Author Topic: Mast TILTING (not "raising") question  (Read 863 times)

Offline Andy Knoczek

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Mast TILTING (not "raising") question
« on: December 15, 2016, 03:00:21 PM »
OK, I think I did a thorough look-see-search through the archives and can't seem to find a good explanation regarding the mast tabernacle and it's role of handling the stresses during a mast "Tilt" - Let me explain what I am looking for:

I have a CP19 I am wrapping up getting finally off the hard and out of the $200/month marina. I have the opportunity to save said $200 by keeping it at the dock at the house I am renting. The issue is: I only have a one-way into my canal system and it entails going under a 15' clearance bridge. So I would need to (1) Lower (tilt) to an angled height less than 15' (2) KEEP it at that angle while going under without sway (3) hike it back up and attach forestay.

There have been some fine gin pole examples here and I have the one in mind, so I plan to have a 2x4 system through bolted at the tabernacle and using blocks. I will make temp baby stays from the mast 8' off the deck in-line with the mast center.

The above rig I have a good handle on, but have one concern: The tabernacle. Now I have read here a couple thoughts on the thru-bolting of the tabernacle vs. the stock screws into the deck only, the latter breaking away harmlessly in the case of a dismasting. That makes sense. BUT... If I am going to be lowering, holding at angle, and raising, would the tabernacle be strong enough to keep the mast base in check during this process? I have read some had break-away due to deck compromise. My deck is very solid and I can only think that the screws would be in securely. Would this be enough to keep it in place? Or with the setup I have, should I just take my chances, or do a thru-hull 4 bolt system like some of you experienced folks have done? - My main concern is regarding the loosening of the mast-base-tabernacle bolt to let the bolt slide up and down that slot, but due to baby stay tension, it would keep the mast base tight to the tabernacle and instead of traveling up that pivot point, it would lever-effect and tear out the tabernacle... any thoughts? Thanks much!
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Offline Tim Gardner

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Re: Mast TILTING (not "raising") question
« Reply #1 on: December 15, 2016, 04:00:30 PM »
Don't use baby stays, that will tear out the tabernacle.  I used to use a sliding fulcrum.  I built it out of a SS boom gooseneck slide from dwyer, two eight foot aluminum conduit poles flattened a drilled at each end and two sliding cars mounted on my genoa tracks.   I also bolted an eye in the mast groove at the base of the mast about 3" up from the bottom.

I would lower the sail  below the gate, insert the slide, bolt one end on each pole through the eye and the other ends to the cars.  This makes a pretty good truss.  I also attached a block  to the tabernacle through which a line led from the slide eye through the mast base eye and then to my port winch. also I had a lever type disconnect on the forestay.  To lower the mast to the correct height, I made fast the fulcrum by taking slack at the winch, released the forestay,  then slowly allowed the slide to travel up the mast groove, causing the mast to lay aft to the desired point, then made fast the line.  To raise the  mast back to full up position, I just winched her back up, pulling the slide and the fulcrum back down the groove, and reattached the forestay. The tension on the slide line at the base of the mast kept the mast from levering the tabernacle out of the deck

One thing though, you must have a roller reefing gooseneck on your 19 and set the boom 90^ from normal or the boom won't swing far enough up towards the mast to attain a 15" mast height.

Dwyer will make you an extended gooseneck long enough to swing the boom right up against the mast if you want. 

I don't have any pictures of this rig, and because my boat camps out at my dock, I don't use it often.  I built it to go under a 14' bridge.  If I was trailer sailing a lot it would be my one armed mast raising rig.

TG
"The sea is selective, slow at recognition of effort and aptitude, but fast in sinking the unfit"  - Adm Felix Riesenberg.

Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #2 on: December 15, 2016, 04:33:17 PM »
Thanks Tim, but I am having a problem visualizing... you are saying the fulcrum attached to the slide on the mast is the fulcrum point with the mast being unbolted from the tabernacle then tilted back at that slide being the pivot point?
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Offline Wes

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Re: Mast TILTING (not "raising") question
« Reply #3 on: December 15, 2016, 09:24:59 PM »
You know what I would do? Find a slip on the other side of that bridge. Don't care what kind of rig you create, that 19 mast is heavy and unwieldy and it's a challenge for two adults to handle even on the hard. I would not want to do it on the water while underway, every time I went sailing.

On a 16, maybe.

Wes
"Bella", 1988 CP 19/3 #453
Washington, North Carolina

Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #4 on: December 15, 2016, 10:32:44 PM »
I appreciate the sentiment Wes, however... my options are limited, and I would only be taking her out 1 or 2 times per month staying out a whole weekend when I do (Fri eve till Sun eve) - the waters near the bridge are calm and sheltered. Only a tidal swift flow pre-post slack-tide. I just need a system to hold it up on tilt while I go under, I don't have any problems even if I had to remove the boom and sail. I would be motoring another 10 miles to my closest inlet on the east coast (St Augustine). Thanks.
ps - I've seen MacGregors touting this ability/rig on their bigger 26' M and X models... why couldn't it be done on my little CP19?
« Last Edit: December 15, 2016, 10:34:32 PM by Andy Knoczek »
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Offline Potcake boy

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Re: Mast TILTING (not "raising") question
« Reply #5 on: December 16, 2016, 12:24:54 AM »
Andy,

When I had my 19, it came with a gin pole and tackle to raise/lower the mast and didn't require any side stays. I never tried it on the water which can be a bit more challenging. I'll have to admit that TG's method is quite genius and as I visualize it, should work very well. The gear should also be easy to store aboard once you've raised the mast again.

Of course, your other option would be to get a Com Pac cat boat. I think the newer ones with the attached raising system can be operated from the cockpit.
Ron
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Punta Gorda Florida

A mouse around the house - but much hotter on the water

Offline Bob23

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Re: Mast TILTING (not "raising") question
« Reply #6 on: December 16, 2016, 05:04:46 AM »
  Andy, for what it's worth: PeterG (longtime member here and former 23 owner) installed a pretty hefty hinged tabernacle on his 23 before he sold her. I plan to install the same thing on mine.
  Here in NJ, I have a good friend who sails a Bristol 34 and lives upriver to a low bridge which requires him to partially lower the mast every time he sails in the bay near his home. He has a similar hinged tabernacle and has devised a lowering system using a 12 volt winch from Harbor Freight. Although I have not seen it in action, friend Steve explained how it works and he's used it all summer. The winch is mounted on a wood board and is temporally mounted on the foredeck when needed and is operated from the cockpit which allows the operator to also guide the mast into the crutch. I can get some info from him if you'd like.
  Obviously, the mast is much higher and heavier than your Compac 19 mast and he's had no problems. I plan to build the same thing for my 23 as there are some low bridges on waters nearby that I plan to explore.
Cheers!!!! Bob23
 


Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #7 on: December 16, 2016, 09:23:36 AM »
Thanks Bob, sure! Anything you can share would be great. It's funny you bring up the hinged tabernacle because that was going to be my next question of suggestion. I've seen the MacGregor videos showing their system and noticed they have the hinged tabernacle. This would eliminate my fear that sliding/pivoting bolt-thru would lever the tabernacle. Is there a mfg of one that would work with my mast? Thanks!
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Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #8 on: December 16, 2016, 11:18:35 AM »
In a past post, http://cpyoa.geekworkshosting.com/forum/index.php?topic=8376.0 - philb had a nice simple design I was going to try to replicate. Either with the wood, or using metal pole bolted thru to strapping/plate to connect to the thru bolt on the tabernacle-to-mast.
This system makes sense, but would the load on the tabernacle be too great? I would make a mast crutch higher than the deck to lay into. I don't know the history of how often in the past the mast was lowered on my boat, but scoring around the mast bolt slot in the tabernacle shows wear as it was done more than once in the past.


http://http://i1125.photobucket.com/albums/l594/CPYOA/cp19%20lowering%20mast_1.jpg
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Offline Tim Gardner

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Re: Mast TILTING (not "raising") question
« Reply #9 on: December 16, 2016, 11:37:08 AM »
Andy,  for mast fittings and hinges go to : https://www.dwyermast.com

This is the gooseneck slide I used to make the A frame slide up the groove



Hinged mast step:



Here is the car:

from west marine

A Frame:


The advantage of the a frame is it stabilizes the mast side to side without using baby stays

TG
« Last Edit: December 16, 2016, 11:40:09 AM by Tim Gardner »
"The sea is selective, slow at recognition of effort and aptitude, but fast in sinking the unfit"  - Adm Felix Riesenberg.

Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #10 on: December 16, 2016, 11:47:32 AM »
WOW ! Thanks Tim! I was just about to post the question: Would it look like this:

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Offline Tim Gardner

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Re: Mast TILTING (not "raising") question
« Reply #11 on: December 16, 2016, 11:59:01 AM »
Yep - That's about it.   In your case, (since it looks like you do not have a stern rail) if you add a third, shorter leg and a cane rubber, it could also act as a mast crutch when you trailer the boat.  You just lower it all the way down to til the third leg meets the combing then un-pin the hinge, slide the mast forward and rest it on your bow rail.

TG
"The sea is selective, slow at recognition of effort and aptitude, but fast in sinking the unfit"  - Adm Felix Riesenberg.

Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #12 on: December 16, 2016, 12:06:22 PM »
Yeah, she is on the hard while I am renovating. I do not plan to trailer at all since I have a dock where I rent. It will only be tilt, go under, raise, sail! Thanks so much for your time and input! I appreciate it much!
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Offline Andy Knoczek

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Re: Mast TILTING (not "raising") question
« Reply #13 on: December 16, 2016, 01:26:35 PM »
Hi Tim, thanks again! just a couple more details when you can...

1) what diameter pipe do you use?
2) was is the dimension and angle of the flattened ends?
3) if the gooseneck slide track eye is where both flattened ends go thru with a bolt, should the bold be over-tightened?
4) how tight should bolts at the track cars be?
5) how close to the forward end of the tracks would the cars usually go?
6) the gooseneck slide shows both a mast parallel and perpendicular eye, which gets tied and which gets the bolt?
7) in your experience, how hard was it to adapt the hinged mast?
8 ) is the gooseneck slide prone to binding on the way up or down?

I figured I could build the A frame and bolt/sliding hw, then take the mast down while on the hard, install the hinge tabernacle, put it all back together - AND be one step closer to the water. Just a rub-rail and some electrics and I can have her on my dockside to really get her together! Thanks again Tim, your system sounds exactly what I need!

Andy K-
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Offline philb Junkie19

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Re: Mast TILTING (not "raising") question
« Reply #14 on: December 18, 2016, 01:44:20 AM »
Andy,
I agree that Tim's design is much better suited to working with your mast on the water than my gin pole and baby stays. My rig works fine on a trailer. In the water with any of the boat's normal side to side motion, not to mention a power boat's wake, the solid A frame support would limit the mast swaying side to side which you clearly do not want.

The new free standing mast my 19 is keel stepped and made from round aluminum tubing (mostly) and spruce for the top section. This year two of us stepped and unstepped it with a single "stationary" gin pole with rope stays and the boat on the trailer. The pole had to be higher than the center of the mast which mast is stepped through the hatchway and the tall gin pole gets bolted in the original mast step. The stays were cleated aft. going through through blocks on the old jib tracks.  For the stays I used static kermantle rope that I had on hand and which has very low stretch especially under a relatively light load. Getting the pole set was a bit of a challenge and I found that even minimal stretch can allow some unwanted motion. My friend and helper still talks to me and is willing to help again in the spring so I guess it wasn't too bad.

I hadn't been thinking about it but the rig change leaves my original gin pole, pictured above, along with the lower baby stays sitting in the barn. I'm using the block and falls elsewhere and scavenged the eyebolts from the gin pole and maybe a couple of the snaplinks from the stays. I started out to say if any 19 owner wants them but they sound less attractive as I write. Maybe not worth the shipping cost which probably wont be cheap due to its non standard length and the weight.  I just spent $47 Saturday to Fedex a medium sized box to my grandson two states away to guarantee it would gt there before the 25th. Still, if someone does want them let me know.