Why things are the way they are... sheets

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Why things are the way they are... sheets

Postby Breakin Wind » Mon Dec 24, 2012 10:28 am

During the cold months, when I'm not out in the cold pole barn working on my long list of winter boat projects, I spend my time I would otherwise be sailing (if it were 60 degrees warmer) either perusing the DaySailer.org forum archives reading old notes, or watching youtube videos on sailing techniques and other related materials.

This weekend, I was watching a video on adjusting Jib sheets while singlehanded sailing, and noted (this was not on a DaySailer) that on this boat the mainsheet was on the boom aft end but not rigged in the triangle setup but more like the center-boom configuration with a fiddle block upper, and becket/block/cam-cleat combo on the transom. In this setup, the sheet can be/is held in your tiller hand so you always have it in hand with a free hand remaining. Also, the jib sheets don't cut across the cockpit to the CB housing cam-cleats, but rather go through a block more or less where the jib sheet side blocks are on a DS, but then back to another block/cleat further aft. The result, no lines cutting across the cockpit.

From my minimal sailing experience last year, almost all of it singlehanded (except the time I nearly put my wife in the water). The one thing I've constantly wondered about, was why the jib sheet cam-cleats were so far forward. When Kokko took me out on his (Catalina?? sorry Kokko - hope I got that right) the jib sheets were also back on the sides of the cockpit, although that was quite a bit larger of a boat. While sailing last year, as I'd tack and come about, I had to reach forward, grab the loose jib sheet, stick my foot out on top of it as a lever, and then pull on the sheet to lock it down into the cam-cleat. jdoorly has moved his jibsheet cam-cleats further back on his custom sheet table, but they still cut across the cockpit.

So two questions...
1- Is there a practical, mechanical or operational reason on a DS why one could not use a center-boom mainsheet setup on the transom/boom end? For the moment exclude the fact that the rudder is aft mounted and the tiller cuts across what would have to be the attachment point on the transom. Maybe that's the reason for the triangle, but even in that configuration (what I had originally), the sheet ran forward to a center-boom block and down to a CB housing mounted block/cam-cleat.

2- Of more interest is the jib sheet question. Again, is there a practical, mechanical, or operational reason that the jib sheets shouldn't be side mounted and further back?

Thanks for the guidance... Scott
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Re: Why things are the way they are... sheets

Postby ChrisB » Mon Dec 24, 2012 12:21 pm

Scott,

Both questions have to do with the size and/or configuration of the DS as opposed to a larger boat.

1. Because the rudder on the DS is hung on the transom, the mainsheet has to be either triangular to each corner of the transom or it would have to be attached to a traveler mounted such the the tiller could move under it. On larger boats, either the rudder post is further forward (allowing the mainsheet to be attached behind the rudder post) or there is a cutout in the transom through which the tiller swings.

2. On a larger boat, there is some ballast in the keel that counteracts the force of the wind on the sails. As a result, you can sit on to the leeward side to trim and cleat the jib without the risk of capsize. Because the DS ballast consists of the helmsman and crew, you need to be able to make sail trim adjustments (main, jib, and spinnaker) from the windward side of the boat. This is typical of all un-ballasted centerboard sailboats. When I sail solo, I tie the two ends of the jib sheets together with a double sheet bend so I can reach either jib sheet without leaving the rail.

Chris
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Re: Why things are the way they are... sheets

Postby dannyb9 » Mon Dec 24, 2012 5:02 pm

i sit forward so that the mainsheet cleat is nearly in front of me if i'm facing the centerline of the boat, for good fore and aft trim and maximum hiking leverage. the main and jib sheets are within easy grasp if one is sitting up near the centerboard case. i use a tiller extension almost all the time.
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Re: Why things are the way they are... sheets

Postby kokko » Mon Dec 24, 2012 6:55 pm

Glad to see you were paying attention aboard Surprise. The jib sheets are further aft because the keelboat is more forgiving. I occasionally cross my jib sheets so I can sit to windward.
On Truelove I have scrapped the Crosby rig for 5:1 mid boom sheeting.
DS1 Truelove
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Re: Why things are the way they are... sheets

Postby dbk0630 » Tue Dec 25, 2012 5:49 pm

I added a set of fairleads to my centerboard cam cleats... to keep both ends of the jib sheet at the centerboard cleats. That simple change made the jib much easier to handle... especially when single-handling. Best $15 I spent this year!
Dave K.
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Re: Why things are the way they are... sheets

Postby GreenLake » Tue Dec 25, 2012 6:43 pm

I have seen at least one picture of a boat that had a U-shaped section in the tiller, so that you could swing the tiller side to side, even though there was a main-sheet that was attached to the center line in the back. Another advantage of the rear triangle is that it gives stronger sideways (inboard) component of pull for the same main sheet tension. On a DS the mainsheet controls both leech tension as well as sheeting angle. Ideally you could vary the angle of pull freely (which a traditional traveler allows you to do) - next best thing is to use some (fixed) arrangement that gives a good compromise.

If you pull too steeply downward, you flatten the sail more than you sheet it in, or vice versa for a pull that's too flat.

When you sail the DS you will get the best results if you balance the boat. Heeling is understood, but you also want to not sit too far back. If you do, the transom sits in the water and acts like a brake (it tries to pull the water in the lake behind your boat). The forward position of the jib sheets is also determined by the location of the fair leads, which in their turn determine the downward angle of pull on the jib. One could use blocks etc. to lead the jib sheets further back, but then this would encourage people to sit too far back for balance. As @dannyb9 wrote, that position really benefits from a tiller extension even when you are not actually hiking.

The operation with having a foot on the jib sheet to lock it in the cleat should not be necessary. First, with some practice you can sheet home the jib before it's fully loaded, and usually it will stay in the cleat even if you have to make a small final adjustment. It's a matter of timing. Having a set of fairlead on the thwarts, with cleats on the CB trunk, makes it so that the angle at which you pull will more naturally lock the sheet into the cleats. Just don't overdo this, because you want the sheet to be easily cast off in response to some gust or other emergency. That must be possible from all seating positions w/o the need for an exaggerated upward pull on the sheet.
~ green ~ lake ~ ~
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Re: Why things are the way they are... sheets

Postby jdoorly » Wed Dec 26, 2012 5:30 pm

Hi Scott, When I got my DS2 the running rigging/ground tackle for the jib and main were stock. The jib sheets would fall out of the 40 year old Schaeffer cam cleats and were hard to get cleated due to the too small wood wedges under the cleats. The main worked fine but in my efforts to minimize the length of sheets and control lines, and increase leverage I switched the stock 3 to 1 to midboom 4 to 1. I think the reason for O'Day running the sheet end forward to the CB was the way it naturally falls to hand there and doesn't require the occasional and distracting peek aft. Also, one hand naturally falls on the tiller while the other can keep tabs on the mainsheet. If you try to control both the sheet and tiller with one hand you will find when you want to trim/ease the sheet the first thing you do is grab the tiller with your other hand, this is not efficient.

Everything is a compromise, but I'm pretty happy with my jib sheeting system. In the following pic you can see the old wood wedges as well as the new table with cleats and wedges.

897

The UPS cleats (aft) have bigger wedges than the jib cleats because the angle to the blocks is different, it probably wouldn't hurt to have bigger wedges on the jibs but that's $17 I can spend elsewhere where it's needed more.

After soloing for years I find this system comfortable for the various sailing conditions, had I not I would have changed it.
DS2 #6408 "Desperado"
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Re: Why things are the way they are... sheets

Postby GreenLake » Thu Dec 27, 2012 12:23 am

One benefit of a raised "table" for arranging jib cleats is that there is less downward angle between the fairlead and the cleat. If you have a DS1 you have thwarts that allow the mounting of eyes to change the direction (down from fairlead to eye, up from eye to cleat). The original setup is marginal for cleating, as it's nearly impossible to pull the jib sheet downward while hiking. So out comes the foot trying to push the jib sheet down so it can be cleated. The same geometry makes it really easy to release the sheets (even accidentally), because by necessity they lead up from cleat to hand. (Inevitably that leads to the desire to cleat the jib early during the tack, before you have to hike out).

The table setup continues that arrangement, but by being higher, the angles involved are shallower, and just by looking at it, I would expect it should be much easier to pull the jib sheet at the new angle, even when sitting out, so cleating in can be done without the help of other limbs.

The padeye on the thwart design should redirect the jib sheet so that your wedges on the CB would have to point the other direction, leading to a natural direction from cleat to hand. That should make cleating much easier, possibly even too easy, where the cleat would "grab" the sheet when you simply want to hold it in your hand. I haven't tried that layout yet, but I know that effect from my mainsheet layout. The extra eye does add friction, so increases the effort to sheet the jib hard when the wind is strong.

So Scott, you now have the comparison of three designs for you to study. There's a fourth, which is to have the cleats on the same car as the jib fairleads. There, the difficulty is that the cleats require a pull towards the aft to set them, while, ideally, you'd want to operate them from the windward side while hiking or even simply sitting on the windward side. (This dependence on seating is the main reason, after all, for having the jib sheets cross the cockpit). Most people who wrote about this see more problem than solution in that setup.
~ green ~ lake ~ ~
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Re: Why things are the way they are... sheets

Postby DavidF » Wed Jan 02, 2013 5:03 pm

I am hoping to install new cam cleats on the CB trunk this spring before I drop my DSII into the water. Right now, the cleats are combined with a fairlead on the jib car tracks.

Can anyone suggest a cam cleat size or model? Also, my CB trunk has angled faces on the top that I assume were intended for the jib cleats. Is that what they are really for?

Thanks,

David.
1977 DS2 #8687
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Re: Why things are the way they are... sheets

Postby GreenLake » Wed Jan 02, 2013 5:28 pm

Cleat size depends on your line diameter for the jib sheet. I believe mine are the second smallest size made by Harken. I've used Ronstan cleats in some locations, they seem to work just as well. Haven't tried any other brands. Just looking at the online catalogs should allow you to pick the right model - again, line diameter is the deciding factor here.

Since the wedges are already molded into your CB trunk you don't need to buy extra wedges with your cleats.
~ green ~ lake ~ ~
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Re: Why things are the way they are... sheets

Postby jeadstx » Wed Jan 02, 2013 6:55 pm

DavidF,

I mounted cam cleats on my DS2 CB trunk where the angled areas are. I used cam cleats from Duckworks with a fair lead. I removed the original cam cleat assembly from the jib car and replaced it with a block.
Image

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
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Re: Why things are the way they are... sheets

Postby jeadstx » Wed Jan 02, 2013 7:00 pm

1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
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Re: Why things are the way they are... sheets

Postby GreenLake » Thu Jan 03, 2013 3:19 am

The racelite stuff is noticeably cheaper than what I used. Always a consideration (although, all things being equal, I tend to prefer looking at things in a store, helps me visualize my projects).
~ green ~ lake ~ ~
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Re: Why things are the way they are... sheets

Postby Breakin Wind » Fri Jan 04, 2013 12:01 pm

jdoorly wrote:Everything is a compromise, but I'm pretty happy with my jib sheeting system. In the following pic you can see the old wood wedges as well as the new table with cleats and wedges.

897

The UPS cleats (aft) have bigger wedges than the jib cleats because the angle to the blocks is different, it probably wouldn't hurt to have bigger wedges on the jibs but that's $17 I can spend elsewhere where it's needed more.
After soloing for years I find this system comfortable for the various sailing conditions, had I not I would have changed it.


Hi Jay,

If you have the inseam measurements for your table legs (looks like a nice snug fit to the CB housing) and would be willing to share them, it would be greatly appreciated. After sitting in my boat (in the cold) for an hour pretending to do various things, I can see how you arrived at this design, and once again, it seems like a perfect solution for me. Some day I'll get creative on my own and quit borrowing (stealing) from your designs but until you stop doing it right, it's really hard to step around them without pausing to oogle.

Thanks - Scott
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Re: Why things are the way they are... sheets

Postby jdoorly » Fri Jan 04, 2013 9:56 pm

Thanks Scott, twarn't nuth-in! I want to thank my Mother and Father, my kindergarden teacher and her "Magic Blocks", and my Fifth grade Detention monitor, and Mrs...

I have some rough measurements I can give you but I fit the cleat table by trial and error to get about a 1/16" clearance against the CB trunk along the inner legs, so that the 3M 5200 would not all squish out. If I remember correctly there is some 'oil canning' in the trunk surface you should look for and the legs may need a slight curve on the inside. (You can probably replace the 5200 with 4200, but it's easy to access if you want to take it out).

But first the caution. This design is not based on any known engineering forces and is therefor subject to suspicion and failure.

I have a UPS of 72 sqft attached to it that has withstood 30 degrees of heel (the standard measure of full load, more heel and the sail surface is reduced) upwind and reaching with no perceived movement, and no sign of movement or breakage when inspected over the course of several years. However, the leverage of the sheet pulling on the CB trunk should probably be equalized by a thwart similar to such used by DS1's or a better one with a height equal to the table. The trade-off is a divided cockpit. This would appear also true for the trunk mounted mainsheet cleat. Hopefully, Uffa Fox ran the numbers on that and O'day didn't move the thwart too far forward cause they didn't want a divided cockpit! And when O'day decided they could save x.xxx manhours by not having a thwart on the DS2 cause the double hull should make the CB trunk stiffer. I'm inclined to think it does but I am still debating the issue with myself.

I made the table out of a 1" (actual 3/4) by 8" (act. 7.5) by 48" oak plank. I ripped the plank to 6".
The sides are 3/4x6x15 (act. front and back)
the top is 3/4x6x12
and the rest taken from leftover pieces.

The CB trunk profile is approximately
4" across the bottom with an outward fillet curve to the floor
2.5" across the top
9.5" tall

I glued it all up, stained it "golden oak", waited a few days then epoxied (u.s.composites), then varnished with "Flagship". That's the way I go; cheap epoxy and expensive varnish.

It was nearly finished when I decided I wanted to add the bottom (horizontal) piece. It looked a little spindly for something that had to take some force. I don't know if it's really needed or not, the glued surface area is much stronger than a few screws in thin fiberglass, but it makes me feel a little fuzzier. I have since made pockets out of open weave cloth to hold sheets on the sides, and attached blocks on the front to provide purchase for the the CB uphaul and downhaul.

My suggestions for you are to reduce the height from 15.75" to 12.75 to reduce the lever on the CB trunk, and think about some thwarts or some other way of holding the table in equalibrium, possibly removeable, but if you lower the table that might be enough. Also, an aesthetic note: Done again, I would replace the side wedges (gussets) with an arch. The table is a great place for a compass, and a compass is a great thing to have in current, in darkness, and in fog. But get one with 'lubber lines' so you can read it at an angle. It's also a great place for a drink holder, or a handle of some sort for guests to hold as they change sides. But, be carefull not to foul the mainsheet if you have a sheet at midboom.

We all stand on somebodies shoulders, and so it goes.
DS2 #6408 "Desperado"
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