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Do we need an A Frame ?

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britinusa
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Initially Posted - 01/11/2007 : 07:17:43

We're looking at expanding our accessability to places currently limited by the mast raising system being on the trailer. So do we need an A Frame in order to pass under fixed bridges?

Raising the mast is now a really straight forward process using the trailer winch, raised about 24 times now in just over 18months. We feel that we have it down.

But on the water we don't have the advantage of the trailer winch.
The Baby Stays do a great job of stabilizing the mast, so the only part an A Frame would impact is the leverage. So I'm looking to see if anyone has raised the mast on the water using baby stays but no A Frame.

I was wondering: If I had a finger pole of suitable size, could I attach it to the base of the mast or to the mast step, add a second pair of baby stays.

In the drawing below, I show the concept.
The Yellow line would be the 'Mast Raising Halyard' running from the mast head (perhaps the unused jib halyard) lead though a block on the bowlead. (Could be positioned on the top front of the pulpit with strengthening lines down to the bow cleats.) Then back to the cabin top winch (might need an organizer if it scrapes along the top front edge of the cabin top.)

The Blue baby stays would seem to be the best location pivot wise, but the green would be stronger.

So the plan would be to attach the finger pole to the mast at the foot (perhaps a SS Strap) Then stabilize it with the 2nd set of baby stays, using the original baby stays to stabilize the mast as normal.

Then simply take up the slack and tension the mast raising halyard, undo the pin holding the furler to the bowlead, and then control the lowering with wraps around the winch. The mast would end up supported in the aft mast support which we would leave in place.

Raising the mast would bascially be pretty easy as the setup would be in place and just involve taking up the strain on the winch (perhaps manhandling to ease the initial load) till the mast was in position and replacing the bowlead pin.

Ideas? Pitfalls?
TIA.

Paul.

Joint Decision. (Sold)
PO C250WB 2005 Sail # 841.

Moved up to C34 Eximius

Updated August 2015

Edited by - on

aeckhart
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Response Posted - 01/11/2007 : 08:08:31

Although I've not done it myself, the "gin" pole is the method most often used to raise and lower the mast on the water. The stays you describe will definately help to stabilize the mast. I use a similar setup when using a gin pole on my trailer.

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britinusa
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Response Posted - 01/11/2007 : 08:29:08

Al, thanks, what is a 'gin' pole used for though? I'm under the impression that a finger pole is for holding out the jib on a run. Is the 'gin' pole for a spinny/genneka?

paul

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Frank Hopper
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Response Posted - 01/11/2007 : 08:49:51

A gin pole is specific to raising and lowering a mast. I have never heard of a finger pole; whisker poles hold the clew of a an attached headsail and spinnaker poles hold the tack of free flying headsails.

Some people use their booms as a gin pole when lowering a mast forward, I don't know if putting a fitting on the lower front of your mast and moving the boom there when needed would be a good idea or not, it would depend on whether or not you would need to take the boom off when going under a bridge. If not then a dedicated gin pole would be better. Hunters come with them, one of their points of sale against the 250 is that you can raise and lower the mast on the water or trailer with their system.

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JohnMD
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Response Posted - 01/11/2007 : 09:45:02

My boat came with a 'gin pole' to raise and lower the mast. It's just a piece of pole. One end is smaller to fit in a hole in the end of the mast. You could probably use some sort of strap arrangement to attach it to the bottom of the mast instead so you wouldn't have to drill a hole in the mast. The other end has a foot long piece of cable with an eye on each end running thru it. One end of this cable attaches to a Ubolt permanently attached inside the anchor well. The other end to a halyard (either one). The original setup had a block and tackle arrangement that went between the Ubolt and the cable that was used to raise the mast. Arlyn has a neat arrangement that replaces that with a winch mounted on the gin pole. I think using 1 set of baby stays will be fine.

Have you figured out what the mast is going to sit on once it's lowered? That's the part I never could figure out.

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britinusa
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Response Posted - 01/11/2007 : 13:58:04

The reason I thought a 2nd set of baby stays would be needed is to provide lateral stability to the 'gin pole' I could imagine that when the pole was at it's maximum distance from the bow(ie almost vertical) the tension on the end from the mast weight and the halyard might encourage the pole to lean port or stbd. Shortest distance between two points {masthead and bow block) would tend to encourage that movement. Hence the 2nd set of baby stays.

Looking carefully at the layout, the stanchions are close enough of being abeam of the mast, so the 2nd set of baby stays could be secured to the lower part of the stancion (the regular baby stays are connected to straps welded to the stanchions.)

When the mast is down, it would rest on the transportation aft cradle (a pole set on a 2nd set of pintals on the stern) but I would have to extend that in height if I wanted to leave the boom attached. With a apropriate quick pin, the boom could be made easy to unhitch from the mast thus eliminating that issue.

Paul.

Edited by - on

Turk
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Response Posted - 01/11/2007 : 15:36:20

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by britinusa
 The reason I thought a 2nd set of baby stays would be needed is to provide lateral stability to the 'gin pole' I could imagine that when the pole was at it's maximum distance from the bow(ie almost vertical) the tension on the end from the mast weight and the halyard might encourage the pole to lean port or stbd. Shortest distance between two points {masthead and bow block) would tend to encourage that movement. Hence the 2nd set of baby stays.

Paul.
<hr height="1" noshade id="quote"></blockquote id="quote">

Here is a link to a system I made for a Catalina 22 I owned. The "A" frame telescopes and breaks down very easily. Leverage is awesome at 7 ft (A frame) 28 ft mast. I used the boom vang for block and it allows for you to stop and lock it at any point to free up lines , etc. This may give you some ideas.

http://www.elmhurstprop.com/mastraise/index.htm

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britinusa
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Response Posted - 01/12/2007 : 07:14:03

Thanks for that Link Turk. I have never fully extended our vang but would be really suprised if it has the same length as the one in your pics.
Our stern mast support is very similar to yours, it's mounted on a second set of pintals to stbd of the rudder. Your support seems taller, is there any particular reason for that extra height.

I'm still leaning towards the gin pole concept for at least two reasons.
a) We try and make things multi-functional. A stout Whisker Pole could also be uses as the Gin Pole.
b) I want it to be easy to stow and easy to put together on the water.

Some folks on the forum have used home depot paint roller extension handles as whisker poles, but I don't think they would be sufficiently strong, so I'm looking for other whisker poles.

Right now I'm considering line instead of steel for the 2nd baby stays, again, multi-functional (and line/rope must be about the most multi-functional piece of equipment on board

)

Paul.

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aeckhart
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Response Posted - 01/12/2007 : 09:01:57

Paul,

If you need a gin pole for on the water to get under a bridge or low wires, etc, you can use your boom. Just keep it attached to the fitting on the mast and lower it forward onto the bow pulpit. That way you can lower and raise it as needed and not have to purchase other equipment. You could probably use your main sheet tackle for the job. A new wisker pole will cost you around $200 or more and it may not be "stout" enough. A good spinnaker pole would be better but will cost even more.

To accomplish this using the boom you will need to set up to stays to stablize the boom from side to side. Attach two additonal "stays", one each from the stays used to stablize the boom (using steel rings)to the mast, secured to pad eyes as high up as you can reach. When tightened up, the mast and boom will be secure from side to side movement. A little manual assistance on the cabin top in less than ideal conditions may be needed however. You have to use very low-stretch line or nylon straps as stays. Straps with the ratchet-type locks on them are best.

I wish I had the techno skills to post a diagram. If you want I can email you one.

Edited by - on

Turk
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Response Posted - 01/12/2007 : 09:26:01

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by aeckhart
 Paul,

If you need a gin pole for on the water to get under a bridge or low wires, etc, you can use your boom. Just keep it attached to the fitting on the mast and lower it forward onto the bow pulpit. That way you can lower and raise it as needed and not have to purchase other equipment. You could probably use your main sheet tackle for the job. A new wisker pole will cost you around $200 or more and it may not be "stout" enough. A good spinnaker pole would be better but will cost even more.

To accomplish this using the boom you will need to set up to stays to stablize the boom from side to side. Attach two additonal "stays", one each from the stays used to stablize the boom (using steel rings)to the mast, secured to pad eyes as high up as you can reach. When tightened up, the mast and boom will be secure from side to side movement. A little manual assistance on the cabin top in less than ideal conditions may be needed however. You have to use very low-stretch line or nylon straps as stays. Straps with the ratchet-type locks on them are best.

I wish I had the techno skills to post a diagram. If you want I can email you one.
<hr height="1" noshade id="quote"></blockquote id="quote">

Sounds like a very good idea and is definitely going to be strong. I've tried ratchet straps in my design and unless you use the very large ones (10,000 lb), the small ones tend to stretch. I would still try to make steel cable stays for the boom. You already have the steels ones for the mast. You just add more rope to the boom vang to make it stretch further :). I used a halyard from the top of the "A" frame to the top of the mast. You could still use a halyard on the end of the boom.

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Frank Hopper
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Pitcairn Island
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Response Posted - 01/12/2007 : 13:41:42

25s have forward and aft lowers, we can choose which direction we lower our mast, 250s have swept back spreaders with a single aft lower, lowering forward would be a big hassle. I think a dedicated gin for going back where you will not need to adjust stays will be easier.

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britinusa
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Response Posted - 01/12/2007 : 14:39:40

Frank, you are correct about the stays. Our mast has a back stay, but it is really just for rake and bend, the mast is secure with just the shrouds and the jibstay (furler).

I'm in the process of modifying the backstay, that will be split at the mast head and the lower ends attached to the catbird seat outer edges. They will be secured with pelican clips and tubular keepers as I have shown previously. Having relooked at the gin pole stay situation, I think they will be pretty easy to setup too. Now if I could mount the gin pole as a bowsprit then stowage would cease to be an issue

Paul

Edited by - on

aeckhart
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Response Posted - 01/12/2007 : 15:14:47

Paul,

Sorry! One of the risks of a C25owner advising a C250 owner. I use an 8 foot piece of 2x4 as a gin pole and lower to, and raise from the stern. The bridal I described works well for me. Perhaps it would be useful in your system design.

I checked out aluminum poles form Charlston Spar. They have a removable sprit - 3.2" diam. x 6 feet long, for $615. I'm considering picking one up for my boat to get the tack of my cruising spinnaker out in front of the bow. Although it's a little short, it may be useful as a gin pole as well as a sprit pole. You would probably pay the same for a good quality spinnaker pole, which may be more useful in your situation. Just some options.

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Arlyn Stewart
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Response Posted - 01/13/2007 : 07:56:27

Paul,

I agree with the discussion that lowering aft is better on the 250 because only the forestay needs a pin removed whereas forward would require all four shroud turnbuckles released, a considerable effort.

The temporary mast raising baby stays allow the use of a mono gin pole with no further stabilizing needed except strapping the gin pole to the base of the mast in some way. As has been mentioned, this method uses the eye in the anchor locker as a secure point for either the B&T or the winch line.

The technique works ok...but has some risk. If one of the baby stays fails, the mast will yield the other direction, the gin pole will role and the mast will fall. Some have experienced this with a pelican hook that wasn't fully locked and popped open.

Also, the length of the mono gin pole is critical in that it has to match the distance from the mast base to the anchor locker eye because when the mast is vertical the gin pole is now horizontal and attachment at the top of the gin pole must be directly over the anchor locker eye.

I do believe an adjusting whisker pole would work ok as a mono gin pole observing a few considerations. A receiver would need constructed for the mast base. This could be a piece of pipe with ID to receive the OD of the whisker pole perhaps a foot long fitted to a saddle that strapped to the mast base. An adjusting pole would also need drilled for a locking pin at the proper length to match the anchor locker eye. The vang tackle could be used (in fact the vang tackle and the mast raising tackle were identical on the early 250s). If one all ready has the two temporary baby stays and a whisker pole, this is the route I'd go.

An alternate to the mono gin pole is a Standing A Frame. It is the most evolved form of mast raising. A standing doesn't require the articulation of a rotating nor is the length critical for the same reason as the mono gin pole.

Because it doesn't articulate, it is much easier to build and the securing scheme to the stanchions bases can be very simple. In the case of the 250, the eyes for the baby stays would make excellent hard points. Another plus is that when the boat is riding smooth...no temporary baby stays are needed to laterally support the mast, the A frame takes care of the lateral stability.

The disadvantage is that two poles are needed rather than one, but in principle two poles will store almost as easy as one. About ten feet is needed so if built of tubular collapsing structure about six feet storage length would be the result but that could be shortened further if using three telescoping pieces.

The good news is that other than a block at the apex, no other tackle is needed as it is very easy to route a line down through a jib track fairlead and to a sheet winch for raising and lowering.

Edited by - on

Ben - FL
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Response Posted - 01/13/2007 : 16:35:26

When I had Desiderata, my C-22, I used to just shoulder the mast to raise or lower. The C-250 is much too heavy for that. Please be careful and do not ever get under the hanging load. Much better to loose it and have it crash through the deck than crush you. You absolutely need a gin pole. The first time I tried lowering my mast on the water I pinned a block to the stem and raised a bridle up the mast with the jib halyard as far as the spreaders. A line was lead from the bridle down to the block at the stem and then to the jib sheet winch. I had a mast crutch positioned in the rudder gudgeons. As the mast came down the angle of attack on the bridle became more and more acute until it lost all its mechanical advantage and the 1/2" line stretched like rubber. Fortunately the mast landed in the crutch (hard.) Now I use an 8' 2x4 with a notch at either end to keep it on the mast and the bridle. I do remove the boom first. You do not want that complication when lowering the mast. Just take it loose at the goose neck and set it aside. You are correct about the gin pole wanting to sway from side to side. If the water is very rough I would not try it. But with smooth waters I have lowered mine in this manner at least three times and then raised it. It works very well and the lowering was controlled. I could even stop the process to straighten out some kinks in the rigging. One problem I did have was the bridle slipped off the sheave of the block and wedged in the bracket. With that amount of stress on the line it was hard to free it up. Be sure your hardware will stand up to the tension.
Good Luck, and as always, should you fail in your mission our secretary will disavow all knowledge of your doings. :-)

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britinusa
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Response Posted - 01/13/2007 : 20:42:14

Thanks Ben, worthy notes.

An 8' 2x4, what on earth else could you use if for? (see my note on multi-functionality)

Glad nothing(noone) was hurt when the rope stretched!

I'm starting to wonder if the gin pole could be kept in position from the mast to the bow all the time, would it act as a tweaker, keeping the jib sheets from catching on anything?
I could hang it on the side of the boom or up front of the mast.

anyone ideas on where to keep it while on the water (sailing

)

Paul

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Ben - FL
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Response Posted - 01/14/2007 : 18:57:35

I am thinking about a two part gin pole that would not be telescopic but rather one piece fitting inside a socket of the other. I don't think a telescopic type would handle the compression from the bridle. But a two part would break down and store in a locker below. I'm thinking along the lines of an 1 1/2" O.D. wood handrail eight feet long and sawn in half with a socket on one end from 1 1/2" I.D. metal fence post long enough to handle the lateral stress. The metal socket could be secured with a set screw or even peened into place.

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Bubba
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Response Posted - 01/14/2007 : 19:51:12

Ben,
It might be a little heavier, but consider 1" galvanized exterior electrical conduit. Home Depot has 10' joints fairly cheap. They come threaded on both ends and include a threaded union. All you have to do is cut them in half. You'll have two 5' poles that can be screwed together. [url="http://mywebpages.comcast.net/frayed-knot/projects/a_frame.htm"]Click here [/url]to see what I did with 'em.

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Arlyn Stewart
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Response Posted - 01/15/2007 : 06:35:52

Dave.... very nice sight and a great idea using the electrical conduit and cutting them in half for easy storage and just screwing them together when using.

Do you see an advantage of the articulating A frame over a standing A frame?

If there is none, it seems to me looking at the picture of the stanchion base, that a standing A frame could be equipped with rubber feet and simply stand in and be lashed into the pocket of the stanchion base and support.

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Bubba
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Response Posted - 01/15/2007 : 10:40:45

Arlyn,
You make a good point. I see no real difference in mechanical advantage. The A-frame's value is when the A-frame is vertical and the mast gets closer to horizontal. So, the articulated version doesn't really add anything. I designed it to simulate the older gin poles that fitted into the mast base.

I considered the idea of using the boom as a gin pole since it has to come off anyway. I have a friend with an old Chrysler 22 that has a fitting that connects the boom to the mast base for lowering. The problem is J=9' and E=11". The boom is probably too long.

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Turk
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Response Posted - 01/15/2007 : 21:51:49

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Arlyn Stewart
 Paul,

Because it doesn't articulate, it is much easier to build and the securing scheme to the stanchions bases can be very simple. In the case of the 250, the eyes for the baby stays would make excellent hard points. Another plus is that when the boat is riding smooth...no temporary baby stays are needed to laterally support the mast, the A frame takes care of the lateral stability.
<hr height="1" noshade id="quote"></blockquote id="quote">

I agree with most of what you say except the idea that the A frame will not require baby stays. Believe me, when I was testing my A frame project, the mast is under great stress forces when it was horizontal and beginning it's trip up. It would appear the A frame should stabilize the lift, but what happens is the mast continually wants to drift to the left or right as it is pulled from a forward direction. I could not get it to stabilize in the center at all. As the pressure comes off as it rises to vertical, the sideways pressure gets less. I had to use baby stays. What could complicate it even more is that as the mast rises and if it drifts to one side or the other, the weight changes and the boat will heel to that side and increase the sideway motion even more. The baby stays are an easy solution to stability and would not add substantially to the cost of the project. I used the "moving" A frame as it was easier to rig the lines, block, and disconnect everything when the mast is up.

Edited by - Turk on 01/15/2007 21:53:28

Arlyn Stewart
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Response Posted - 01/16/2007 : 08:16:17

Turk...I readily accept your insights about what happens when using the A frame on the water and can see that boat movement on the water could sway the mast back and forth or if the boat heels, the mast would go to that side. I've said in the past that using one without lateral stays could only be done with still water but I guess that even the operator movement will have enough effect to create problems.

A mono gin pole must have lateral stays but there have been many reports of those who use an A frame that claimed no lateral stays were needed... I've never used an A frame, have always used a mono gin pole so have no first hand experience.

Having said that, the mast can't fall as it can with a mono gin pole. The tug line is fixed by the A frame to the center of the boat and the mast will always be pulled towards that center as long as the boat is not heeled. If the boat heels, the mast will yield some to that direction and even perhaps then contribute to heeling producing even more mast shift... so I can see where that could be a problem and one that is best prevented by the use of lateral stays.

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Ben - FL
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Response Posted - 01/16/2007 : 15:12:48

Dave & Deb, that is excelent documentation! I believe I'll go that rought when I have time to make one. What's your take on using 1" aluminum conduit which will not rust and saves weight? It might be hard to find but somebody must carry it.

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Bubba
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Response Posted - 01/17/2007 : 19:31:11

Ben,
I have a tall rig and I feel better having the strength of the heavier steel conduit. I think you might have a challenge finding a way to securely connect two pieces of the aluminum conduit. I'm certainly open to suggestions though.

Edited by - on

sweetcraft
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Response Posted - 01/19/2007 : 06:38:21

I have just read through the topic and didn't see mast crutch which is another pole to store. Can you lower the mast all the way to the stern pulpit (I'm a C25 TR sailor)? Do you use the forestay for lowering? I can raise and lower my mast alone but better with help and use the mainsheet blocks and line for the power, a bridle steadies the gin pole, spinaker pole, but I must steady the mast all the way to the mast crutch or up to verticle. I use the jib halyard with a line attached for a safety line to a bow cleat while removing the forestay pin or attaching it. There is sure a lot discussed on this and several ways work well but safety with help from an experienced sailor for the first time sounds best. Take notes and pictures if possible to go over before each effort. I store all the gear to raise and lower in one bag and area so it is always ready.

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britinusa
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Response Posted - 01/19/2007 : 07:52:13

Jim, Good point.
Remembering that my goal is to allow mast lowrering in order to pass under low bridges, so I desire to make the process as simple and stable as possible without having to take down too much stuff.

Our stern mast crutch is removable, it gets mounted on a second pair of pintels to stbd of the rudder. It has a telescopic extension that raises it just above the bimini, so we can put the mast down with the bimini still in place. Also we can leave the crutch in place throughout our trip.

Currently the back stay passes through a hole in the bimini down to the deck on the port side of the boarding ladder walkthrough, however, I'm changing that to dual backstays that connect to the masthead and the outside of the catbird seats which is also outside of the bimini.

All of this means that we would be able to lower the mast to the stern crutch without disconnecting the backstay or lowering the bimini. We would have to detach the boom from the mast and secure it.

So far I'm really leaning to the original concept (in fact, the Nautical Flea market is here this weekend so I'll be looking for the bit-n-pieces.)

Here's my list so far.

Whisker pole suitable for the gin pole, probably at least a 1&1/2"dia (<= 2") aluminum spar. (May have to get spars and fittings to make a telescopic gin pole/whisker pole) It has to be about 8'- when used as the gin pole, but not sure what it should be when used as a whisker pole.
SS Straps for top of gin pole to connect baby stays.
Stainless wire (same dia as original babystays)
SS Thimbles for both ends of babystays.
Stainless Snap hooks for connecting babystays to top end of gin pole and the stanchion shackles
Plastic clips for storing the gin pole on the port side stanchions
While I'm there, hope to get some Sunbrella to make our bimini extension that will go from the front of the bimini forward under the boom (split around the mainsheet).

I'm probably going to get a local shop to manufacture the new backstays as I want Eyes at the top and turnbuckles & shackles at the bottom.

Of course, I want all of this for less than a dollar!

Anyone have comments on the length of the pole when used as a whisker pole? (Assuming that some kind soul will buy me a 135% Jib sooooon!)

Paul.

Edited by - britinusa on 01/19/2007 07:56:28

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