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Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Boom: Sliding or Fixed

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C25Guy
1st Mate

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USA
37 Posts

Initially Posted - 02/08/2009 : 12:42:40

Hi all. I'm trying to decide whether it's best to have the boom fixed at the gooseneck or free to slide up and down. On mine, it's free to slide up and down, and there's a downhaul from the boom led aft that has plenty of purchase for tensioning the luff without a winch. There's no Cunningham. I've got a light line running through the bottom few sail slugs to allow the sail to come down with a stop in place above the slot.

After a few years with this, I now have no idea why it is this way. For one, it makes reefing more difficult because the boom has to be brought up to meet the sail instead of just bringing the sail down. And often the boom jams in there and needs help when raising the sail to get to its proper level. Also, if I had a cunningham (just using the downhaul line that's already there), I think I'd have a lot more control over mainsail draft than with the current downhaul set up.

What does everyone do and why should I not fix my boom in place somehow?

Alan
"Maggie Mae"
C-25 #2815 SR/SK

Edited by - on

islander
Master Marine Consultant

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USA
4018 Posts

Response Posted - 02/08/2009 : 15:47:02

My boom is fixed so I don't have your problems but as far as reefing is concerned , I got rid of that sail track stop and installed the sail track gates from CD. This allows the sail slugs to come all the way down to the goose neck for reefing. Makes for a much nicer reef.

Edited by - on

Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 02/08/2009 : 15:57:45

I also added the gates. Then I put track stops above and below the gooseneck to effectively fix it--holding it up when I dropped the sail, and allowing the halyard to tension the luff. I still used the boom downhaul to keep some pressure off the upper stop. The gates aren't quite such a convenient option if you trailer-sail...

Edited by - Dave Bristle on 02/08/2009 15:59:31

Merrick
Navigator

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USA
192 Posts

Response Posted - 02/08/2009 : 17:09:13

I have wondered this same thing. I have a cleat below the sliding boom with an old line connecting them that keeps the boom from rising. Then when you lower the sail the boom drops to the cleat. Was there a purpose to this setup?

Edited by - on

Dave5041
Former Mainsheet Editor

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USA
3758 Posts

Response Posted - 02/08/2009 : 18:13:32

Pearl had that when I got her. Again, it limits the upward travel of the boom so you can have some tension. Unfortunately, while it does keep the boom off the deck, if it is high enough to allow use of the pop-top hook it severely limits downward movement and the ability to tension. I use a stop to support the boom so I can drop it when sailing and a four part downhaul led to the cockpit for tension.

Edited by - on

Deric
Captain

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USA
408 Posts

Response Posted - 02/08/2009 : 19:46:57

My system is very much like Dave's system -- see above previous post.

Track stops above and below, and a down haul line. Worked well.

Deric

Edited by - on

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 02/08/2009 : 20:02:40

Like Dave and the others, I put stops above and below the gooseneck which essentially makes it a fixed gooseneck. I've never used a downhaul but I do have a cunningham led back to the cockpit.

Edited by - on

Merrick
Navigator

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USA
192 Posts

Response Posted - 02/09/2009 : 11:15:59

ok what's the difference between a downhaul and a cunningham?

Edited by - on

pastmember
Master Marine Consultant

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2402 Posts

Response Posted - 02/09/2009 : 13:04:56

A Cunningham is a downhaul, it is simply in a specific place; where Brigs Cunningham told us to put it. The downhaul being discussed would connect to the bottom of the gooseneck slide and haul down on the boom. The Cunningham connects to a small cringle above the boom so it pulls down on the sail but not on the boom. Those of us with fixed goosenecks would only have the Cunningham.

Edited by - on

Dave5041
Former Mainsheet Editor

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USA
3758 Posts

Response Posted - 02/09/2009 : 19:09:41

The Cunningham takes the belly out of the sail to flatten it, the downhaul doesn't.

Edited by - on

Steve Milby
Past Commodore

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USA
5895 Posts

Response Posted - 02/09/2009 : 19:35:03

Wikipedia has a fairly good article on the cunningham. It says:

"The cunningham differs from a typical downhaul in the way that it attaches to the sail. The system usually consists of a line which is secured at one end to the mast or boom below the foot of the mainsail. It is then passed through a cringle in the luff of the sail near the foot, but above the tack, and then led down on the other side to a fitting on the mast or boom or on deck."

"The tension in the luff of the sail is adjusted using a combination of the halyard and the cunningham (where fitted). The primary advantage of adjusting the cunningham is the speed and ease with which the luff tension can be changed while sailing or racing. By hauling or easing the line, the tension in the luff can be changed, thereby shifting the point of maximum draft of the sail forward or aft, optimizing sail shape—and therefore—performance. It is a fine control which is used more frequently on racing sailboats than on cruising or day-sailing boats."

Many racing boats have both a downhaul and a cunningham. On my C25, I used the downhaul to adjust the tension of the mainsail luff for sailing downwind. When I wanted to sail to windward, I added tension with the cunningham. Then, when I wanted to sail off the wind again, all I had to do was release the cunningham. As the Wiki article says, the cunningham is a quick way to readjust the luff tension.

Edited by - Steve Milby on 02/09/2009 19:35:49

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 02/10/2009 : 08:28:53

As others have stated, mainsail luff tension can be adjusted using either the main halyard, downhaul, or the cunningham. Since I have a fixed gooseneck, I use a cunningham to tension the luff. Racers may be more avid users of the cunningham since it allows tensioning of the luff without exceeding the max luff length which may happen with the use of a downhaul. Generally, the halyard raises the main to its max hoist point and luff tension is applied from below.

Edited by - on

Dave5041
Former Mainsheet Editor

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USA
3758 Posts

Response Posted - 02/10/2009 : 11:42:19

Belay my last post. A traditionally positioned cunningham, which I don't have, doesn't really flatten the sail as much as a flattening reef, which I do have.

Edited by - on

Merrick
Navigator

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USA
192 Posts

Response Posted - 02/10/2009 : 14:56:18

<blockquote id="quote">quote:<hr height="1" noshade id="quote">When I wanted to sail to windward, I added tension with the cunningham. Then, when I wanted to sail off the wind again, all I had to do was release the cunningham.<hr height="1" noshade id="quote"></blockquote id="quote">

So is this a good general rule, tighten for upwind, loosen for downwind?

Edited by - on

Steve Milby
Past Commodore

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USA
5895 Posts

Response Posted - 02/10/2009 : 17:44:40

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Merrick
 <blockquote id="quote">quote:<hr height="1" noshade id="quote">When I wanted to sail to windward, I added tension with the cunningham. Then, when I wanted to sail off the wind again, all I had to do was release the cunningham.<hr height="1" noshade id="quote"></blockquote id="quote">

So is this a good general rule, tighten for upwind, loosen for downwind?
<hr height="1" noshade id="quote"></blockquote id="quote">It's a good general rule, applicable to moderate winds and stronger. In very light air you want to shape the sails so they generate the most power, which means you should ease the tension on the luff of both sails, and ease the tension on the outhaul of the mainsail, even when sailing to windward.

Edited by - on

C25Guy
1st Mate

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USA
37 Posts

Response Posted - 02/10/2009 : 18:22:29

Thanks for the discussion. I haven't really seen any argument that favors allowing the boom to slide up and down in the mast. The only trick will be pinning the boom high enough to clear the bimini and pop top but low enough to allow the halyard to be tensioned properly in high wind. I guess I'll just take the sail to the top, yank the downhaul hard and mark the final boom point just below the spot where it ends up. As long as I leave my drill at home and just use sail stops I'll be able to easily make a change if I mess up the measurement...

Edited by - on

HeelinPatrick
Navigator

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USA
102 Posts

Response Posted - 05/11/2009 : 10:15:27

Diggin' up an older topic...

My boom currently slides, unless it makes sense to 'fix it'. What kind of tension is applied to the downhaul, say beating upwind, or you guys with the fixed boom, how much halyard tension? Any idea of how much force to use? Seems like can slide the boom down a good bit, and I'm a little afraid to for some reason to put too much tension on, however don't mind giving it some good cunningham tension. I'm guessing you add downhaul just until you get the wrinkles and sag out of the sail along the luff?

Let me ask this too, would one start adding downhaul as needed, then when run out of that, start adding cunningham? Is there a reason to add cunningham, and not full downhaul on already?

Edited by - on

glen
Captain

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359 Posts

Response Posted - 05/11/2009 : 13:55:28

On Adventure a line runs through a reefing hook then through some blocks to increase its mechanical advantage. When I don’t need this for reefing it’s used as a Cunningham

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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.