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Catalina/Capri 25/250 Sailor's Forums

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Still refining new gin pole

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OJ
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4382 Posts

Initially Posted - 10/26/2013 : 17:32:29

This is the second time we've lowered the mast using the new gin pole. Tomorrow we raise the mast again at the canvas maker.

1989 C25 TR/WK, #5822
1973 McVay Minuet 19
1975 Jester 12
1981 C25 SR/SK, #2428
1981 C22 SR/SK,
Tanzer 16
Sunfish

"There is nothing, absolutely nothing half so much worth doing as simply messing about in boats." Kenneth Grahame

Edited by - OJ on 10/28/2013 18:33:41

TCurran
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Response Posted - 10/27/2013 : 04:25:18

OJ, do you have a close up of the gin pole mast joint and how you have the front line mounted at the trailer(sorry if I missed an earlier post and picture). From that pic, it looks like a great set up.

Are you wearing ear muffs?

Edited by - TCurran on 10/27/2013 04:27:36

OJ
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Response Posted - 10/27/2013 : 05:13:49

Hi Tom and thanks for the interest. This is the first photo of the gin pole. Off to the canvas maker this morning - will take close-up pictures of the components - unless we drop the mast!

FWIW, this is a tall rig, so the mast is 2' longer and a larger and thicker extrusion. A son of a son-of-a-gun to raise.

Headband.

Edited by - OJ on 10/27/2013 05:16:55

TakeFive
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Response Posted - 10/27/2013 : 06:14:16

Do you have an A-frame or baby stays to keep the mast in column? I'd recommend baby stays on the gin pole also.

Edited by - on

TCurran
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Response Posted - 10/27/2013 : 07:07:43

we have a guy in the Marina with a 26' hunter, I watch him raise and lower his mast by himself with no real effort using the factory gin pole (pretty sure he has baby stays to keep the mast straight). He does this with even less effort than Davy J's a-frame system (although the gin pole will not work for Davy J because he has to raise and lower underway). I've also used the boom as a gin pole lowering forward like Chuck Shaw does, but it still wasn't as easy as the 26 hunter.

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pastmember
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Response Posted - 10/27/2013 : 07:33:49

Hunters have SS poles affixed permanently to the mast in a lower shroud position that act as an A frame when using their mast raising system. The Hunter really is a trailerable boat because if its stock mast raising system and water ballast and the Catalina is merely a transportable boat.

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dmpilc
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Response Posted - 10/27/2013 : 07:58:57

Mine was a TR also. I recommend that you NOT do this by yourself with a gin pole. Make an A-frame a la DavyJ. I did and it worked very well. It's also very easy to make.

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pastmember
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Response Posted - 10/27/2013 : 08:43:55

Gin pole = mechanical advantage

A frame = lateral stability

They seem a symbiotic pair rather than mutually exclusive.

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Davy J
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Response Posted - 10/27/2013 : 12:16:43

<blockquote id="quote">quote:<hr height="1" noshade id="quote">They seem a symbiotic pair rather than mutually exclusive.
<hr height="1" noshade id="quote"></blockquote id="quote">
Gin pole = mechanical advantage

A frame = lateral stability + mechanical advantage

Both have one, one has both......

The a-frame with the lower shrouds attached to the frame means the mechanical advantage has lateral stability and so does the mast.

However, there is no right or wrong way, just the safe way.......
It looks like OJ has capable helpers.

I like Lee Panza's set-up from this thread,

http://www.catalina-capri-25s.org/forum/topic.asp?TOPIC_ID=27424& SearchTerms=mast

However I'm just too lazy to change to it.....

Edited by - Davy J on 10/27/2013 12:35:07

TakeFive
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Response Posted - 10/27/2013 : 21:14:46

Seriously, you need to make sure you have some lateral support to keep the mast in column. Without it you might raise/lower with no problem several times, but at some point you could get a breeze, or a sideways weight shift, and that mast could torque right off the tabernacle.

I use ratchet straps as baby stays. Fortunately, the C250 has stanchions and bails at that are perfectly located. From what I've seen, on a C25 you'll need to modify something for an attachment point.
I think that's why most people use an A-frame arrangement with that boat.
<center>

</center>

Edited by - on

redeye
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Response Posted - 10/28/2013 : 03:53:32

<< most people use an A-frame >>

Yepper... I usta drop mine forward with lines to the boom to keep it in line and that still made me nervous. Lots of movement and tension side to side. Went with an a frame also.

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OJ
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Response Posted - 10/28/2013 : 16:56:12

Even with a 125" gin pole and raising the aft end of the mast, it is still very difficult to start raising with just the block and tackle - we have to push the mast up some ways before the block and tackle take over. Perhaps too much friction is being created by having the lines come past the anchor roller - down to the trailer winch.

Gin pole saddle - note T-handle pin in place of mast bolt

Edited by - OJ on 10/28/2013 18:38:56

TCurran
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Response Posted - 10/29/2013 : 02:56:05

OJ, thanks for the close-ups.

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britinusa
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Response Posted - 10/29/2013 : 03:39:17

Dejavu!

Impressed by that hefty well made gin pole saddle! Very nice!

<center>[url="https://www.catalina-capri-25s.net/cgi-local/MBR_gallery.cgi?Album+1000+66"]

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OJ
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Response Posted - 10/29/2013 : 16:26:13

Yes, I am waiting for someone to quip "Jeez! what overkill! why did you use such heavy materials?!"

My reply "cuz when someone makes a mistake, the gin pole won't fail!"

Edited by - OJ on 10/29/2013 16:26:53

OJ
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Response Posted - 10/29/2013 : 16:32:02

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by TakeFive
 Seriously, you need to make sure you have some lateral support to keep the mast in column. Without it you might raise/lower with no problem several times, but at some point you could get a breeze, or a sideways weight shift, and that mast could torque right off the tabernacle.

I use ratchet straps as baby stays. Fortunately, the C250 has stanchions and bails at that are perfectly located. From what I've seen, on a C25 you'll need to modify something for an attachment point.
I think that's why most people use an A-frame arrangement with that boat.
<hr height="1" noshade id="quote"></blockquote id="quote">

I sincerely appreciate the input Rick. I can see the A-frame adding some lateral support - but not enough to forego additional hardware (or an extra set of hands.) I get the general concept of baby-stays, but I don't get how they maintain tension as you raise/lower the mast.

'splain please Lucy . . .

Edited by - OJ on 10/29/2013 16:48:58

OJ
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Response Posted - 10/29/2013 : 16:39:22

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by britinusa
 Dejavu!

Impressed by that hefty well made gin pole saddle! Very nice!

<center>[url="https://www.catalina-capri-25s.net/cgi-local/MBR_gallery.cgi?Album+1000+66"]

Mast Raising Concept[/url]
Following the interesting thread in the forum about Mast Raising / Really! Some of the ideas posted there rekindled the concept banging around inside my head for the past few years. Finally started to make sense of it. </center>

Paul
<hr height="1" noshade id="quote"></blockquote id="quote">Thanks for sharing the above Paul. I had ideas rolling around in my cranium for months. I even made cardboard mock-ups which I will post pix of someday.

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TakeFive
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Response Posted - 10/29/2013 : 19:12:16

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by OJ
 ...I can see the A-frame adding some lateral support - but not enough to forego additional hardware (or an extra set of hands.) I get the general concept of baby-stays, but I don't get how they maintain tension as you raise/lower the mast.

'splain please Lucy . . .

<hr height="1" noshade id="quote"></blockquote id="quote">
I am not familiar enough with the A-frames to comment, so I won't.

The C250 has bails welded onto the base of the cabintop stanchions that align almost perfectly with the mast bolt, so they're a perfect place to attach the bottoms of the baby stays (see my picture above). The baby stays keep the mast in column. I don't know how to say it, aside from pointing out that it's a lot easier to keep mast in column than it is to get it back in column once it falls out of column. Perhaps there's no acceptable place to attach baby stays on your boat, and an extra pair of hands is the only way to do it.

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britinusa
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Response Posted - 10/29/2013 : 19:30:05

I have been studying Carbon Fiber layup. I might 'reinforce' my PVC saddle with Carbon fiber and see how it goes.

Paul

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Davy J
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Response Posted - 10/30/2013 : 05:23:45

<blockquote id="quote">quote:<hr height="1" noshade id="quote">I can see the A-frame adding some lateral support - but not enough to forego additional hardware (or an extra set of hands.)<hr height="1" noshade id="quote"></blockquote id="quote">
I'm not sure I understand, but I'll make a comment. First, if you only raise and lower your mast a few times a year, and you have the helpers, your rig should work fine.

The a-frame has "side to side" stability, it cannot "lean" to one side or the other. Even if the mast sways to one side or the other.

The gin pole "may" lean over, especially if the mast were to swing wildly to one side. Because the gin pole is essentially attached to the mast, if the mast twists, and swings, it will also attempt to twist the gin pole.

Because the a-frame is not connected to the mast, and has two connection points, it isn't as influenced by what the mast is doing.

Well, I hope that is as clear as mud.......

Edited by - on

OJ
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Response Posted - 10/30/2013 : 15:29:31

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Davy J
 <blockquote id="quote">quote:<hr height="1" noshade id="quote">I can see the A-frame adding some lateral support - but not enough to forego additional hardware (or an extra set of hands.)<hr height="1" noshade id="quote"></blockquote id="quote">
I'm not sure I understand, but I'll make a comment. First, if you only raise and lower your mast a few times a year, and you have the helpers, your rig should work fine.

The a-frame has "side to side" stability, it cannot "lean" to one side or the other. Even if the mast sways to one side or the other.

The gin pole "may" lean over, especially if the mast were to swing wildly to one side. Because the gin pole is essentially attached to the mast, if the mast twists, and swings, it will also attempt to twist the gin pole.

Because the a-frame is not connected to the mast, and has two connection points, it isn't as influenced by what the mast is doing.

Well, I hope that is as clear as mud.......

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

Alle ist klar!

Edited by - OJ on 10/30/2013 17:33:05

OJ
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Response Posted - 10/30/2013 : 17:34:32

</center>
<hr height="1" noshade id="quote"></blockquote id="quote">Rick, where are you attaching the straps to your mast?

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TakeFive
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Response Posted - 10/30/2013 : 17:37:33

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by OJ
 Rick, where are you attaching the straps to your mast?
<hr height="1" noshade id="quote"></blockquote id="quote">
The C250 mast has a couple of holes to attaching baby stays. They are about 6.5' up on each side. Your mast may not have these, so now that I think of it, that might not be an option for you.

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TakeFive
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Response Posted - 11/16/2013 : 20:49:24

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by OJ
 Even with a 125" gin pole and raising the aft end of the mast, it is still very difficult to start raising with just the block and tackle - we have to push the mast up some ways before the block and tackle take over. Perhaps too much friction is being created by having the lines come past the anchor roller - down to the trailer winch...
<hr height="1" noshade id="quote"></blockquote id="quote">
I lowered my mast today, so went back and re-read this thread. I had forgotten at the time to comment on this statement that you made.

I suspect that your difficulty raising at the beginning has more to do with static forces, and less to do with dynamic friction. I did a lot of vector calculations when I designed my gin pole, to make sure all the lines, winch strap, winch mechanism, baby stays, etc. were rated to hold the tension they were going to see. As the mast becomes more horizontal, those forces go up a lot.

Think of it this way: When the mast is vertical, its entire weight is on the mast step (that's why you have a compression post). When the mast is horizontal, almost zero weight is on the mast step, and the entire weight is borne by the tension of your gin pole rig. The angles of tension are not all that favorable, which can make the tension much greater than the actual weight of the mast. (As you suggest, this is why you want the gin pole as long as possible without interfering with the bow pulpit.) The guy in the cockpit pushing up on the mast has a better angle to apply the upward force, so that takes a lot of the burden off your block and tackle.

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britinusa
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Response Posted - 11/17/2013 : 08:50:45

the Turning Moment shifts as the mast position changes.

When the gin pole is horizontal, most the force from the winch is at right angles to the gin pole.

When the gin pole is vertical, less than half the force is at right angles to the gin pole.

So when pole is horizontal, easy. When pole is vertical - hard!

JMTPW

Paul

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OJ
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Response Posted - 11/17/2013 : 16:55:35

I can't find my calculation but using a 125" gin pole, the amount of force required to lift our 30' mast from horizontal exceeds 300 lbs.

We were also using a 6:1 block and tackle and discovered there is a lot of friction. We had to push on the mast until it was over 1/3 of the way down before it would free-fall.

We're probably going to use the old 4:1 mainsheet block and tackle hereon out.

Edited by - OJ on 11/17/2013 16:58:52

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