Downhaul Cleat Solution

Moderator: GreenLake

Re: Downhaul Cleat Solution

Postby tomodda » Mon Jan 25, 2021 1:54 pm

Only use it for a year, then throw it out and rig up a dynamic boom downhaul? Well, maybe it was aluminum, it didn't rust. Bottom line is that I just had a bit of metal rod, with two holes tapped into it.
tomodda
 
Posts: 554
Joined: Sun Aug 12, 2018 9:04 am

Re: Downhaul Cleat Solution

Postby Alan » Mon Jan 25, 2021 5:42 pm

I did the same thing - 1/2-inch solid aluminum rod in the sail slot, held in by two machine screws. It's a Dwyer DM-284 mast, so maybe this won't work on a Proctor, but it makes for a solid attachment.

I used the method in two locations: Just above the cuddy roof, with a big padeye to attach the boom vang, and just above the mast hinge, with a Harken 40 swivel cleat for the downhaul.

All I had in mind for the downhaul was keeping the boom from riding up. The original cleat for that purpose was a small horn cleat, and I didn't feel like I could get it secure enough not to let go at an awkward moment.

I didn't know there was such a thing a a dynamic downhaul. Now that I do, I'm glad I spent the money for the fancy-schmancy swivel cleat.

Now all I need to do is invent a 2-to-1 cascade for my 6-to-1 vang, and then find a lot of free time to try it all out . . .
Alan
 
Posts: 736
Joined: Wed Jun 17, 2009 4:39 pm

Re: Downhaul Cleat Solution

Postby GreenLake » Mon Jan 25, 2021 6:41 pm

I would like to know what the difference is between a "dynamic downhaul" and a Cunningham and when to use each, before even thinking about rigging anything.
~ green ~ lake ~ ~
GreenLake
 
Posts: 6235
Joined: Mon Jun 18, 2007 3:54 am

Re: Downhaul Cleat Solution

Postby tomodda » Tue Jan 26, 2021 1:57 am

Boom downhaul. I believe you called it a dynamic downhaul, sounded good to me! Either way - downhaul or Cunningham, you're tensioning the mainsail luff. More than you can by just pulling on the halyard, and usually the peak of the sail is at the top of the track anyway, so no space to pull it. Simplest way to get more tension on the luff is just to pull down on the gooseneck. Which is what I do with my "dynamic downhaul," or whatever you want yo call it. It's a 2-1 purchase using a cascade, attached to a hole in the bottom of my gooseneck fitting (handy, that!). But using it means that I wind up pulling my boom below Band-2, which is illegal for racing. Most sailboat classes have the same issue, at least for Bermudan rigs anyhow. So Briggs Cunningham came up with the brilliant idea of pulling on the sail itself, without moving the boom. Usually a hook that goes into a cringe (reinforced hole) low on the luff of the main. Works great, except it screws up the airflow along foot of the sail and is ugly! But it stays within class rules, thank you, Briggs - you sly old dog....

But... As I've written before, I'm not racing. In general, I try to stay class legal, but here's where I diverge. Love my boom-dynamic-downhaul thingy! :) Better flow, better boat Feng-shui. Actually, it probably doesn't make any real difference, but it's easier to rig. First year, I used a Cunningham and I'd constantly forget to hook it on. To each his or her own...
tomodda
 
Posts: 554
Joined: Sun Aug 12, 2018 9:04 am

Re: Downhaul Cleat Solution

Postby GreenLake » Tue Jan 26, 2021 1:53 pm

OK, so, since I have a Cunningham, making that more easily adjustable under way would be the thing (and work better since my boom should would need to go lower than not only the class rules, but also what I need for efficient vang angle). Also doesn't interfere with vang setting, for the same reason. Cunningham isn't needed at the lower end of the wind range (light to almost moderate) so I don't get as much use of it here as I would in a different location.

Thanks for the historical note.
~ green ~ lake ~ ~
GreenLake
 
Posts: 6235
Joined: Mon Jun 18, 2007 3:54 am

Re: Downhaul Cleat Solution

Postby tomodda » Tue Jan 26, 2021 4:26 pm

GL:

Yes, all rigs have tradeoffs, and my "boom downhaul" has the problem that it takes up space at the bottom of the mast, where space is already in short supply/high demand. For what it's worth, I have two "bails" (C-shaped straps) on the lower mast, one right at the tabernacle, one some 3 inches above. The lower bail is actually on the rear pin of the tabernacle itself, so that's where I clawed some space, at the expense of one more thing to do when I'm putting up the mast. The vang is attached to lower bail, and the bitter ends of my boom downhaul go to the upper, as do the bitter ends of my vang cascade. Some creative work with high MWL snap shackles keeps it all compact and rotating efficiently as the boom swings around. The other end of the downhaul (the working end) goes thru a stand-up block on my cuddy roof (that I got on super-sale, $30) and then into a cam cleat at the cuddy lip (another sale, I'm cheap and patient). Historical note - "Bitter End" refers to the fixed end of a running line, which - in wooden ships days - is attached to the "bits", those square wooden brackets you see on old boats. Before you ask, the other end of the running rigging lines gets held by a belaying pin on either a pin rack, attached to a bulkhead, or a "fife rail," freestanding. Nowadays, we use cleats, thank Neptune!

Back to your Cunningham setup, you can easily add a purchase to the line. What I used to have before I went over to a boom downhaul is a line tied to the gooseneck as far back as I could get it, that then went thru the cringle and ended in a small block. Then I had another line coming from somewhere (mast bail or the gooseneck, I forget?) that went thru the block and down to a horn cleat on the boom, up forward. Pull on that line, sweating it against the boom cleat as needed, and I'd get a good bit of tension on the luff, as desired.

As for "dynamic," I seem to remember that when I was using a Cunningham, it was either full on or full off, the purchase was just to help me pull it "on." As you noted, you need to adjust the luff depending on wind speed, it's a tool for flattening the sail. I do adjust the boom downhaul somewhat more finely, basically it's off, 1/2 way, or full on... corresponding to wind strength. Don't know if it makes a real difference, but I don't have reef points, so it's nice having a few "gears" in my mainsail-flattening rig. Likewise, the cleaner foot that you get with a boom downhaul is not really a factor, because most of your drive comes from the upper 1/3 of the sail. In other words, I wouldn't switch from a Cunningham to a Boom Downhaul "just because." I did it to simplify my rigging (one snap shackle, done!) and to free up a cleat on the boom. My next set of sails will definitely have reef points, so I'll need that cleat (slab reefing). But I'm still keeping my boom downhaul, mostly because I've grown to like it and ease of rigging.

Tom

P.S. I think I sunk $150-$200 into 4 snap shackles, even with cruising the online sales. They are a huge time- and space-saver, but you definitely need to spend some money on top quality, no skimping! I like Ronstan, so I got that for all my snap shackles. Yes, there's some cheap chinese stuff out there, $12 snap shackles... no way I'm putting the load of my vang + the load of my halyard on those, even if that load is "only" in the 600-800lb range. Snap shackles need to open when you want them to, and not open when you don't want them to, period. That's worth spending on. Apologies for "preaching to the choir!"
tomodda
 
Posts: 554
Joined: Sun Aug 12, 2018 9:04 am

Re: Downhaul Cleat Solution

Postby GreenLake » Tue Jan 26, 2021 6:14 pm

I have a horn cleat for the boom downhaul. I never adjust that one, so I use the same cleat for the Cunningham. One end has a loop that I hook over the cleat, the other end goes up, through the cringle and down and I cleat it at the same place (cleat gets a bit crowded, but it kinda works). So, I have a 2:1, if you will.

About shackles: I'm using a pretty beefy "snap hook" for the vang. It's rated to about the same as the block that's attached to it, so that either one might be the "weakest link" in the setup. As it's a hook, it can't be opened under load, since you cannot remove if open because of the shape. I don't see a reason to open a vang under load - if it opens due to failure, it's only because the block held out above it's rating.

There's a maximal force on the vang, other than perhaps shock loads, that's given by the sail force that would exceed the righting moment (resulting in capsize). I did the calculation for that estimate at the time and convinced myself that having a hook rated at 800lbs was enough. If you have numbers why that estimate should be wrong, I'd love to know what they are.
~ green ~ lake ~ ~
GreenLake
 
Posts: 6235
Joined: Mon Jun 18, 2007 3:54 am

Re: Downhaul Cleat Solution

Postby tomodda » Tue Jan 26, 2021 7:03 pm

800lb is about right. And about what the MWL is for the lighter Ronstan gear, so works for me. No, I'm not releasing snap shackles under load, but I find them the easiest for any connectors you want to get off and on quickly.
tomodda
 
Posts: 554
Joined: Sun Aug 12, 2018 9:04 am

Re: Downhaul Cleat Solution

Postby jalmeida51 » Tue Jan 26, 2021 9:14 pm

I can get the luff tight with the boom down haul in about 7 knots or less. ( no scallops ) Anything above that I use the cunningham to remove the scallops. I have a Harken pivoting lead block with a cam cleat. The cunningham hook goes through the cringle. The more you bend the mast with the boom vang, you will get more scallops. That is when the cunningham is needed to remove the scallops . I remove the scallops on the foot by coming in hard on the 4 to 1 boom outhaul.

Happy Sailing, John
jalmeida51
 
Posts: 188
Joined: Fri Mar 02, 2018 9:51 pm

Re: Downhaul Cleat Solution

Postby Fly4rfun » Tue Jan 26, 2021 9:54 pm

I would like to see some photo's of your setups. Please !!

G.
"Sail Aweigh" 1966 DS1 #2675
Fly4rfun
 
Posts: 269
Joined: Tue Oct 13, 2020 5:10 pm
Location: Salem, WV

Re: Downhaul Cleat Solution

Postby tomodda » Tue Jan 26, 2021 11:27 pm

I'll look thru my photos and see if anything worth posting as well.
tomodda
 
Posts: 554
Joined: Sun Aug 12, 2018 9:04 am

Re: Downhaul Cleat Solution

Postby jalmeida51 » Wed Jan 27, 2021 12:15 am

Sorry I have no pictures of either system.

John
jalmeida51
 
Posts: 188
Joined: Fri Mar 02, 2018 9:51 pm

Re: Downhaul Cleat Solution

Postby GreenLake » Wed Jan 27, 2021 2:17 am

2679

I have a photo showing my "non-system", though not very well.

You may be able to see the white line with flecks right aft of the mast that goes up to the Cunningham cringle (which is not in the frame). It comes down the other side. Both ends are tied off on the same cleat hidden between the bunched up halyards.

(I use a bowline to make a loop on one end, and belay the other end). If I wanted easier adjustment, I could keep the loop over the horn cleat but run the other end down to some cam cleat on the mast or the cuddy top. Not sure whether making that adjustable will be the biggest bang for the bucks, so to speak, so at this point, I'm just aware of the possibility.
~ green ~ lake ~ ~
GreenLake
 
Posts: 6235
Joined: Mon Jun 18, 2007 3:54 am

Re: Downhaul Cleat Solution

Postby Anstigmat » Fri Jan 29, 2021 11:57 am

IMG_6814.JPG
IMG_6814.JPG (194.21 KiB) Viewed 1091 times


IMG_6814.JPG
IMG_6814.JPG (194.21 KiB) Viewed 1091 times


None of the hardware solutions I've tried seem to fit so far. Rig Rite asked me to try sliding the gooseneck from the base of the mast but the little neck before the tube did not quite fit, wasn't long enough to allow it to slide in. This method hadn't occurred to me but of course that makes sense if my opening is too small. I'm going to try it with my original gooseneck but I suspect it also won't fit.

Does anyone have or have info on this proctor mast? I'm just looking for anything. Selden has no info and I really just want basic hardware. The guys on the phone at Rig Rite are not particularly helpful. :(
Attachments
IMG_6809.JPG
IMG_6809.JPG (183.7 KiB) Viewed 1091 times
Anstigmat
 
Posts: 58
Joined: Thu Jul 23, 2020 12:50 pm

Re: Downhaul Cleat Solution

Postby Anstigmat » Mon Feb 01, 2021 10:30 am

I have a gooseneck that fits!

Lots of dremeling basically. Don't ask.

This particularly gooseneck has no loop for the downhaul. I was thinking of installing an aluminum loop on the boom pretty much where it meets the gooseneck and then tying that down to the downhaul cleat.

Any thoughts?
Anstigmat
 
Posts: 58
Joined: Thu Jul 23, 2020 12:50 pm

PreviousNext

Return to Racing/Performance

Who is online

Users browsing this forum: No registered users and 1 guest