When one needs to "blow the tack" one normally needs to blow the tack "RIGHT NOW" and that isn't going to happen with the pole's jaw's facing downward such that the guy is captured. With that one's only alternative is to let the guy run, with the mayhem that will entail. BTDT....Darn near broke the boat.
 
#13 ·
Resurrected OLD post (2002!!) but probably worth rehashing..;)

For me the end-for-end pole should 'hang on the pins' meaning jaws up. As mentioned the guy will 'lift out' cleanly most often. It also means getting the pole off the mast ring is a 'release and drop' rather than 'release and lift' - also easier to do, IMO.

With dip pole setups, jaws up again so that the pole will drop cleanly away once the jaws are released.. We used to trap both active and lazy guy on the first gibe/set.. it made sure that the lazy guy didn't end up 'under the pole end' and impede the gibe. Subsequent gibes looked after that because you generally lift the 'new guy' up under soon-to-be lazy guy, leaving that lazy guy draped on top of the pole end (again so pole will drop cleanly away.)

That's what worked for us, anyhow....
 
#16 ·
We rig the J24 with the U rather than n, a simple twist of the pole and the line is free. The main reason (for us at least) is when there is pressure on the pole, getting it back on the mast ring you have more leverage pushing up to engage as you can get your shoulder under it than trying to pull it down onto the ring.
 
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