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Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

raising boom for bimini

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Johnnybob
1st Mate

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32 Posts

Initially Posted - 07/18/2013 : 13:39:23

My apologies for being being in the wrong place as this question concerns a 27' Catalina. My history with this site has taught me that the membership here has a lot of experience with a variety of boats and I greatly value the input I've found here.
I'm considering raising the boom about 12" to accommodate a taller bimini top. The goose neck seems to be easily raised however this will put the boom slightly higher than the slot where the sail slugs go in and out of the mast. I realize I would have to temporarily lower the boom or detach the goose neck to change sails. But other than that what problems am I creating for myself. The Catalina 27 has a huge Genoa and I don't think my performance will suffer greatly by eliminating 9-10 sq. ft. of sail from the main. I'm 6'3" tall and would enjoy a little extra headroom in the cock pit but I don't want to do something really dumb(my usual MO)for the sake of a little comfort. Any thoughts would be appreciated.

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britinusa
Web Editor

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USA
5404 Posts

Response Posted - 07/18/2013 : 13:44:44

John, you know that you'll have to trim the sails if you keep the boom up high.

Is there anything else you would have alter, such as Boomkicker?

If you can get a gooseneck that would fit into the slot, then you could leave the boom low down and attach the mainsail, then raise it up and reef the main. Just an idea to see how things go with the higher boom before you cut the sail.

Paul

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Steve Milby
Past Commodore

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5851 Posts

Response Posted - 07/18/2013 : 14:27:18

The simplest, least expensive way to do it is to have your sailmaker install one cringle in the luff of the sail one foot above the sail's foot, and another cringle in the leech of the sail one foot above the sail's foot. Then use it like a short reef, or flattening reef, but, instead of lowering the sail down to the boom, as you would in a normal reef, raise the boom one foot, to the reef cringles. By doing it that way, instead of cutting down your sail, or buying a shorter sail, your present mainsail will still have it's stock dimensions. You won't have a bastardized or odd-sized sail. If you want to race, or to sail in light air, you can always shake out the reef, to maximize your sail area, and then, when you want your overhead space again, you can simply tuck in the short reef.

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Stinkpotter
Master Marine Consultant

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Djibouti
9016 Posts

Response Posted - 07/18/2013 : 15:11:01

Do you have a sliding or fixed (attached to the mast) gooseneck? If a slider, Catalina Direct sells a fairly robust pair of "mast gates" for the C-25 that, if they work on the C-27 extrusion, should keep the gooseneck from popping out when you lower it to remove the sail or raise it after loading the slugs. You can ask them about whether the the plates work on your mast.

If the gooseneck is fixed, what about raising it only to just below the opening (maybe half a foot)?

Or, if you're not concerned about resale, you could cut a new opening higher on the slot. Then, for a sliding gooseneck, you could drill and thread a hole inside the slot so you could run a bolt into it with a washer against the edges of the slot as a permanent stopper for the gooseneck, to keep it from dropping down to the old opening. (Not sure that's clear...)

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John Russell
Master Marine Consultant

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3444 Posts

Response Posted - 07/18/2013 : 19:38:53

3 of the most knowledgeable have already responded and they didn't mention that you'll be raising the center of Effort for the sail foot as well so, it probably isn't really important. But, it was the first thing that came to mind when I read your question. Raising the center of effort will change the heeling characteristics of the boat at least. I don't know if it would be a little or a lot.

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Stinkpotter
Master Marine Consultant

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Djibouti
9016 Posts

Response Posted - 07/18/2013 : 20:07:44

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by John Russell
 ...you'll be raising the center of Effort for the sail foot as well so, it probably isn't really important. But, it was the first thing that came to mind when I read your question. Raising the center of effort will change the heeling characteristics of the boat at least. I don't know if it would be a little or a lot.
<hr height="1" noshade id="quote"></blockquote id="quote">But he's reducing the effort (sail area), so putting its center higher won't necessarily increase the heeling force.

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John Russell
Master Marine Consultant

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3444 Posts

Response Posted - 07/18/2013 : 20:14:22

See, Johnny, I told you they were smart.

I'm about to display how little I really know about the engineering side of all this but, doesn't raising the COE lengthen the lever and wouldn't that compensate for the reduction in sail area. At least in terms of heeling force?

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Steve Milby
Past Commodore

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5851 Posts

Response Posted - 07/19/2013 : 04:29:58

When I bought my boat new, I ordered a suit of sails from North, instead of buying Catalina sails, and North mistakenly sent me a mainsail that was about one foot too short. While they were making the correct sail, I used the short sail, and raised it to the top of the mast, which raised the boom about a foot. I didn't detect any significant change in the general behavior of the boat. Other members have bought and used shorter sails in an effort to raise the boom, and none have reported any bad results. I expect it might change the time when you have to reef by a little bit, but I don't think it would be significant, because you have to tuck a reef in a tall rig a bit earlier anyway, due to the mast being taller, the lever arm being longer, and because of the greater sail area.

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Stinkpotter
Master Marine Consultant

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Djibouti
9016 Posts

Response Posted - 07/19/2013 : 06:42:15

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by John Russell
 ...doesn't raising the COE lengthen the lever and wouldn't that compensate for the reduction in sail area. At least in terms of heeling force?<hr height="1" noshade id="quote"></blockquote id="quote">Think of it this way... You're removing the lower 1' along the length of the foot of the sail. The rest of the sail is the same (shape and height). The heeling force (and lever arm) from that remaining portion at full hoist is the same as it was before, while the heeling force from the bottom section is gone. Net: slightly less heeling force, even though the CE is higher.

Now, it's possible that a new sail, cut for this configuration, with the same foot length, would change the shape of that remaining area. But since both are cut with a roach, such that the leech is fairly vertical from the clew, the new sail would be very little different from the old one with 1' removed from the bottom. (And the new one will probably be flatter--less heeling.)

Alternatively, it could be he'll broach the moment he hoists the sail with the raised boom.

Edited by - Stinkpotter on 07/19/2013 06:46:15

sfsmith
Navigator

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USA
120 Posts

Response Posted - 07/19/2013 : 08:32:34

John, I did exactly what you're contemplating, and it worked out great. In the process, I switched the gooseneck from a fixed attachment to a slider, so I just lower it when I take the mainsail on or off. I use sail track stops above and below the sliding gooseneck to keep it in place. I've never had any problems. As noted above, it does put the COE higher, but that has not been a big deal.

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Johnnybob
1st Mate

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32 Posts

Response Posted - 07/21/2013 : 08:14:36

Thank you all for the excellent feedback. Yesterday I eased the boom vang and mainsheet and the boom easily slid up the sail track. The goose neck is mounted on a 6" long tab that slides in the sail track and is secured by 4 friction tabs much like a sail stop. It turns out that the spare main that came with the boat is about 10" shorter than the newer main so I changed sails and all I need now is a little breeze for a test drive. The boom is now 6'8" above the deck at the companion way and the same at the end of the boom just in front of the wheel. It looks like it's going to work and I'm pleased with the prospect of a roomy canvas enclosure. Thanks again to one and all for your experience and insight.

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