Boom Question

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tartansailor
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Location: CD25, Renaissance, Milton, DE

Boom Question

Post by tartansailor »

Greetings All,
My present 2&3/4" X 2" X 11' 7" boom is too short for the planned
block & tackle I wish to add for a more refined foot tension adjustment.
There is 16" from the end of the boom to the back stay.
A 12' 3" to 12' 6" boom is desired.
Does anyone know if there is a commercially available "plug" I could
fasten inside to extend the length?
Or anyone have a boom to sell?
Thanks in advance for any consideration.
Richard
Viam Inveniam Aut Faciam
John Stone
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Re: Boom Question

Post by John Stone »

Richard, I don't understand what you are doing or why. Can you provide more information and maybe a drawing? I'm sure there is a way to elegantly meet your requirement without jury rigging or modifying the boom.
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mgphl52
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Re: Boom Question

Post by mgphl52 »

I agree with John. I currently have 4-to-1 purchase on my outhaul with a pair of Harken bullet doubles. I also had the same rig on my prior CD25. May be the foot of your main has stretched too much? Also, both of mains were loose-foot and full-batten.
-michael & Toni CDSOA #789
s/v KAYLA CD28 #318
2012 FLSTC Heritage Classic
Niceville FL
+30° 30' 24.60", -86° 26' 32.10"
"Just because it worked, doesn't mean it works." -me
No shirt + No shorts = No problem!
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tartansailor
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Re: Boom Question

Post by tartansailor »

Hi John, Mike,
Thanks for the input.
It's a brand new 6 oz. loose foot main made to factory specs.
There is only 4" from the sail grommet to boom attachment point.
The side of the boom has a slider for reefing. No room there.
I'm wondering if I have a shortened boom? given the 16" space.
Any Cape Dory 25 sailors willing to tell us their boom length?
Richard
Viam Inveniam Aut Faciam
John Stone
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Re: Boom Question

Post by John Stone »

Hi Richard
That's got to be agrivating. How does the original main measure? Four inches should fit. How do you have it rigged? The slide that holds the clew to the boom is affixed to the clew grommet with a sewn web strap. My outback is made of dyneema and I tie it directly to the clew grommet. Also, you are not going to have the out haul drum tight . . . good sail shape is the driver but a couple of inches is the general rule. Can you send a picture of how you have it rigged.

The gap between the end of the boom and the backstay is critical. Though it would unlikely happen, the basic rule for rig design is the boom, if angle up to 45 degrees, should not be able to strike the back stay. During an unplanned crash gybe if the boom does not have a vang the boom can lift dramatically (called a jack knife) and hit the back-stay. Very bad. So, making the boom longer is not a good option in most instances.

Attached is a picture of my out haul on our inaugural sail. The dyneema out haul is a little long (I trimmed it shorter later, but it illustrates the attachment method I described.
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mgphl52
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Re: Boom Question

Post by mgphl52 »

tartansailor wrote:Hi John, Mike,
Thanks for the input.
It's a brand new 6 oz. loose foot main made to factory specs.
There is only 4" from the sail grommet to boom attachment point.
The side of the boom has a slider for reefing. No room there.
I'm wondering if I have a shortened boom? given the 16" space.
Any Cape Dory 25 sailors willing to tell us their boom length?
Richard
I wish I could send you a picture, but Brigitta's been gone since 2002. She was relocated to Jacksonville FL.
That just happens to be where I started my love affair with Cape Dory yachts!
Special 'Thanks' to Barbara Williams who ran Amity Anchorage in Switzerland FL and was the local Cape Dory dealer!!!
-michael & Toni CDSOA #789
s/v KAYLA CD28 #318
2012 FLSTC Heritage Classic
Niceville FL
+30° 30' 24.60", -86° 26' 32.10"
"Just because it worked, doesn't mean it works." -me
No shirt + No shorts = No problem!
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tartansailor
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Location: CD25, Renaissance, Milton, DE

Re: Boom Question

Post by tartansailor »

[quote="John Stone"]Hi Richard

The gap between the end of the boom and the backstay is critical. Though it would unlikely happen, the basic rule for rig design is the ,boom if angle up to 45 degrees, should not be able to strike the back stay. During an unplanned crash gybe if the boom does not have a vang the boom can lift dramatically (called a jack knife) and hit the back-stay. Very bad. So, making the boom longer is not a good option in most instances.

Hi John,
Now that's a meaningful caution.!
Sincere thanks for showing us the light.
Yes, we have a serious vang, but I need to raise my boom and see where we're at.
We need to come up with plan B. Internal outhaul.
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John Stone
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Re: Boom Question

Post by John Stone »

I removed the mainsail from the boom of the Far Reach a couple days ago as part of our preparation for hurricane Mathew. I snapped this picture of how the clew is rigged. It does not take much room.
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Andy Denmark
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Re: Boom Question

Post by Andy Denmark »

Richard,

There's plenty of room for a 4:1 outhaul on your stock Cape Dory boom. If I were closer to my boat (3200 miles away) I'd get a quick picture and send it.

Your problem, as I see it, is two systems in conflict at the concept level. The "adjustable reef track" at the end of your boom is the problem as it takes up the space where the "side" portion of the multi-purchase outhaul system needs to go.

The concept level difficulty is this. You have adjustability hardware on the aft reef point where adjustability is unnecessary. A reef point's position never needs adjustment ... it's either full on or full off. That position is determined by the reef cringle placement on your mainsail and that position never changes. On the outhaul system, its position changes continually, especially on a loose footed sail. The hardware for this adjustment needs room to mount and that's right where the "reefpoint adjustment track" is located.

The solution is simple; take off the reef track (a consignment store is where it rightfully belongs) and get your sailmaker to show you where to put a cheek block and opposite-side eyestrap in the proper reef point position for your new sail. If the holes where the track was mounted bother you then stick a pop rivet in them. Booms are made of aluminum to make placement of hardware for vangs, topping lifts, reefing gear, luff tensioners, etc, easy to change.

John's boom on Far Reach has a non-standard (i.e., not Cape Dory) aft end. His system is great with the 4:1 (or more) tackle located somewhere else. Your "standard" Cape Dory boom end is totally different from that on Far Reach. Both systems work fine ... they're simply different.

FWIW, my CD-27 can be easily rigged for 6:1 on the outhaul, not for increased power but for more finite control of foot tension, a critical adjustment for sail shape with a loose-footed mainsail. There's plenty of room for even that using Harken mini blocks (I only used the 6:1 for racing which I no longer do).

Hope this helps. BTW, you'll love that loose footed main!

Andy
s/v Rhiannon

"In order to be old and wise, one first must have been young and stupid ...
John Stone
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Re: Boom Question

Post by John Stone »

Well I'm confused. Is the question about the outhaul or the reefing system? The outhaul on the Far Reach's new boom is the same as on the original boom. I thought the question was the boom length did not leave enough room for outhaul to work on new sail with perhaps too long a foot. Reefing set up is different issue. A longer boom has nothing to do with reefing. Did I miss something?
Andy Denmark
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Re: Boom Question

Post by Andy Denmark »

John,

Didn't mean to confuse you but I probably misspoke. Your 36 has a different boom end than Dick's. Most early Cape Dories had totally external hardware at the end of their booms, i.e., no sheaves at the end like your boom like Far Reach. I should have stated "earlier" rather than "non-standard," in my description. Earlier Cape Dories came from the factory with NO outhaul hardware except a piece of line and a "D" shackle (simple 1:1 purchase).

When you are next in Oriental to see Mark & LuAnn at Innerbanks go around the corner to Sea Harbour Marina and look at my boat, Rhiannon. She's the first one to the left as you go out the main dock (Slip A-1). Take a look at my boom and you'll see exactly how the older Cape Dories were fitted out.

You can clearly see that adding that extra track to "adjust" a fixed position reef point interferes with the placement of a cheek block that's essential for the 4:1 outhaul system.

I was the Cape Dory dealer in Oriental for 15 or so years and put my outhaul system on almost every one of their boats I sold.

Hope this clarifies things.
s/v Rhiannon

"In order to be old and wise, one first must have been young and stupid ...
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tartansailor
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Re: Boom Question

Post by tartansailor »

Andy Denmark wrote:Richard,

There's plenty of room for a 4:1 outhaul on your stock Cape Dory boom. If I were closer to my boat (3200 miles away) I'd get a quick picture and send it.

Your problem, as I see it, is two systems in conflict at the concept level. The "adjustable reef track" at the end of your boom is the problem as it takes up the space where the "side" portion of the multi-purchase outhaul system needs to go.

The concept level difficulty is this. You have adjustability hardware on the aft reef point where adjustability is unnecessary. A reef point's position never needs adjustment ... it's either full on or full off. That position is determined by the reef cringle placement on your mainsail and that position never changes. On the outhaul system, its position changes continually, especially on a loose footed sail. The hardware for this adjustment needs room to mount and that's right where the "reefpoint adjustment track" is located.

The solution is simple; take off the reef track (a consignment store is where it rightfully belongs) and get your sailmaker to show you where to put a cheek block and opposite-side eyestrap in the proper reef point position for your new sail. If the holes where the track was mounted bother you then stick a pop rivet in them. Booms are made of aluminum to make placement of hardware for vangs, topping lifts, reefing gear, luff tensioners, etc, easy to change.

John's boom on Far Reach has a non-standard (i.e., not Cape Dory) aft end. His system is great with the 4:1 (or more) tackle located somewhere else. Your "standard" Cape Dory boom end is totally different from that on Far Reach. Both systems work fine ... they're simply different.

FWIW, my CD-27 can be easily rigged for 6:1 on the outhaul, not for increased power but for more finite control of foot tension, a critical adjustment for sail shape with a loose-footed mainsail. There's plenty of room for even that using Harken mini blocks (I only used the 6:1 for racing which I no longer do).

Hope this helps. BTW, you'll love that loose footed main!

Andy
Hi Andy,
You raise a good point, and am taking it to heart.
My new 6 oz. main has 3 reef cringles because of a bad experience in a blow with my old fixed foot main, and that is why I chose to install a slider. Let me practice some panic dousing in calm conditions without the slider, and see if I can get rid of it. I really wish to have a very refined outhaul system (as well as all sail controls).
Thanks to all again.
Richard
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