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#1
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| moving jib tracks...pros vs cons Well...I am making slow but steady progress on a re-model of my '83 Hunter 20 into a light coastal cruiser.... I have extended the cabin aft about a foot and removed the pop-top roof and framed out an arched roof with two teak trusses and white wood stringers and begun to prep for hard coachroof replacement that will be a few inches higher and allow me to walk on this area of the boat in the future if needed. I am also widening out the cockpit seats after cutting out the coamings significantly and will blend the new coamings into the new rear cabin wall.The wider seats will allow for cockpit naps and possibly a tent to fit in this area. The new companionway will have an entrance "step sole" at least a foot higher than the old set-up to discourage water entry and the new rear cabin wall surrounding the companionway is now perpendicular instead of angled forward as before. The new plumb wall will facilitate more room for the person in the aft side of the dinette table/ settee berth...allowing a person to slide into that area much more easily and this seat already had the most headroom in the boat....just was hard to squeeze into... This new "vertical"wall will also allow easier and " tidier" installations of electronics and switch panel,etc and a better aesthetic overall in the cabin. In the one pic...you can see where the old cabin wall had been...My next big decision... is my wish to move the jib-tracks off of the catwalks on either side of the cabin and onto the outer edge of the new hard coachroof....this would allow a less cluttered catwalks leaving only the chainplate "u-bolts" and their attached shrouds as the only real obstacle one has to skirt while going forward on this small 20-foot sloop. My question: What are the potential rewards and drawbacks to the operation of the jib(s)/staysails if the tracks are moved there? It would seem that I could expect more close-reach performance...being able to clew the staysails more inboard...but will this affect any other performance scenarios and how so? Any helpful ideas and comments are appreciated...
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#2
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| Moving tracks inboard, provided your genoas / jibs will not conflict with shrouds, will help to sail closer to wind. At worst, you will be able to sail at same angle to wind, but with jib set at slightly bigger angle of attack, and thus more "powerfull". I speak here from experience mostly, no consistent teory background... I tried, and to it did work perfectly. Moving tracks on the cabin roof, however, could create a nasty structural problem. As it appears from the photo, your tracks will be just above long window. It is not the best of places to support upward pulling fittings. A SUBSTANTIAL stringer, spanning all the window, and extended well past it (~1.5 feet / 0.5m) forward and aft. Substantial I mean for example, glassed over wood ~80mm high by 40-60mm wide, or something similar in size, made of fiberglass only (It is a wild guess; I could calculate necessary scantlings, having displacement of boat, length of window and thickness of roof in the area). In no case jib tracks should be bolted to sandwich panel! If the roof in the area has sandwich construction, core should be removed, and the area generously glassed over to make it thick and solid. Good luck with Your project.
__________________ All the stresses in my designs are 95% of permissible. Last edited by Perm Stress : 02-14-2010 at 02:03 PM. Reason: spelling |
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#3
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| Thanks for your insights Perm...This is why I needed to address this now..as I am getting ready to finalize any structural elements still required in the new cabin roof. I will try to post anothersome specs and a pic of the new trusses and stringers in that area of the new framework..I am using epoxy and glass and was going to build up extra thickness on the cabin shoulders to mount the jib tracks there...with possibly an added bulkhead below as part of cabinetry/countertop/storage areas to anchor each shoulder more to reduce movement..just not sure how thick to go in the shoulders without adding excessive weight...The windows are large there and I was considering strengthening the area by crossmembering strips of marine ply over parts of the existing windows..making them smaller and then using bronze portholes that are rectangular and much smaller than the current window between the plywood uprights...if I cant find these at a good price(I have two brand new 7x14 bronze..but they are too big with the lower lip jutting out...anyone wanna them at a good price lets talk)...
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#4
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| Leave the track where it is and use a Barberhauler. |
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#5
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| Speak to the sailmaker see what they recommend as the right sheeting angle and check it against what you have. There may be no point in moving anything! On the other hand its not unknown that a production boat can be improved!
__________________ Never trust someone who can't say 'I was wrong'. |
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#6
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| Well.... I don't like where the track is now.....I think you are referring to an in-haul btw...a barber-haul is used to take the jib-sheet to a more outboard position I believe...They may have had to beef up the cabin structure but others have moved jib tracks onto the cabin and gotten more close-hauled performance...probably had to experiment in some cases...I need new sails anyway...and will adjust my rig for this to work If I have to...uncluttered catwalks are important to me I guess...its a small boat...the successful mods like this I read about somewhere were smaller boats I believe...with smaller jib loads on the cabin shoulder strength naturally...and thanks Zed...I probably will have to experiment with sheeting angles using my old sails first...there is a sailmaker who lives a few doors down but I have been waiting to approach him when I need new sails..he owns Atlantic Sails in Sarasota...just been too broke and now I am glad I waited for new sails...There are so many things on production boats that can be improved actually... can be rewarding when your upgrades work I suppose... most of mine are still in the pipeline...thanks everyone for your comments so far...in order of pics left to right...1) new frame with two teak 1x4 trusses to take the brunt of weight above...with white wood stringers...2) the dinette/main berth table 3) old pop-top and hatch Everything in the new roof frame will be encapsulated in epoxy then covered in epoxy and cloth/mat and painted white...this should give a good light quality in the cabin I am going after an " upscale workboat" look for the cabin in general...with lots of light reflectivity and not alot gloomy dark teak everywhere...I have some concerns about condensation in not having a sandwich roof but I am going solid fiberglass cloth over the frame at present..as light and few layers as possible to keep weight down
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#7
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| Jib track reinforcement There is simple, cheap and effective way to reinforce cabin roof for jib tracks. See a picture.
__________________ All the stresses in my designs are 95% of permissible. |
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#8
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| my dear chap your track needs be parallel with C/L sheet angle 12 degrees max Barber haulers are a pain in the neck or head or hair whatever |
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#9
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| .Perm..that looks like it could do the job for sure...it's going to be tricky to incorporate onto the interior ceiling with those flanges though...that is a strong installation though so I will see if I can come up with a way to get something like that up there for backing plate... Whoosh..I think I can just extrapolate parallel marks off the old track line to get that correct 12 degree angle...since It will be tricky for my poor geometry skills otherwise to find C/L...thanks guys... ![]()
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#10
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| Finding a good approximate centerline does not require much geometry. If the mast is in the center of the boat, it usually is, then tie a string to the forestay deck fitting and pull it taut when it touches the center of the mast.. That'll be the centerline of the boat within reasonable tolerances. |
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#11
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| Then a small protractor?..I guess a bigger one could be jigged from a small one...you gotta help me..I'm a product of late 70's/early 80's public schools... ![]()
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#12
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| Draw a 24" long line. At the end of this line measure up 5" and connect this point to the beginning of the first line. The resulting angle (makes a V shape) is so close to 12 degrees that you can not measure the difference. |
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#13
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| Okay...sounds good...thanks Hunter25..by the way..you sail a hunter25 I take it? I hear those were decent boats..some were cherubinis if I'm correct...
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#14
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| hi another option is having a ring that the sheets go through then youpput two pad eyes one near the rail and one by the cabinthen you have a small purchase systematached to each pad eye and a bungy going up to some thing. this is the system they use on the Volvo boats its light,cheap and easy to go out board. |
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#15
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| Ned, Thanks..that's a great idea...I think having a ring out on the edge of each rail is a superb idea...would probably use that location alot...and then if things get touchy..I can pop the sheets thru the snatch blocks of the cabin shoulder tracks and really get some inboard leverage when I need it...
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