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Catalina/Capri 25/250 Sailor's Forums

Catalina 250 Specific Forum

Using the downhaul

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frejoh
Navigator

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USA
116 Posts

Initially Posted - 05/30/2009 : 08:14:59

Y'know, it occurred to me that I can't remember ever adjusting the downhaul...lazy of me! And there it is, with block, tackle and all. Is it like the outhaul, taut in higher winds and slack in light air to allow the mainsail to be deeper? Who has any guidelines, tips or advice on the correct use of the downhaul? (I'll take my lazy self to the owner's manual now, too.)

Fred Johnson
250 WK #669

Edited by - on

frejoh
Navigator

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USA
116 Posts

Response Posted - 05/30/2009 : 09:13:31

Well, I hope downhaul is a decent synonym for boom vang, otherwise I sound like a bozo.

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

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USA
4479 Posts

Response Posted - 05/30/2009 : 09:38:02

Fred,
A downhaul is a line rigged to the top of your sail through a block at the tack to enable you lower it from the cockpit with force (as opposed to gravity). Your [url="http://en.wikipedia.org/wiki/Boom_vang"]boom vang[/url] is attached at the foot of the mast and about 1/4 to 1/3 of the way aft on the boom. It's job is to help with sail twist.

Edited by - on

Nautiduck
Master Marine Consultant

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USA
3704 Posts

Response Posted - 05/30/2009 : 10:30:22

Here is a nice article on using the boom vang. Like David wrote it is used to control the amount of twist at the top of the sail. When you let the mainsheet out and the boom moves away from the center of the boat it will also rise. The vang pulls down on the boom to counteract this.

[url="http://www.andrews.com/kysc/bt/boomvang.htm"]Boom Vang[/url]

Edited by - on

zebra50
Captain

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USA
408 Posts

Response Posted - 05/31/2009 : 08:20:35

The definition of the downhaul from the Nautical dictionary is
"1) A line from the boom at the throat led to a block or becket at the deck, which is used to stretch the luff of the sail flat when beating, or which can be slackened to allow the sail to belly when running. 2) An accessory line used to haul a sail down so as to take slack out of the luff." My 250 has one at the mast through a grommet at the just above the tack and back to the other side of the mast.

Edited by - on

essen48183
Navigator

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USA
143 Posts

Response Posted - 05/31/2009 : 08:40:45

Not that it matters, but none of us have a downhaul, they are for sliding goosenecks only. Ours are fixed goosenecks. From your description, the grommet you are referring to is probably a cunningham.

My last boat had a downhaul, you raised the mainsail by hand easily all the way to the top and cleated it on the mast, and then pulled a 4:1 downhaul that pulled the front of the boom down and the luff tight. A sail stop held the front of the boom up when the sail was doused.

a cunningham tightens the luff down by just pulling the sail itself down and the sail ends up bunched up a bit beneath the purchase point.

I have heard the small line some people attach to the shackle of their halyards in the event that they accidently find it at the top of the mast unattached to a sail called a downhaul, too.

Edited by - essen48183 on 05/31/2009 08:47:28

Dave Brown
Navigator

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USA
174 Posts

Response Posted - 05/31/2009 : 10:42:07

Fred Johnson
250 WK #669,

You are correct!!!

Having raced Hobie cats for 17 years, a Laser, a Windsurfer, Iceboat, Hunter 23.5, Catalina 250, ext ext ---. A down haul does just what you said, it does, It moves the pocket in the sail Fwd. and aft. In the way you described it. As you can see from the above responces, dif. boats do it in a dif. ways.

Good Sailing.

Dave B.

_______________/)_________________/)___________/)))____________

.

Edited by - on

AADIVER
Admiral

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USA
966 Posts

Response Posted - 06/01/2009 : 23:07:12

My "downhaul" is a line attached to the first grommet below the head of the main, drops down and thru a shackle at the base of the mast, then back to the cockpit thru a cam cleat mounted aft on the sliding hatch cover. It helps me haul down the main when I douse it.

Edited by - on

Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 06/02/2009 : 06:55:35

For purposes of this association, which has a variety of fixed and floating goosenecks, can we agree on a set of distinct terms? I submit:

Downhaul: Line (or tackle) that pulls the boom downward at the gooseneck to tension the luff.

Dousing line: Line attached at or near the head of a sail to douse it (pull it down).

Many of us have or had both.

Edited by - on

Steve Milby
Past Commodore

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USA
5902 Posts

Response Posted - 06/02/2009 : 07:59:02

Either a downhaul, or the halyard, or a cunningham can be used to tension the luff, but there are some interesting differences in the way they work.

When the luff is tensioned with a halyard, the mainsail is usually not under load, and the tension is evenly distributed along the entire length of the luff. If you try to add halyard tension when the mainsail is under load, the tension will usually only be applied to the upper half of the luff.

When the luff is tensioned with either a downhaul or cunningham, the mainsail is often, but not always, under load, and the tension is only applied to about the lower half of the luff of the mainsail.

As a result, the next time you tack, and the load on the sail is released, the tension spreads to the entire length of the luff, and the luff might begin to appear scalloped, and require re-trimming. It's not so much of a concern in light or moderate winds, but in strong winds, it can make a real difference in sail trim.

Many people, including some very experienced racing sailors I have seen, adjust their luff tension the same way every time they sail the boat, but that isn't the way it should be done. Generally, you should apply the amount of luff tension necessary to make the luff smooth, but not so much as to pull vertical curls along the length of the luff. That means the amount of luff tension should increase proportionately to the wind speed. In really strong winds, it doesn't bother me if the sail has vertical curls in the luff when the sail is unloaded, as long as the curls smooth out when the sail is under load. But, if that is the case, then you should remember to ease the luff tension when the boat turns downwind.

Edited by - Steve Milby on 06/02/2009 08:43:48

Arlyn Stewart
Master Marine Consultant

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USA
2980 Posts

Response Posted - 06/02/2009 : 11:23:01

Good Replies by all.

Randy has it very well said about the vang but I'll offer a couple of points. The vang is primarily an off wind adjustment as Randy points out to reduce the twist of a loosely sheeted sail.

However, (and I note you have a wing keel and a traveler but water ballast models don't and this comment is for the benefit of water ballast owners), a vang can substitute when a traveler isn't equipped. In that case sheeting is done by 'vang sheeting' and the mainsheet is used as the traveler adjustment.

Keep in mind that certain conditions have to apply for this to work but it does work well on a 250.
<ol type="1"><li>The purchase power of the vang has to be modified and increased</li><li>The vang must be rugged with rugged secure points</li><li>Vang sheeting has wind limitations that need to be kept in mind</li></ol id="1">

The advantage of this is that doubling the purchase on the vang is very cheap and easy to do compared to installing a traveler. The disadvantage is that sometimes a traveler is wanted in demanding wind conditions that will be beyond the safe scope of vang sheeting. My best guess is that vang sheeting is safe up to about 12 kts of wind. I've used it often but I'm cautious about its limitations. Also, by 15 kts, my boat will have at least one reef taken so I don't wish to scare any one not to consider vang sheeting in lieu of not having a traveler.

The limitations exist for two reasons
<ol type="1"><li>The load handling ability of the vang </li><li>The need to quickly be able to twist off and depower the main</li></ol id="1">

One can note that to dump power, both the vang and mainsheet have to be eased so at least twice the time is needed to depower.

Edited by - Arlyn Stewart on 06/02/2009 11:25:48

Dave Brown
Navigator

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USA
174 Posts

Response Posted - 06/02/2009 : 15:44:30

Hay Fred,

Know ya know everything we all know,
BUT--- did we answer your question???

???

_____________/)___________/)___________/))))________________

.

Edited by - on

frejoh
Navigator

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USA
116 Posts

Response Posted - 06/02/2009 : 19:12:57

Yes, indeed, thanks, guys! Your responses and a little reading led me to conclude I should consider tightening the vang when sheeted out on the main, to prevent the boom from rising and distorting the shape of the main. I have also probably not been getting the most out of the main by neglecting to ease the topping lift once the main is hoisted and holding up the boom. Whast effect do you think that has? Keeping the main too "baggy?" (Classic nautical term there?)

Edited by - on

essen48183
Navigator

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USA
143 Posts

Response Posted - 06/02/2009 : 19:53:15

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by frejoh
 Whast effect do you think that has? Keeping the main too "baggy?" (Classic nautical term there?)
<hr height="1" noshade id="quote"></blockquote id="quote">
The effect is basically inefficient sailing, aft draft and no power from the top half of your sail causing you to sheet in too far to compensate. You were healing more (and dragging more with hull shape and rudder drag from the correction, and getting less power from your sails.

She's gonna fly for you on your next ride! I wish I could see the look on your face when Zepherus grabs that forestay and pulls you like a freight train riding on a rail. Happy sailing!

Edited by - on

Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 06/02/2009 : 21:15:04

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by frejoh
 ...I have also probably not been getting the most out of the main by neglecting to ease the topping lift once the main is hoisted and holding up the boom. Whast effect do you think that has? Keeping the main too "baggy?"<hr height="1" noshade id="quote"></blockquote id="quote">The topping lift basically changes the air flow from aft to upward and twists off the top--not even the right kind of "baggy" for light air. Slacken the TL, set the vang, and you'll fly! For "baggy", ease the out-haul.

Edited by - Dave Bristle on 06/02/2009 21:25:10

Arlyn Stewart
Master Marine Consultant

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USA
2980 Posts

Response Posted - 06/03/2009 : 05:38:49

This reminds me of a story.... We were sailing the North Channel and near the end of the day and entering the Benjamin Islands to anchor for the night, noted that the Trailer Sailors Group was anchored the other side. They departed early the next morning and we took chase of the dozen or more boats in the group though they had a large head start.

A couple of hours later, we caught up to the trailing boat, a couple of miles behind the fleet. Coming abreast and saying howdy, the skipper lamented that yesterday, he'd had no problems in keeping up with the fleet but today his boat seemed very sluggish.

I pointed out that his topping lift had not been eased. He couldn't believe that he'd not noted it.

Edited by - Arlyn Stewart on 06/03/2009 07:19:24

Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 06/03/2009 : 08:06:25

Hey--a new control... If you're cruising and want somebody in a slower boat to be able to keep up (and you're not too proud to mess up your sail shape), lift your boom! Or, if the situation is reversed, ask them to.

Edited by - Dave Bristle on 06/03/2009 08:14:32

frejoh
Navigator

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USA
116 Posts

Response Posted - 06/03/2009 : 18:29:22

So that's why everybody's been passing me! Can't wait for the weekend-no more lazy sailing, at least not too much...

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