Reefing with a sliding gooseneck
 

I have a 27 foot Cherubini designed Hunter that has a sliding gooseneck which is raised when reefed.

My question is: Is there any performance or safety issue if the boom is reefed by raising it 18 inches (more/less) rather than in it's normal sailing position?

The boom is a Kenyon boom, not sure what the sloop rig is or the mast.

The "T" track is about 2 feet long and the gooseneck slides on it. The sail track is a recessed "T" shape slug that terminates at the top of the boom slide track. (I read in another post that some of these were designed as a roller furling boom. There is no mechanism to indicate if this was possible and the end of the boom clearly would not be rotatable.)

The boat originally had a topping lift that got destroyed in a storm, I decided to replace the topping lift with a boom-kicker and a vang. The problem with this configuration, if the boom is lifted through more than about 12 inches, the boomkicker falls out of it's groove.

If I do not raise the boom, I need to remove the three (two?) lowest sail track sliders from their track to bring the sail down far enough to catch the horns with the cringle to hold the sail in it's place. Needless to say, this process is not very desirable and a real safety pain if I waited too long to reef.

It appears, if I can remove the slider and replace it with a fixed gooseneck (somehow), then the boom-kicker stays in place and none of the sail slides need to be removed to reef.

However, on the other hand, if there is no significant difference in performance or safety, I can continue to use my spare halyard as a makeshift topping lift and save all that other aggravation and costs.

Bob

I don't think the Hunter really needs it but the Cherubini's often think traditional. If it's wild enough to reef, it may be wild enough to get the boom up a bit where it won't dip into a wave.

It is fine to reef that way, as that track is the same strength the whole way along it.

Your spare halyard is not the makeshift topping lift, but it is the ideal topping lift...

There is a small thing...
 

This is probably pretty minor, but by raising the boom you are also effectively raising the center of effort of the sail. I'm sure the depth of your reef is greater than 18", so the rise in CE is probably pretty close to neutral, but it will still be higher than if you didn't raise the boom. A higher CE will mean what sail is left will have somewhat greater heeling force. Not something you'll likely need to worry about in one-reef weather.

Another point with the sliding gooseneck is it takes much less force to tauten the luff. Many boats which use it do not have the winch power necessary to flatten the mainsail for heavy weather without it. Similar to the Cuningham, the "first reef" as the wind blows up is a quick pull on the downhaul to flatten the sail and draw the draft forward. And any subsequent reef will likewise be hauled taut pulling down on the boom. I wouldn't be in a hurry to get rid of it, but go ahead and develop other techniques of maximizing its usefulness.

It makes more of a difference than you might expect
 

I have the same type of sliding gooseneck on my Bristol 34. Raising and lowering the boom--and the main--can make more of a difference than you might expect. In light air I sail with the main hoisted to the top of the mast and the boom about at the top of its track. I tension the luff with the downhaul. When the breeze picks up over about 14-15 kts I lower the boom to the bottom of its track and tension the luff with the halyard winch. Lowering the center of effort that 16-18 inches is my first "half reef".

When the time comes to really reef, I do it with the boom at the bottom of the track. It's true that a couple of the sail slides come out of the bottom of the track, but I don't find that to be a problem.

Jim Fulton

In case what the others have said needs any reinforcement, I sailed a similarly-rigged Irwin 27 between Maine and South America, and the sliding gooseneck was a handy thing to have. I would cast off the gooseneck downhaul when hoisting, hoist the sail as high as it would go, then heave on the downhaul to tension the luff. If I wanted it super tight, I would sit on the boom and then belay. The winch handles had been lost long before we owned the boat, and we never missed them at all, mostly because of the sliding gooseneck.
Ben

Photos included
 

By way of explanation, since words often fail, here is a "tiny URL" to photos of the assembly.

http://tinyurl.com/3axgrz

[ Long form URL ]
http://www.sailboatowners.com/upload...0926465&fno=17

The only detent stop is in the upper position. There is no stop in the lowest position.

With "Full Sail" up, the head is very close to the sheave (as would be expected) and the boom is pretty much in it's lowest position. There is no option to raise the boom up except when it's time to reef. First reef the boom goes up and the head of the sail comes down.

Second Reef (Buzzards Bay, MA) the head of the sail is reduced further. There is no 3rd reefing point.

Wave dipping: I had not thought about that as a feature, to prevent or reduce the boom tip from dipping into the waves.

The comment: Main Halyard is the ideal topping lift? Why would that be? I had the impression that the topping lift was for boat builders who didn't want to spend the money to add a rigid boom vang or some other such amenity (or a boom crutch) ? ? :D

We may get to see some of these ideas in action. Wind forecast is 10 - 15 on the bay.

Thanks for the ideas, :)

Bob

Is there a chance that the mainsail has been replaced, and is just a tiny bit longer than the original one was meant to be? It seems that at full hoist the gooseneck should not be at the lowest position. Unless there's some design nuance I'm not getting. Which is likely.

If there's no lower stop, how do you keep the gooseneck from sliding right out whenever you lower the sail? Must you ensure that the pin on the slider is engaged? A stop should be pretty simple to rig, as should a 'handy billy', as you call it.

I find a topping lift to be a must. How else, without a boom gallows, would you hold up the boom end while taking in a reef? Sometimes you need to tighten it so the sail's luff will bag slightly, instead of being pulled tight by the mainsheet (this was rare for me). Sometimes you want to heave the boom end up really high at anchor so your economy over-the-boom canopy still gives you headroom to sit in the cockpit when it's 100 degrees out. Sometimes you need it to turn the boom into a crane and heave heavy things aboard out of the dinghy.
Ben

Benz is dead on regarding the topping lift. It's not a poor mans substitute for a rigid vang. In fact, I prefer the traditional topping lift because it does provide for more options with the boom, a few of which benz covers well in his reply. It does sound like your mainsail is cut too tall. You should certainly be able to haul it down to tighten the luff. A downhaul is an extremely simple thing to rig but you have to put an end stop on that track. Your gooseneck already has a bail to attach a tackle to. As it is, you should install an endstop anyway as a backup should that pin not seat correctly. There is no reason I can see for raising the boom when reefing. In addition to shortening the quantity of sail in the air one of the big reasons for reefing is to lower that center of effort so that it has less leverage against the hull. As a whole I would say hoist with a loose-ish luff for light air, bear down on that luff as the air stiffens, then reef down with the boom in that same relative position for heavier air. I also notice that it looks like the boom is set up for internal reefing which you may or may not be using.

Multiple issues
 

Hi all,
There is a series of things going on here, that want untangling. In no particular order:
• The spare main halyard makes a great topping lift, until you need to use it as a main halyard, at which point you have no topping lift. So for those without a rigid vang, a pendant-and-purchase setup is most important. For those with a rigid vang, the spare main make a great redundant lift. Then, when you do sky the primary main halyard, you still have the vang as a lift. It's unlikely that both main halyard and vang would break at the same time, and if they do, you probably have bigger problems...
• It can be useful to keep the boom out of the water, but it makes no sense to raise the whole boom to do it. And in this case you must reef to raise the boom, so what would you do to keep the boom up in lighter airs? We sometimes see "tripping reefs" on mains'ls, on the leach, to top the boom end up when running, and this can be a valuable item. It is located not far above the boom, a foot or so, just enough to make a difference. But the tack stays where it is.
For the same reason, a properly-made sail will usually have the reef clews higher than the reef tacks, to get that boom end up. But the forward end, again, does not rise.
• Boomkicker has addressed the problem of the vang falling off the boom with an optional track setup. It's easy to install, and I recommend it. But in your case the problem is caused by the boom going upunnecessarily. This leads us to
• The reason why that track is there. As someone else suggested, it seems likely that your current sail is not properly made for this setup. What you have is a pre-Cunningham way to deal with luff tension, and it relies on having the boom somewhere near the top of the track when the sail is hoisted in light airs. Then, when you need to tension the luff, you take up on the downhaul. Works a charm, with the right sail. With yours, you cannot use the downhaul, except when reefed, right?
• Someone else mentioned tightening the main halyard as an adjunct to the downhaul. I can earnestly unrecommend this practice, as it has the unfortunate consequence of tightening the leach as well as the luff, and this is the last thing you want.
• The mains'l slide issue is a bear. Some boats will revert to a jackline in the bottom section, so the sail under the reef tack can get down to the boom. But this is an ugly way to do the job badly. If you can live with slides falling out when reefing, fine, but otherwise I suggest you
• Nail that boom to the mast. That is, pick a height you like for the boom, and drill and tap to secure the slide to the track. Throw away the downhaul and install a Cunningham. Simpler, easier, and considerably more effective at sail shape. Then cut off any of the heavy track that is above the slide (carefully), and extend the lighter track down to the slide. Simpler reefing, lower c of e, no jacklines, better sail shape. Ahh.
Fair leads,
Brion Toss

I must disagree
 

Pinning the gooseneck will result in *poorer* sail shape, and will more quickly distort a non-laminate sail material (probably also a laminate, but I don't have experience with those to say with certainty.

A sliding gooseneck with an end stop has one additional step when reefing - tensioning the downhaul. But this is simpler than attempting to tension the luff with the halyard, which with the fixed gooseneck results in working further forward and pulling down, an inherently less-stable position than being aft of the mast and pulling up. Having wrestled with both at night in lousy weather, my opinion is the slider is simpler in practice despite the additional step.

The sliding gooseneck can allow a lower c of e; that was in fact part of the point of *not* switching to the fixed gooseneck.

Jacklines or not is a personal preference, not related to the gooseneck type.

And I believe you have very easy access to a sailmaker to confirm my statement regarding sail shape.

Amgine

Why? What is the difference between a pinned gooseneck and one that is held fixed in place by a downhaul?

I think we agree here. I am just substituting a Cunningham for a downhaul. Note that I said that tensioning the halyard to tighten the luff is a bad idea.

It depends, of course, on the height at which you fix the gooseneck.

How so?
Amgine is referring to the amazing Carol Hasse, whose shop is just upstairs from mine. And who is a big proponent of Cunninghams. But I will check with her, in case I have this one wrong. Wouldn't be the first time.
Fair leads,
Brion Toss

Yes
 

Exactly. The only difference is the use of the Cunningham, which is an ingenious development to modify the shape of the sail on the fly but it creates a point load within the sail.

The sliding gooseneck has the same effect, but it spreads the load into the tabling rather than from a single point. All other points being equal, the gooseneck will result in slightly better shape and considerably less distorting loads within the sail.

As for jacklines, can you explain why they would be required for a sliding gooseneck with a stop? For that matter, I removed them from my gaffer as well after adding a pair of small teak buttons in lieu of a table. There is no need for the boom to fall to the deck without halyard tension.

It seems to work for me
 

I would like more of an explanation of the distribution of forces here. As I mentioned in the earlier post, I use the flexibility offered by the sliding gooseneck to raise and lower the center of effort by raising and lowering the whole sail. When the sail is raised to the top of the mast and the gooseneck is at the top of its track, I use the downhaul to tension the luff. When the gooseneck is at the bottom of its track, I use the halyard to tension the luff. (I didn't mention thatI have boom-end sheeting, which may or may not be important.)

In the one instance, the head is fixed and the gooseneck is moved; in the other, the gooseneck is fixed and the head moves. I don't see why the effect on the sail would be different. What am I missing?

Jim Fulton

Hi,
Good question, and I think one at the heart of this discussion. When you tension the luff with the halyard, you just about unavoidably also tension the leach. How much of the halyard's effect goes to either side depends on point of sail, sheet, and vang, but you'd have to impose some very strange evolutions, like topping up the boom, to keep the leach from being affected. But when you tension the luff with a downhaul or a Cunningham, the luff is the only thing that is affected.
In addition, tensioning the halyard has a diproportionate effect on the upper part of the sail, which is relatively small; tensioning from the tack flattens the belly of the sail.
The consequences for sail shape are significant, but I don't question that tensioning the halyard works for you; in many or most circumstances there will be a net gain in performance, with a flatter sail more than compensating for some leach curl. But it ain't optimal.
Fair leads,
Brion Toss