Gin Pole
Printed From: Laser 28 International Class Association
Category: Laser 28 General
Forum Name: General Forum
Forum Description: All the topics that don't fit elsewhere
URL: http://www.laser28.org/forum/forum_posts.asp?TID=617
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Topic: Gin Pole
Posted By: Seawolf
Subject: Gin Pole
Date Posted: 29 January 2013 at 2:39pm
| Considering making a gin pole to assist in raising and lowering the mast. Has anyone done so for their Laser? If so could you please share some ideas on materials, length and setup. Thanks. |
Replies:
Posted By: frfletch
Date Posted: 01 February 2013 at 12:02pm
| Not sure how a gin pole would be used. What do you have in mind? We use our spinnaker pole and fix a block to the end fitting. The system surely benefits from a manual assist with someone walking the mast up from the back when the angles are most acute on the spinnaker and jib halyards used for lifting, but it all works. We use the same set-up for the take-down. |
Posted By: WJRyan
Date Posted: 01 February 2013 at 3:08pm
|
It would be helpful to know how you do that, I don't have to put mine down every year but this is a show stopper for me traveling - if there was a better way please share with those of us who don't know (okay, with me!). :)bill ------------- Bill Ryan, Room4Crew, #155 |
Posted By: Seawolf
Date Posted: 01 February 2013 at 3:53pm
|
I second that! We trailer home every year at the end of the
season. So a better/safer way for short handed crew would be much appreciated. I have you-tubing and researching Gin Poles,
but haven't found a "how to" manual. I have been toying with fabricating an extension from the front of the trailer, basically an extendable pole with a winch to hook up the spinnaker halyard. It would raise the anchor point from the bow of the boat to 3-4 feet above the bow. |
Posted By: frfletch
Date Posted: 01 February 2013 at 4:33pm
|
In historic Laser 28 history there is an article as to how to do this, but I will outline it since it is simple. Let's start with the take-down.
1. Firstly, for anything you do with that mast on top of the boat you must build a small "H" cradle, perhaps out of 2x4, which just consists of two verticals ob about 4' long, with a horizontal about 8-10" from the top to hold the mast when down. It helps to use a small square of plywood, say 3/8" nailed or screwed onto the two verticals just below the cross piece to stabilize this frame so that it does not fall into a parallelogram. This frame gets lashed to the push-pit and the bottom of the 2x4's sit on the little rear deck either side of the tiller head. This cradle is required because without it you cannot lay the mast down because it will destroy the coach-top and any vent you may have there, and you need this cradle from traveling anyway. 2. Fix a snatch block onto the spinnaker pole lashing it through the end beak. If you don't have a snatch block, then use a heavy duty stainless steel ring and clip it into the end of the pole. Now mount the pole onto the mast and stabilize it perpendicular to the mast just as though you were gong to hoist the kite with uphaul and downhaul. 3. Run the spinnaker halyard down through the block or ring and clip it onto the tack ring where your jib attaches. 4. Take one of the jib halyards and run it down straight to the front of the boat and attach it to the same place or any strong point (could be the anchor cleat. 5. Lead both halyards around winches and secure. They are not acting as forestays which allow you to detatch your forestay, which you will do now. 6. Be sure that all you mast wiring is detatched, and I would loosen the shrouds, counting the number of turns you back them off and write that down. 7. With a person on each winch, you can now start letting out on the halyards and lowering the mast to the back. I presume the boat is in the water and you must be in dead smooth water with no wakes around. This is because once the mast is down a few feet, there is no athwartship stability and you don't want the boat rocking about. Just easy off both halyards slowly. As the mast tips back, the tension on the halyards becomes high. Toward the end it becomes very high. At this point you have two choices which are of help. You It is perfect if you have places a piece of say 3/4" ply across the cockpit seats so that one person can stand on these and receive the mast and take up its weight and eventually help lay it in the cradle. Another way is to have some sort of yoke arranged on the end of a pole that will capture the mast and allow the helper to relieve the weight. The mast just is lowered into the weighting cradle. Note: Do not forget to disconnect the mast wiring. The boom must have been removed. The hold-down nuts at the mast base must be removed so that the mast can tip back on its swing pin. Putting the mast up is a reversal of this process. The reason I specify a snatch block or a heavy ring at the pole end is because if you run the halyard through the pole's end fitting, it has to bend around the piston and through the beak which induces huge friction. You can do it this way and it is not very critical on lowering, but lifting is made easier using my method. Last comment. If you have a couple of spare people, you can attach a rope through your second jib halyard fitting sufficiently long that it leads down both sides of the boat. The two spare people can then hold each end of that rope while standing either on a dock either side of the boat, or on the boats extreme gunwhale. By handling these lines they can add athwartship stability during lowering, but they must be careful not not put tension in those lines which will add to the tension on the halyards. They can just gently handle them so that the mast does not swing from side to side. Good Luck. |
Posted By: frfletch
Date Posted: 01 February 2013 at 4:38pm
Sorry for the typos. I should really proof read these things before sending. 
|
Posted By: Seawolf
Date Posted: 01 February 2013 at 10:52pm
|
I heard of using a spinnaker pole for the Gin
Pole, and your description make sense. Just want to check on two things, does
the spinnaker halyard place enough tension on the pole to keep the pole from
swinging side to side? And are you using the winches on the cabin top, or the 2
speed in the cockpit? Thanks |
Posted By: frfletch
Date Posted: 01 February 2013 at 11:13pm
|
The pole cannot swing from side to side because it is held forward by the halyard at its tip leading to the front of the boat. So much tension goes into that halyard that no one is going to make the pole swing. It's tight! It is the mast that one doesn't want to swing from side to side after it gets to past 45 degrees. That is more critical, but still not a big deal.
As to winches, I used the #8 Harkens on the cabin top. I those toy Maxwells that were original equipment for the cabin top might make me nervous. Again, not much in taking it down, but lifting imposes some loads. We use both halyards for lifting to distribute the load. The one that leads straight to the front of the boat helps, but it is not as effective when the mast is leaning far back at the beginning of the lift. Having said that, we have put the mast up without using the spinnaker pole and just gone direct with a couple of people helping to lift the mast from the back in the first stages of the lift. One could do that with all three halyards.......2 jibs and the spinnaker to spread the load. I want to tell you that the mast's balance point is just about at the spreaders. Also, the spreaders come down just in front of the cradle in the back. So when you go to take the pin out and move the mast forward on the boat, buddy has to be right at the back of the boat reaching behind the cradle. If you provide an email address I will send you a couple of photos of the referenced cradle and my mast on the boat when ready for towing. My email is kh1092@yahoo.com |
Posted By: jez rees
Date Posted: 07 February 2013 at 3:44am
|
A good argument for a bowsprit, as ours gives a good angle. I guess you are best to be about 6" forward of the bow. We quite often "Iwo Jima" our mast,my only comments would be that you must use a strong block and not a ring to grind the mast vertical. The friction without a block is too much to overcome. I usually just use a normal closed cheek block and secure a rope onto the forstay about 2ft up using clove hitches and multiple half hitches to get the angle right.
Although a little frame to rest the mast on and not damage the cabin top would be ideal, we usually just put a fender underneath plus a few people to lower her down gently. Watch for trapping the wires under the mast foot, we've done that but found the extra rake the "shim" gave us was very fast! |
Posted By: frfletch
Date Posted: 07 February 2013 at 7:15am
| A sprit would indeed help. Now I must ask how you find the performance of the boat with the asymmetrical compared to conventional? I recently heard of another Laser in San Diego that is said to be totally tricked-out and she is also set up that way and apparently successfully. |
Posted By: jez rees
Date Posted: 07 February 2013 at 7:55am
|
Performance wise I guess not much gain other than the simplicity and higher angle when reaching. Our gain on triangular courses is that we can gybe the ayso very easily when others are fighting their poles, the downside of this is windshifts or tactical mistakes which mean that we are flying the wrong type of spinnaker. Going deep on the ayso is painful unless in high winds.
The other advantage is that we now have an Ullman S2 kite i.e deep downwind shaped. You can't reach on this but it is more powerful on deep runs, somewhere we thought the Laser 28 is under gunned in mixed handicap fleets. At 46m2 I think this is still smaller than the class kite but the shape is better than the AP for downwind. But this thread was about a gin pole...... |
Posted By: frfletch
Date Posted: 07 February 2013 at 8:17am
| No surprises, I guess. Just curious. |
Posted By: meholden
Date Posted: 13 February 2013 at 5:17pm
When I did this (I've only done it one time) I used a 6 ft stepladder in the cockpit, lashed down so it's pretty stable. The mast sits there without hurting the cabin top. Climb the ladder as much as you dare to catch the mast as it comes down.
Does your pole downhaul go to the mast base so the pole and mast pivot together? |
frfletch wrote:Posted By: frfletch
Date Posted: 13 February 2013 at 6:02pm
| The downhaul always goes at the base of the mast. |
Posted By: Mad Max
Date Posted: 14 February 2013 at 1:38pm
|
On Mad Max we use a little different set up which requires 3 people. With the spinnaker pole lying on the bow pulpit we attach at the base of the mast. We lash it to the mast and tie off to the downhaul attachment to keep it in position (critical). We put a block on the bow where the jib is attached. We then run a sheet from the main winch thru the genoa car thru the block on the bow, up to the pole end and attach using a bowline. We then attach both jib halyards to the bowline. (use both for insurance as I don't want to put all the strain on one clutch). Take up on the halyards raising the pole off the bow pulpit about a foot. Now take up at the winch and undo the forestay and nuts at mast plate. The pole and mast now pivot as one. When the mast is down the pole is vertical. One person on the winch, one person behind the mast to help guide and one person to steady the pole to keep vertical. We've raised and lowered at the dock which can be scary with any kind of wave. Our first choice is on the trailer. The person on the pole is controling the direction of the mast, Once out of vertical the mast starts to swing with it. The person behind the mast helps guide and makes sure the mast goes into the crutch. Make sure the sheet you're using is long enough to get the mast down. On the stern rail I've built a 3' approx crutch with a 1' foot extension. It sits on the deck and is clamped to the stern rail. With the extension in place the mast will clear the cabin top. After the mast is down and positioned forward we remove the extension and the mast is in position for traveling. I've also built a neopreme (or what ever there made of) roller skate wheel into the crutch. With this set up one person can easily position the mast back and forth when working on the boat. ------------- Dick #122 |
Posted By: Mike V
Date Posted: 19 September 2013 at 10:47am
| I made a generation one gin pole. I made a shoe that fits around the mast to secure the pole. At the other end I welded two eyes in the pole. I attach a halyard to the top eye and lock the clutch so the pole is level. Then I used the mainsheet setup to the lower eye and to the head stay fitting. The pole is the same length as the J. I can now lower the mast with very little effort. I will keep everyone updated on generation 2. |
Posted By: frfletch
Date Posted: 20 September 2013 at 11:02am
|
Mike,
Where on the mast does the "shoe" fit and how is it fixed. Does the mast raise also happen with this set-up as easy as the lowering? I can see there would be a lot less effort loss in the compression caused by using halyards for raising and lowering. |
Posted By: Mike V
Date Posted: 20 September 2013 at 11:17am
|
The pole fits right at the base. I used the pole lift down haul to secure it from moving up the mast. I could raise and lower the mast with one hand. The original gin pole the shoe was a little light and it would bend too easy. My ultimate goal is the build it out of aluminum so it will not rust. Total cost so far is about $25.00
I will take afew pictures and post them. Mike |
Posted By: frfletch
Date Posted: 20 September 2013 at 11:35pm
| Looking forward to the pics! |
Posted By: Mike V
Date Posted: 30 September 2013 at 9:13pm
|
So here is the link to the pictures. I secure it to the base of the mast using the blocks for the pole lift and down haul. The other end has 2 eyes that I connect the halyard and the mainsheet. The shoe keeps it from going sideways and help keep it secure. I am going to add some lines the keep it from moving side to side. When I figure that out I will post it. The last time I dropped the mast we did it on the trailer.
https://www.dropbox.com/sc/gqug4hw9v0d63n5/S_VzH6a8sc |