Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
I finally had a little extra cash and ordered my boom vang.
It came with no directions. It was easy to see from our association forum how to connect the bail to the mast step.
However on the boom they sent me a Boom Hound and a bail. In reading I think the bail gets higher ratings.
How do you go about spacing and attaching the bail. I read some people talking about a 45 degree angle but I would think I would want to get it out a little further on the boom.
Any help on the install. PS on the boom hound there is a place for the through bolt and 4 other holes , would you want to put that many holes in the boom.
Putting it farther out on the boom increases the horizontal force and decreases the vertical, sail shaping force. 45º is the compromise that delivers half of the applied force to sail shaping and half wasted compressing the boom to the mast while still being far enough out on the boom, a lever with its fulcrum at the boom, to be reasonably efficient. I'm just going with tradition and not doing the calculation for mechanical advantage vs force distribution. It isn't difficult, but I'm lazy.
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
How are you supposed install the boom on the mast. One hole through the center of the boom?
How about the Boom vang hound. It sounds like the hound was an old approach and abandoned. Just want to be sure I put the bail on the boom the right way. I understand how to add one to mast plate. I actually already have one there.
I've seen the boom vang attached to the boom with a boom vang hound and with a bail. Personally, I think the hound is preferable to the bail, because it spreads the load through all the attachment screws instead of just one, but I never heard of a boom failing when a bail was used, so I'd say it's your choice. As I recall, the bails that I have seen were attached to the boom with a bolt through the center of the boom.
Steve Milby J/24 "Captiva Wind" previously C&C 35, Cal 25, C25 TR/FK, C22 Past Commodore
Wow! Is there really that much force on the boom vang that you have to spread it using four screws? I just added a pretty simple boom vang consisting of a piece of 1/2" nylon line tied between a hefty fairlead I mounted about 24" out along the boom from the gooseneck and a cleat that's in the mast track just above the tabernacle. I usually use this mast cleat as a boom downhaul and Cunningham too. I tied a loop on the end of the line with a bowline, then looped the line through the cleat and put a truckers hitch in the bight of the line to get some mechanical advantage. Works setup flawlessly! I'll try and get a photo. I've not seen any strain in the fair lead or the machine screws I tapped into the boom.
[edit] Oh, and by the way, according to my highschool geometry teacher, Mr. K, a 45° angle will result in 70% of the force of a straight vertical. COS(45°) = 1/ squareroot (2)
About 6 weeks ago a boat snapped it's boom into two pieces as it did a hard gybe around a mark a few feet from my boat. It broke at the vang. In strong wind, many people vang the mainsail down hard to flatten the sail. That pulls the midsection of the boom down, out of column. A hard gybe can buckle the thin aluminum tube. That's one of the advantages of end boom sheeting, like the C25. You can flatten the sail hard with the mainsheet without pulling the midsection of the boom out of column. With end boom sheeting, you don't need to set the boom vang hard when sailing to windward.
Steve Milby J/24 "Captiva Wind" previously C&C 35, Cal 25, C25 TR/FK, C22 Past Commodore
So I won't be sailing in strong winds with it really tight, so the bail looks less intrusive to the boom. I read that someone just tied a line around with like a loggers hitch or lashing. No drilling. Has anyone heard of this or have a knot pattern to try. I might try this first. Lash firstvdrill later
Thanks, I think the photo will be,helpful.. Seems like the bail would be ok as well,with the light force I think I would be applying. In strong winds I reef and head home :)
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quote:Originally posted by Voyager
Wow! Is there really that much force on the boom vang that you have to spread it using four screws? I just added a pretty simple boom vang consisting of a piece of 1/2" nylon line tied between a hefty fairlead I mounted about 24" out along the boom from the gooseneck and a cleat that's in the mast track just above the tabernacle. I usually use this mast cleat as a boom downhaul and Cunningham too. I tied a loop on the end of the line with a bowline, then looped the line through the cleat and put a truckers hitch in the bight of the line to get some mechanical advantage. Works setup flawlessly! I'll try and get a photo. I've not seen any strain in the fair lead or the machine screws I tapped into the boom.
[edit] Oh, and by the way, according to my highschool geometry teacher, Mr. K, a 45° angle will result in 70% of the force of a straight vertical. COS(45°) = 1/ squareroot (2)
I'd prefer a bail bolted through the middle of the boom's cross-section over what Bruce describes--tapping the aluminum for machine screws that the vang will be pulling downward(?) The one possible advantage to Bruce's attachment is that in the unexpected jibe Steve describes, which momentarily leaves the mainsheet slack and all of the leveraged force against the vang, the fairlead will probably rip off the boom before the boom breaks...
Things work "flawlessly" until Murphy catches up with you.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
1) An internal multi-part outhaul would require the interior of the boom to be clear; a hound with 1/8" long machine screws is better than a bail in this case.
2) If a bail is used on the boom, with a through-bolt from one side to the other, use a locking nut so it isn't necessary to tighten the bail against the boom. Without a compression tube around the bolt inside the boom extrusion it won't be possible to tighten a single conventional nut enough to prevent loosening (the sides of the boom will be deflected inward, also weakening the boom at that point.
3) If the boom can be raised & lowered on a sliding gooseneck, the connections at both ends need to move as the geometry is changed. Bails need to swivel around their bolts, so locking nuts are again important for this reason.
4) If a hound is used at the base of the mast, the connection for the vang needs to swivel as the boom moves to either side. The eyes of a shackle of sufficient size probably won't fit through the hole in the hound, but putting the pin through the hole will impose an additional bending force on the hound when the boom is far over. A locking carabiner is a better choice.
5) With a pop-top, using snap-shackles at both ends of the vang assembly allows it to be temporarily switched to help raise the top. Reconnect it between an eye-strap attached to the front of the top and a connector on the gooseneck (the sliding gooseneck has a hole in the bottom for a downhaul, so a shackle in that hole can accommodate this as well, but I'm sure something could be rigged-up to a fixed gooseneck). If the vang is not lead back to the cockpit, having it easily removable also provides you with a short but powerful come-along that could come in handy.
Just some ideas to consider. Hope this is helpful.
The trouble with a destination - any destination, really - is that it interrupts The Journey.
Lee Panza SR/SK #2134 San Francisco Bay (Brisbane, CA)
My boat didn't have a vang when I bought her and I have sense installed one. If you choose to go with a bail, then as mentioned above you really should have a compression tube around the bail bolt on the inside of the boom. Thereby preventing boom collapse in case of accidental over tightening durring the install. And yes, it would certainly interfere with an internal out-haul. I chose a well made and sturdy hound made by Garhauer. But I decided to mount it with rivets rather than threaded screws. It has been working fine and I have no complaints with it. Also. I agree 45 degrees. Best of luck with your choice.
OK went out there today and decide to wait until I take the mast down in Nov. Im not sure how to get the lower bail on with current set up.
I have a mast plate but the bail does not fit around it the bail is just wide enough for the mast.
I dont really want to give up leverage on the down haul and mount it above the mast plate. Could I just buy a slightly wider bail and use the same mast bolt that is there so I dont have to drill the mast?
Or can I just drill the mast plate and bolt the bail to it?
PS I built the A frame for dropping the mast to day not a tough job. Need to work in the ends that attach to the Shrouds next.
Hmm, Possibly found another difference on what Catalina installed on different years. My 87 has a plate with 2 bails for attaching the boom vang and blocks like this.
I should have said that they are used together if you were to need more attachment points for turning blocks. My bad. Anyway I just wanted to show other options.
Scott-"IMPULSE"87'C25/SR/WK/Din.#5688 Sailing out of Glen Cove,L.I Sound
Yes, the top picture there is the mast step or "tabernacle" and the bottom picture is the "mast base plate" for blocks to lead lines to the cockpit. The tabernacle goes on top of the base plate. I needed some new holes in CD's plate to match up to my original tabernacle (which didn't have the bails). It looks like CD added holes to the plate to try to solve that problem.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
quote:Oh, and by the way, according to my highschool geometry teacher, Mr. K, a 45° angle will result in 70% of the force of a straight vertical.
The simple sum of vector forces when the angle of application is not considered will exceed the actual applied force. The sine and cosine of 45º are equal. 100 pounds of force applied at a 45º vectors to 70# vertical and 70# horizontal.
edit: Multiplying the vectored forces by the appropriate angle functions and summing will result in 100 # of applied force, as you would expect since we're using the same values.
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.