Boon vang for CD 36

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Jeff Peterson
Posts: 36
Joined: Jan 22nd, '12, 09:23
Location: Cape Dory 36
Jubilee
Galesville, Md.

Boon vang for CD 36

Post by Jeff Peterson »

Hi all

Does anyone have experience using the boom vang directions posted on the CDSOA website under "Where to look...." under Goups and publications... under manuals... basically adding bails to boom and mast and using block and tackle? Eg any issues will integrity of mast or boom? Are the recommended bails really strong enough?

Also, any suggestions on the appropriate working load or ratio or line size? Debating whether to rely on cam cleat at the block or bring line to cockpit.

Many thanks for any input.
Vincent
Posts: 146
Joined: Mar 2nd, '13, 20:10

Re: Boon vang for CD 36

Post by Vincent »

I have a 33. I made a strap from a heavy duty nylon tow strap, the kind with 2 large galcanized hooks. I use a 4 part Garhauer handy billy, doouble block top and bottom. Hooks to a well backed eye in the deck and back to the cockpit winch. Easy peasy. On a gybe, I just let it run. when settled down, I go forward and take the bottom across. I guess eventually I will get a second and keep them attached. i guess I should say, the strap wraps around my loose footed boom.
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jbenagh
Posts: 868
Joined: Sep 15th, '07, 21:02
Location: CD30 "Christine C"
Salem, MA

Re: Boon vang for CD 36

Post by jbenagh »

I followed the directions exactly for my CD30. It worked very well. I thought there were line sizes listed. There is a calculator somewhere on the web, maybe Harken, that estimates loads for various rigging components based on sail area and wind speed. FWIW I believe I used 5/16. I think I have a 3:1 purchase (although it could be 4:1). I used the Ronstan fiddle block with the built in cam cleat. I have to go a little forward to release it but have not gotten around to a deck mounter fairlead and cleat.

Jeff
Maine_Buzzard
Posts: 506
Joined: Dec 22nd, '10, 21:15
Location: Feet Dry, Olympia, WA

Re: Boon vang for CD 36

Post by Maine_Buzzard »

Installed using a 3/8" bolt in the mast and and a 5/16" in the boom, used two ebay bails-

http://www.ebay.com/itm/S-S-Boom-Bail-L ... nQ&vxp=mtr

I had a Harken 4:1 rig from somewhere and removed the camcleat. I ran it to a new deck block aft of the dorade and then to the unused staysail winch/cleat.

5/16" line and snap shackles at both ends, so rigging it as a preventer is easy.

Works great, loads are balanced with the mainsheet and traveler. No concerns with mast or boom integrity, the holes are centerline and small. 5/16" bolts would be plenty large enough.
+1 on bringing it back to the cockpit. If I brought the staysail back into play, I'd add a third camcleat between the existing ones.

Image

It's the white/green line outboard and does help to control twist and boom lift. The extra length is for when used as a preventer. I extract it from the padeye block and tie off to a cleat as needed.

This is not Nuclear Engineering- Mount it where you have room and can make it fit, keeping it close to 45 degrees and as long as practical. I'll suggest 3/8" line for a 36 and if you want to use it as a preventer, add D rings to the aft lower shroud clevis pins (at the bottom) and not use the 1/8" stainless loops that are lightly attached to the stanchion's bases.

http://www.uscargocontrol.com/Rigging-S ... less-Steel

Good project!
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jbenagh
Posts: 868
Joined: Sep 15th, '07, 21:02
Location: CD30 "Christine C"
Salem, MA

Re: Boon vang for CD 36

Post by jbenagh »

I looked up what I did for my CD30:

3/8in line, Sampson LS, 35 feet
RF51530 Ronstan fiddle block with cleat
RF51500 Ronstan fiddle block
4:1 purchase

I spliced the eye myself

Jeff
John Stone
Posts: 3623
Joined: Oct 6th, '08, 07:30
Location: S/V Far Reach: CD 36 #61 www.farreachvoayges.net www.farreachvoyages.com

Re: Boon vang for CD 36

Post by John Stone »

Jeff,
I'm not sure I can offer much since I replaced the rig-rite spar and boom with ones made by Sparcraft. My boat came with a rigid vang which I did not incorporate into the new rig because to do so would mean I would not have been able to stow our hard dinghy on the cabin top which is the best place for a hard dinghy. Hall, that makes one of the popular rigid vangs probably has fittings for the rig-rite spars as does rig-rite itself. I'd talk with them. On my original rig there were no bails but instead there was a special fitting run in the groove under the boom and bolted to a backing plate in the boom itself. There was one on the mast, just above the cabin top as well. Make sure you have a plan for dinghy storage before you decide on a solution for your vang.

There are tremendous loads exerted on the boom especially when it is located on the forward end of the boom due to the force created by such a long lever arm. Though the rig-rite boom is very strongly made I am not a fan of bails connected by bolting through the boom side to side. All the load is on one area of the boom. Broken booms are often the result of the forces caused by point loading.

Since I did not initially know where I wanted to rig the attachment point on the boom for my vang I started off with a strap run round the boom connect to a block and tackle. I used that approach for local sea trials and for my offshore trip to the West Indies. But I knew all along I wanted a more permanent system that would reduce point loading.

While in the islands, I installed an 18" long x 1" x 1/12" T 6061 aluminum bar inside the boom to which I drilled and tapped for the bottom of the boom mounted padeye/bail. I used the same approach for my mainsheet secured to a 4.5' long aluminum bar in the boom. Here is a link that documents how we reinforced the boom for the mainsheet but I used the same approach for the vang. Scroll to near the bottom under "installing mainsheet traveler." http://www.farreachvoyages.com/projects ... sails.html

I run the vang from the boom located over half way back from the goose neck to the bulwarks. If I did not have a bulwark I would use a system similar to the one advocated by Hal Roth and install a through bolted pad eye on the side deck on both side of the boat and vang from the boom to the pad eyes. This approach allows the vang to also serve as a preventer. A preventer should always be used with sailing downwind to protect the crew and also the rig from injury or damage in case of an unplanned gybe. With two vangs, one rigged on each side, you have complete control over the boom throughout a gybe.

Currently I use a block and tackle (shafer-fiddle blocks) with integral cam cleat. I plan to change it to eliminate the cam cleat on the fiddle block and instead route the running line aft to cam cleats mounted on the aft end of the cabin top on each side of the companion way. The reason is that because the vang is mounted to the deck edge it also serves as a preventer and in the case of a knock down or if the boat was forced into a gybe through say a self steering wind vane failure or some crazy rouge wave I could quickly release the vange immediately from the cockpit--the lee rail could be buried under water. I use 1/2" double braid line.

In the photo below, taken on my single handed trip home last May, I have two vangs rigged to a single bail.
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Last edited by John Stone on Mar 1st, '17, 10:33, edited 1 time in total.
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mgphl52
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Location: s/v KAYLA CD 28 #318
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Re: Boon vang for CD 36

Post by mgphl52 »

From what I've read, a 45 degree angle is incorrect. Most recommendations are for distance between mast & boom bail to twice the height between boom and base connection.
-michael & Toni CDSOA #789
s/v KAYLA CD28 #318
2012 FLSTC Heritage Classic
Niceville FL
+30° 30' 24.60", -86° 26' 32.10"
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John Stone
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Joined: Oct 6th, '08, 07:30
Location: S/V Far Reach: CD 36 #61 www.farreachvoayges.net www.farreachvoyages.com

Re: Boon vang for CD 36

Post by John Stone »

MGPH, that sounds about right.
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