Edited by car_guy on May 24, 2019 - 08:23 PM.
Help with building a gin pole
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Posted: May 24, 2019 - 07:52 PM
Started building a gin pole for the 21se and have a few questions. Plan on mounting pole about 1’ up from pivot base so it’s 90 degrees to the mast, will this be an issue being too far away from the pivot? Besides bridle wires to stabilize the gin pole I plan to add some line tied to either side of the mast to prevent it from rotating, is preventing mast rotation a major concern? I’d imagine if mast were to rotate the pole could slip off and it would be disasterous. I do have a steel “U” bolted to pole so it’s unlikely it would actually fall off. Another comments or suggestions looking at what I built so far?
Edited by car_guy on May 24, 2019 - 08:23 PM. -
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Posted: May 25, 2019 - 11:44 PM
How ironic. Just successfully used my gin pole on my first attempt on raising/lowering mast on my 21SE yesterday and today when sailing it for the first time. 3 ups and 3 downs. Worked like a champ and is easy.
I would not do it any other way, it worked out so well. I used the tramp lines to stabilize the mast and keep it in line an then used bridle lines to the front cross beans outboard of the taper pins. When raising, however you have to stop and loosen the trap lines about 3 or 4 times, just a hair each time as the curved beams/cross bars don't allow a perfect winch up or down. Have to stop and tighten on way down, but not as often.
Pretty much ever thing has to stay inline and tie or otherwise secure gin pole to mast. Doesn't matter that it's not at the vertex of the pivot as the pole is merely changing the angle at which you are tugging on the mast. It's your stabilizing lines that matter more. Do it first in a calm, wind-free environment for the first time.
Had an absolute blast today-low 80's, winds out of SE about 15 knots, steady all day, with occasional gusts a little higher. Had her up on one hull or just barely in water much of the time.
Wore clean stink out. All laughs and giggles. What an awesome day!
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Chuck C
NACRA 500 Mk2
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Posted: May 26, 2019 - 08:33 AM
the guy i purchased my mystere 5.5 from set up a gin pole for his supercat
while testing, the setup required a bunch of strap length adjustment - (same for me when i set up my easy-step for my h18)
before he had it dialed in the mast swung wildly and took out a window on his house
he went to a box store and had the new one in before wife got home ... lol
moral of the story: you may want to move your boat away from your house during setup - ymmv -
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Posted: May 26, 2019 - 10:25 AM
I was planning on making two loops using wire rope so I could raise the attachment point for trap and bridle wires to prevent retensioning mid lift as I thought that could get a little hairy... what do you do just use a few wraps around crossbar with some half hitches?
Thanks MN, that’s just a little shed in the pic but I usually wheel boat to to middle of yard when dealing with the mast. -
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Posted: May 26, 2019 - 11:09 AM
I experimented with gin poles on my H18 and P19 but the tensions and loads scared me. It was like something could go really wrong at any moment. Probably misplaced paranoia on my part, but could not get comfortable with it. So now I pay $70 a month for mast up storage at the harbor.
I noticed you are using your forestay, which I presume is the reason you need to position the pole up the mast a bit to keep at 90 deg. I had my gin poles set at the very bottom of the mast at the casting, and used a loop of amsteel line, looped through the shroud tang shackle, then to a winch on the trailer for hoisting. Basically a double line. Once in position, I would rig the forestay. Then I would unwind the winch and retrieve the line by pulling one end out. The downside here is that there was no way to rig for lowering the mast. Looking at your setup, my only concern would be possibly denting the mast. But if you've done this with success already, it should be fine. The boat does not appear to be strapped to the trailer. I would think the lift early in the process could pull the boat forward, but maybe not.
Earlier in the year, before the mast up storage was available, I sketched out a design with a telescoping bracket rigged with blocks that would lift the mast from the rear beam, inducing the same forces as lifting it by hand. Redesigning it 4 or 5 times on paper, I think I have something that would work. But, like the pole, it could start scaring me again once I tried it in practice.
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Bill Mattson
Prindle 19 "Gelli Bean"
Prindle 19 "Cat's Pajamas"
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Posted: May 26, 2019 - 07:47 PM
(how do i post a photo?)
Edited by dmydlack on May 26, 2019 - 08:53 PM.
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Prindle 16
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Posted: May 26, 2019 - 07:55 PM
https://photos.app.goo.gl/SwEzZHLAggTZ28n46
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Prindle 16
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Posted: May 26, 2019 - 09:57 PM
With the 21SE, I THINK you don't have a choice but to re-tension the pole as it lifts or lowers because of the geometry of the curved cross bars. Lowering is easier as its loosening and you can feel the amount of sway and if you have help, they can assist keeping the mast in line by pulling on one of the shrouds.
I use something like a truckers hitch, because when i loosen, i can pinch the knot to release tension on the tramp lines. That's probably not good description/advice for most not comfortable with managing heavy loads/rigging. Better would be a way to mechanically control tension via something like a cam cleat. The gin pole bridals don't change enough tension to mess with. I'll try and get some pics of my rig installed.
BTW, there's a video of a guy busting a tramp line due to excessive tension during a raise on a 21SE. Scary.
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Chuck C
NACRA 500 Mk2
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Posted: May 27, 2019 - 07:49 AM
i assume you are talking about a trapeze wire -
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Posted: May 27, 2019 - 09:23 AM
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Prindle 16
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Posted: May 27, 2019 - 08:10 PM
Given that the consequences of a failure in the dog clip are quite sever, I'd use something that actually had a load rating, such as the Maillon Rapide link, like you have attached to the front of the gin pole.
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Brett
2012 Goodall C2 with 2014 Hulls (warranty)
1992 Hobie 18 w/ SX Wings (Sold)
Tucson, AZ
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Posted: May 27, 2019 - 08:13 PM
Given that the consequences of a failure in the dog clip are quite severe, I'd use something that actually had a load rating, such as the Maillon Rapide link, like you have attached to the front of the gin pole.
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Brett
2012 Goodall C2 with 2014 Hulls (warranty)
1992 Hobie 18 w/ SX Wings (Sold)
Tucson, AZ
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Posted: May 28, 2019 - 02:29 PM
Yes, I meant "Trap wire", not tramp... Shouldn't drink and type.
Uh, I have to echo Brett's sentiment; I broke a less than adequate rope over the weekend serving as my gin pole bridal; wasn't a big deal because I had 1 guy each on either shroud holding the mast in-line. Doing it solo would have been a problem. The gin pole bridals didn't suffer from near the tension change as the trapeze wires. In thinking about that and failures, I'm thinking of hooking the 2 trap wires up each side, independently, with one having the maximum amount of slack needed on each side to serve as a safety should anything give way on the tighter one. I've been using rated, locking carabiners for the hook-ups (???). A way to reliably and safely release just a little tension as the rig comes up would be nice, because as I think about it, mine relied on me not slipping. Would rather, when released the line locks up on the trapeze line tension.
I'll re-rig next time and shoot pics...
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Chuck C
NACRA 500 Mk2
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Posted: May 28, 2019 - 04:34 PM
All due respect to the poster. looks like a system that works fine but I have several concerns with the images posted above
how is the wooden pole held in place? looks like friction alone. seems like a liability
the line used as the bridal/anti-sway are the same line - if it breaks in 1 place it will effect other location
this same line is not secured to the beam / eye bot (port side) - it is looped around the "dog clip" this could very easily slip - again effecting more than 1 line / area of support
the anti-sway cables are connected to the front of the mast via an eyestrap (i assume there are no trap wires to do this):
1. if a line breaks i have concerns those small rivets are gonna hold the mast up - and if they rip out... that is a bad spot for bent up metal
2. that eye strap would eat up my jib leach
3. how do you get them off the mast after stepping? (looks like it's kinda high up the mast)
here is a vid of a guy with his trap wires connected to his h18 beam (notice the beam is also curved)
https://www.youtube.com/watch?v=-VEx8-xIzw4
I am not a fan of how his traps are connected to the bridals - same reason as above - if one line fails ... it could cause issues with the other safety systems (i.e. if a bridal line breaks .. .it could cause the anti-sway line to fail)
Edited by MN3 on May 28, 2019 - 04:41 PM. -
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Posted: May 28, 2019 - 05:04 PM
All good points!
- The wooden pole has a pin sticking out that fits snugly into a hole in the mast (not visible.)
- The line is one piece but the binding loop-throughs don't slip. This I tested by putting it under load with a winch. If one section broke (really unlikely with 1/4" Dyneema!) the other sections do not directly receive the lost load (the loads are 90 degrees off axis.)
- Trap wires come in from a much higher, more oblique angle so the leveraged loads are much greater (and the mast center is unsupported.)
- The rivets holding the eyestrap are Monel - same as the ones holding on the hound. The anti-sway lines are never nearly subject to the full loads that the forestay or other standing rigging supports. And, the sway is gradually taken up by the shrouds in the last 85% of the raising -- just when the mast could exert the greatest swaying force.
- It's a pretty curvy low-profile fitting that eyestrap; we'll see!
- I mounted the eyestrap just within my reach standing on the forward beam.
All the best!
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Prindle 16
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Posted: May 28, 2019 - 06:15 PM
Great answers! I didn't see trap wires in the images but i am happy to see your responses.
you seem to be a very "handy" sailor - so i hope i don't sound like i am preaching or being argumentative : with all the respect in the world ...
My only concern is that "loop" (port side / dog clip) : i am certain under a few circumstances .. that loop will pay line out
that loop is a simple luggage tag (used all the time with spliced end/eye splices). I have used this "binding" many times in many scenarios - I have tried to use this on my jib clew and spinnakers - it fails (slips) even with non dyneema.
this is not secure, esp using very slick non jacketed high modulus line (dyneema), just a smidge of slack in that tag and it will freely pay out... add some water to that somehow and it's even slicker
I always try to prepare for worst case scenario - ymmv:
if somehow the port bridal line fails it could pay out and now you have lost the mast lower guy line too.
Edited by MN3 on May 28, 2019 - 06:33 PM. -
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Posted: May 28, 2019 - 06:28 PM
carabeeeners are great - as long as they aren't the one's that come free with a water bottle :)
i even trust those dog clips pictured above if they are marine grade - i have a brass one that has lasted me 19 years
a rolling hitch knot could work
it's a very simple knot ( a 1/2 hitch and a double 1/2 hitch) and it is adjustable.
under load it can only loosen but if it's not under load it can slide either way
my buddy uses this knot all day long to secure himself up a 50-90' mast (he's a rigger)
https://www.animatedknots.com/rolling-hitch-knot
even better - Modified Rolling Hitch (Camel Hitch)
https://www.boatus.com/ma…2013/June/get-a-grip.asp
Edited by MN3 on May 29, 2019 - 11:19 AM. -
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Posted: May 28, 2019 - 07:10 PM
Your concern has convinced me. I'm onto a reconfiguration! Thanks!
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Prindle 16
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Posted: May 29, 2019 - 09:07 AM
I am really liking this thread. All good information. I like the white oak 2x4? To hijack for a moment, Will a gin pole work on a non-captive mast base on a N5.0? Seems like as soon as you winch it, it will slide forward onto the ball and stay put for the remainder of the trip up. I have mine stored upright, bought it where it is stored, and have never taken it down.
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FYC, Nacra 5.2 "Chris's Flyer" & Nacra Playcat & Farrier Tramp
Previously owned: Trac 14, H14, H16, H18, N5.0, G-cat 5.0
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Posted: May 29, 2019 - 09:44 AM
I got an oak stair railing section at HoDo (apx $30. for 7'.)
Dunno the N5.0 but on my mast without the fat pin, (not visible) holding it in place, it would slide off at the wrongest moment.
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Prindle 16
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