Winch Ignorance

[Bluenose]

In my Bluenose Sloop I happily sail without a winch handle. First because I never could find one of those old styles handles and second because the jib is small. In a pinch I run the leeward jib sheet around the leeward winch and trim to the windward winch. Then if I need extra power I just pull sheet that is running across the cockpit and trim in.

But back on the subject. I am trying to figure out if this could still be possible on the Shields. My question is what is the relationship between the tailing load, the winch drum diameter and the number of wraps. I feel stupid just asking but I must have put some other ?real valuable? information in that spot in my brain. My experience shows that the more wraps I have the easier it is to trim without having a handle but the slower it is to tail.

Could someone please help me restore this piece of information back into my brain?

Thanks, Bill

[Hirilondë]

Neither the number of wraps nor the size of the drum have anything at all to do with the force needed to pull the sheet in by hand. That force is the same as if you had no winch at all. The size of the drum does affect the force needed when cranking the winch in, but so does the gearing inside the winch and the length of the handle. The number of wraps affects how much friction the line (sheet) has to resist being pulled out or slip when cranking in. That is why 3-5 wraps on most winches is optimal going to weather and less in light air or well off the wind when loads are less. I hope that answers your question or at least helps to.

[Noah]

I'm not sure if you want to go this route, but on the Melges 24 we use a 2-1 jib sheet and no winches. It's very easy to use and works great.

Here's how it's set up:

The clew of the sail has two small blocks on it. The sheets run through the blocks and back to the jib cars where they tie off. The other end of the sheet runs through the jib lead, around a ratcheting turning block and into the cockpit. There is one cam cleat on each side of the cockpit per jib sheet. The first cleat is right behind the turning block and allows you to cleat the jib sheet off. The second cam cleat is on the other side of the cockpit and is "backwards". This allows you to put the sheet in both cleats at the same time (strung across the cockpit) and banjo the sheet buy pushing down when you really need to sheet hard.

This system works really well, and you can sheet the jib very quickly. Plus it's easy to teach others how to do (easier than teaching them how a winch works I've found).

I found some images at APSLTD.com that should help:

[Bluenose]

It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt. Mark Twain

Well, now that I have removed all doubt, thanks for the cob webbing clearing. I knew something in my thinking didn't quite fit I just needed a heads up. The funny thing is that after I wrote the post I went sailing and tried trimming with various wraps and in my imagination it did make a difference. So I decided to spread my ignorance around and ask an Engineer friend if my imagination was completely crazy. Here is his only possible explanation. The only way he could see that the number of wraps would make any difference is if the winch was tapered and the line entered the drum at a smaller diameter than it came off. If that was the case than the could be some mechanical advantage.



I went back to some photos and actually there is some of that in the old Merriman type winches on the Bluenose. I admit it seems small but the difference really seems perceivable.

I'm not sure if you want to go this route, but on the Melges 24 we use a 2-1 jib sheet and no winches. It's very easy to use and works great.

Here's how it's set up:

The clew of the sail has two small blocks on it. The sheets run through the blocks and back to the jib cars where they tie off. The other end of the sheet runs through the jib lead, around a ratcheting turning block and into the cockpit. There is one cam cleat on each side of the cockpit per jib sheet. The first cleat is right behind the turning block and allows you to cleat the jib sheet off. The second cam cleat is on the other side of the cockpit and is "backwards". This allows you to put the sheet in both cleats at the same time (strung across the cockpit) and banjo the sheet buy pushing down when you really need to sheet hard.

This system works really well, and you can sheet the jib very quickly. Plus it's easy to teach others how to do (easier than teaching them how a winch works I've found).

Noah, this is really a clever idea. The Shields has a similar sized non overlapping jib so I will have to give it some thought. I would really love to figure out a way to avoid having a winch handle since single handing into our narrow channel is a full time job without having to grind winches.

My inclination is still to go with sheet winches and use the "bango" method of trimming when needed. Then I would still have the ability to haul out the winch handles when I needed something heavy done. This really boils down to self tailing or not. If I don't need the handles everyday I won't be spending the bucks on self tailing winches. It is encouraging that the Melges get by without winches at all.

[Hirilondë]

If you don't need the mechanical advantage of a winch for sheeting in you might want to consider a snubbing winch. We had one on our Blue Jay when I raced it as a kid. It didn't make sheeting in any easier, but did make actively holding the sheet much more so. The 2 or 3 wraps add significant friction to resist the load of the sheet bearing on your hand, thus allowing you to keep it at the ready for quick adjustments or coming about.

The 2:1 sheeting system Noah describes is pretty clever. Skipping the wrapping of the winch on the new tack, and unwrapping the other one sure can make tacks quicker and easier. The only real down side I can see is longer sheets to store in the cockpit and more line to let out bearing off or tacking. It might very well be worth it though if it means you rarely if ever need to get out your handle and crank.

Looks like you have yet another one of the many compromises of sailboats to sort out.

[Tim]

I often sail without needing a winch handle for the jib, but when I need it I need it. I find I can do this up to about 12-15 knots of windspeed on the Triton with a 130%, at least if I can pull the sail in quickly after the tack, before the pressure builds. The handle is needed most for that final 5% of trimming, perhaps, or for heavier winds. I try to avoid using it whenever possible because it's just one more thing. As a general rule, I don't use the handle a lot.

As Dave mentioned, the intangible thing you feel with line on or off the winch drum is more about the increased friction that makes it easier for you to hold or pull the line. While it's easy to pull in and hold a jib on a winch drum (even without a handle, in applicable wind speed), trying the same thing without the friction of the winch drum would be difficult to impossible. This creates the illusion, I think, of increased mechanical advantage from the drum alone.

In a way, friction alone is a form of mechanical advantage, when increased friction allows you to better use your own force to pull the sheet (since with the friction of one or more wraps on a winch drum you use less of your own power simply preventing it from going back out).

I would think that the 2:1 sheeting system above could work on the small Shields headsail. Certainly the winches supplied on the boat are tiny and obviously don't have, nor require, a lot of sheer power. In any event, I expect that under most sailing conditions, you could tack the boat easily without needing a winch handle to properly tension the jib sheet. Non-overlapping headsails are pretty easy to do this with on any normal-sized boat; it's the overlapping sails that can be tougher to truly sheet in tight without the power of a winch.

But I think you need a winch drum or some other form of potential mechanical advantage (such as a multiple part purchase) to help hold the sheet, and to allow trimming in all potential wind conditions.

[Ric in Richmond]

I assume that sailing gloves come as standard equipment with line that light on the 2:1 system???

Ouch that stuff is thin!!!

Great idea though.

[Figment]

pshaw. You should see my light-air spinnaker sheets (which I use up to 15kts)!

So, are you not keeping the under-handled winches on Bolero? Those things are awesome!!!!

[Noah]

Our Sheets are way smaller than that! And tapered too...

But yes, I wear full fingered gloves when the wind is over six knots.

The ratchet block used probably provides as much resistance as a couple of turns on a small winch. Plus you can turn off the ratcheting when it's super light.

The Melges uses a continuous jib sheet, so you don't end up with too much extra line.

[Duncan]

...The size of the drum does affect the force needed when cranking the winch in...

And it also creates a mechanical advantage even when you're not cranking (i.e. independent of the gears), I believe.
(I think) this is because of the difference in the diameter of the spindle and the diameter of the drum (which can be thought of as an axle and a wheel). Per Wikipedia, on mechanical advantage:

Wheel and axle: A wheel is essentially a lever with one arm the distance between the axle and the outer point of the wheel, and the other the radius of the axle. Typically this is a fairly large difference, leading to a proportionately large mechanical advantage.

In the case of a winch, this would not be the "fairly large difference" they refer to, since the diameter of the winch drum is not that much greater than that of the spindle it turns on. It might be, say, 1.5 to 1, though, as you can sort of guesstimate from the photo above.

My question is what is the relationship between the tailing load, the winch drum diameter and the number of wraps.

It seems to me the answer to your question is that the tailing load decreases as the diameter of the winch drum increases (relative to that of the spindle it turns on). It may not be much, but it would be something, and you'd feel it?

[Bluenose]

So, are you not keeping the under-handled winches on Bolero? Those things are awesome!!!!

If at all possible yes! It will depend on what Tim finds when he starts tearing the Shields down and if any of the current parts are still good. I guess it also depends on how dear the winch makers think the under deck winch systems should be. I don't really know the setup for these under deck winches that the Shield uses. But I will soon.

Bill

[Shark]

Bill,

I believe Folkboats still use under-deck winches. Some Folkboat websites might yield some information about suppliers and parts etc. I imagine the Folkboat sails are a bit smaller than the Shields' but the winch specs might be similar enough.

[Noah]

You can still get Folkboat Winches that are through deck: $187 Euro.

http://www.cubitmedialine.dk/cruiser/?p ... Product=89

That said, I converted my Folkboat to the same setup as the Melges and it worked really well.

[Ryan]

...The size of the drum does affect the force needed when cranking the winch in...

And it also creates a mechanical advantage even when you're not cranking (i.e. independent of the gears), I believe.
(I think) this is because of the difference in the diameter of the spindle and the diameter of the drum (which can be thought of as an axle and a wheel). Per Wikipedia, on mechanical advantage:

Wheel and axle: A wheel is essentially a lever with one arm the distance between the axle and the outer point of the wheel, and the other the radius of the axle. Typically this is a fairly large difference, leading to a proportionately large mechanical advantage.

In the case of a winch, this would not be the "fairly large difference" they refer to, since the diameter of the winch drum is not that much greater than that of the spindle it turns on. It might be, say, 1.5 to 1, though, as you can sort of guesstimate from the photo above.

The problem that I see with the above explanation is that the wheel and axle effect is only applicable if you are turning the axle (winch spindle) and that in turn puts a force on the wheel (winch drum). This is the case when cranking with a winch handle. Just wrapping the line on the drum and pulling doesn't involve the spindle (its turning of course, but not working on anything). I believe that the "feeling" of mechanical advantage is explained by Tim, i.e. the fact that the wraps on the winch keeps you from having to exert much force to keep the line from pulling away from you makes the whole operation easier than if you just grabbed the line after it exits the fairlead and tried to trim and hold. I bet that would wear you down in a hurry!

[Duncan]

The problem that I see with the above explanation is that the wheel and axle effect is only applicable if you are turning the axle (winch spindle) and that in turn puts a force on the wheel (winch drum). This is the case when cranking with a winch handle. Just wrapping the line on the drum and pulling doesn't involve the spindle (its turning of course, but not working on anything)...

I think you may be right.

When you pull the sheet a foot, it moves a foot, whether it's wrapped around the winch or not, right?
I guess that means no mechanical advantage.

[Kristian]

Shields deck winches are generally Barient 10 winches with a under deck spindle. Let me know if you need some, I've got a few.

Lots of racing Shields use 2:1 jib sheets. The ones that don't usually cite slow trimming in tacks as the reason. Since you're not racing Shields I don't think that would be an issue. When we've experiemented with 2:1 sheeting, I find the best part is that you can trim the jib by hand, close hauled, up to about 20kts from the rail.

If it works with your plan I think keeping the Barients AND going to 2:1 sheeting would fit the bill. You can make the 2:1 shields jib sheet setup with a pair of Harken 40mm ti lite carbo blocks attached to the clew, and 2x 22' sheets.

There's no mechanical advantage to a winch tailed by hand.

[Rachel]

Kristian,

Please feel welcome to post a thread and photos on your Shields restoration! It certainly won't lack for an interested audience here.

Rachel

[Bluenose]

Kristian,

Please feel welcome to post a thread and photos on your Shields restoration! It certainly won't lack for an interested audience here.

Rachel

My second of Rachel's request is of course redundant, but here it is anyway.