Can I use the halyard as an effective downhaul?

COOL · Dec 17, 2009

You will lose nothing, as long there is enough hoist to fully tension
the luff of the mainsail. Sliding goosenecks are for the most part
a thing of the past. Generally the gooseneck is fixed solidly to the
mast, and a cunningham is used to tension the luff.

Scott T-Bird · Dec 17, 2009

I also am surprised that you have a sliding gooseneck. Your plan to raise the gooseneck to a point that clears the bimini is a good one. Of course, on a 30' boat, you will always have those trade-offs between comfort and performance. By raising the boom, you are effectively losing sail area. A lower bimini restricts your head room. Our boom is low enough to hit my wife in the head if we don't watch out and she is only 5'6" - it catches her just slightly above the temple. So we both stoop while under the bimini (and it helps to keep us safe!).

How high you can raise the gooseneck also depends on how your main sail is cut and you may run into the problem of not being able to hoist your sail fully if you raise the gooseneck too high for the current cut. You can always have you main re-cut to solve any problems and if you buy a new main sail, you may want to buy from a loft who will actually measure your boat rather than buy a sail from a discount place where you find the sail doesn't fit.

Long story short ... raise the gooseneck and fix it in place, make sure you have the right luff lenth when you re-cut or buy a new sail, and add a cunningham for luff tension at the bottom third of your sail. The halyard is good for tensioning the upper half to 2/3rds of your sail.

Steve Dion · Dec 17, 2009

Not sure how this would work, but a couple of options may be to:

1. Add a topping lift. This would fix the end of the boom at a fixed point.
2. Add a rigid vang. This would support the boom and prevent it from being too low. It also would add some additional sail control.

Garhauer Marine makes rigid vangs which are reasonably priced and realitively to install.

Joe · Dec 17, 2009

The sliding gooseneck is not a thing of the past if you have one... All the old catalinas were rigged that way. My C27 is rigged that way, with a 3:1 purchase on the downhaul. However, when I purchased a new mainsail some years back it had a cunningham cringle. (The cunningham is, in my opinion, a more effective way of tensioning the luff than a downhaul.) So.... what I did was tap screws into the slot above and below the gooseneck to fix it in the postion I wanted. Then I purchased a cunningham hook to convert the downhaul to a cunningham by leading the line up a foot or so to the new cringle.

The answer to your halyard question is "yes". You can use the halyard to set tension on the mainsail luff... the original masthead rigs of our boats had that in mind, realising the ineffeciency of the boom downhaul set up. However, Hermit, you will find it much more convenient to use a cunningham to tweak luff tension than the halyard. I use the halyard to set proper hoist, which is to the black band at the top of the mast, then use the cunningham to increase the main's luff tension.

Immediately, I suggest you hoist the sail an inch or two below the black band, then tie off the gooseneck. Now you can adjust tension on the luff with the halyard... with the gooseneck fixed in place. Later, as a fun project, you can fix the position of the gooseneck by tapping screws into the slot (not through the fitting) to keep it from sliding. Then rig a cunningham with a simple 3 or 4 to one purchase and run it back to a cleat near your halyards.

Paul F · Dec 17, 2009

Have the same problem with a new sail. The luff is shorter than the old sail but the boom still hits the bimini in stiff winds when sheeted in tight. Sailing friends have suggested lowering the bimini's front edge only. This is not what I want to do but seems to be the only available answer.

Plumper II · Dec 17, 2009

You could have a sailmaker take a thin triangular piece out of the foot of the sail so that the part of the boom over the bimini clears the bimini, but the forward end is still low on the mast. Many of the hot race boats have booms that are near the base of the mast and they angle up over the cockpit. You could do something similar but not as radical.

Joe · Dec 18, 2009

You could lower the bimini an inch or so.

If you've raised your sail as high as possible and the boom still touches the bimini then you'll either have to lower the bimini or shorten the sail to raise the boom. There is no other choice, unless of course you simply tie in a reef to reduce mainsail size.

On masthead rigs, the cunningham tensions the luff and controls draft POSITION (not depth) . Take a quick look at Don's sail trim guide to understand how draft position affects sail performance.

caguy · Dec 18, 2009

This is a repeat of an earlier post.
You might want to consider just changing your mast rake. With small degree of change to the rake you can significantly raise the boom clearance. Here is a small chart that demonstrates the clearance you can gain.

Ie. Just by changing your rake 2* you can gain almost 3'' of head room at the 7' mark of your boom.

Degree change _Rise at 7' __Rise at 10'
1 ______________1.47” ______2.09”
2 ______________2.93”______ 4.19”
3 ______________4.40” ______6.29”
4 ______________5.87”______ 8.39”
5 ______________7.35” _____10.50”

COOL · Dec 18, 2009

Hermit Scott said:
I thought a cunningham would take draft out of the sail with out tensioning the luff?

With the boom all the way up the slide, when I am sheeted in tight, the end of the boom is just a few inches off the bimini.
If I just use the topping lift to keep the boom off the bimini I do not have enough tension in the sail to go fast upwind.

A cunningham or topping lift will not help
your situation. What you need is more halyard tension
to get the headboard higher,which will also allow you to
get adequate leech tension upwind without
the boom hitting the bimini.
It is possible, if you have an older sail,
that the boltrope in the luff has shrunken
over time and is preventing you from
fully stretching the luff.

jibes138 · Dec 18, 2009

Catalina mast

I recall my 25 had a gooseneck the fit into the track on the mast as Hermitt is describing. I recall having a line attached to the bottom of the gooseneck to pull it down and tension the luff, not a cunningham but it actually pulled down on the boom, otherwise the boom is just floating and only the weight of the boom will set the shape of the sail, not a good arrangement. I'd suggest finding the right spot for the boom at the dock by raising the sail as far up as the halyard will pull it, slack off an inch so you don't jam the halyard shackle in the sheave, cleat the halyard, then pull down on the boom gooseneck to get the desired tension and maybe use a sharpie to mark the position on the mast. Then tie a line to the gooseneck and pull it down to that point and cleat the line off. Next time you raise the sail you should only need the halyard to tension the luff to start with. If the boom hits the bimini in this position you may need to recut your sail because raising the aft end of the boom will screw up your sail shape if the fore end is fixed. A topping lift should be slacked when sailing or it effects the sail shape also. The mainsheet and vang will be pulling down on the topping lift and not on the sail.