Effective Low Cost Stay Tensioner?

[rardiH36]

The attached photo is a crop from a photo* I've seen on the "SF Bay Sailing Weather" website ( http://windandtides.com/).

Any opinions on whether this arrangement is an effective way of controlling stay tension for the budget challenged types among us? Looks real simple for a DIY'er. And from my boneyard box, I've got the blocks and other stuff to install already at hand.

thanks

(* The whole photo on the website really didn't seem to have anything to do with the tensioning apparatus that just happened to be part of the photo. The main theme was a picture of a happy man enjoying a day on SF Bay. I cropped him out since I don't have contact info to ask permission if OK post his mug in front of all that may be lurking around on this forum.)

 

[Tim C350 April IV]

Looks exactly like products that are sold with the express purpose of tensioning your backstay. Only comment I have is that it looks like a 2-1 tackle arrangement, and you might want additional leverage in there (e.g. 3 or 4-1).

Need to make sure that the mounting base connection is firmly attached to the boat, and will also want to make sure that you don't put too much gear in the way of the stern access.

Good Luck!
Tim Brogan
April IV C350 #68
Seattle

 

[sailingdog]

Just make sure whatever you're using can handle the loads on it.

 

[sailaway78]

Similar Setup

A friend of mine has a very similar setup on his Newport 27. Although I have not fooled around with it much, seems like a good workable idea.

 

[Roger Long]

Very similar to the one on my boat.

The one in your photo would easier to use if it had two part blocks.

With my masthead rig, I think of it more as a stay "Detensioner" because it lets me take the strain off the hull when the boat is sitting. It doesn't have a lot of effect on sail shape that you would notice cruising but it always makes me feel a little better to give it another tug when it seems like we've been beating for a long time.

Mine is attached with a snap shackle on the bottom. I have short line with a snap shackle and a loop spliced in it and another short length of line in the seat locker. This will quickly convert it into a MOB retrieval tackle by tying the slider to the stay junction and clipping the loop of the other line into the snap shackle. It comes down right beside the stern boarding ladder so would help assist an weak or incapacitated person back aboard.

 

[rardiH36]

Thanks all that have responded. And to those that probably are yet to do so. Good helpful insights.

For Roger: I didn't want to complicate my original posting with my motivation for the query. But you've hit the nail on the head. I also have a mast head rig. I've tightened the fore and aft stay turnbuckles up a notch and they seem quite taught, but in moderate/heavy blow (like the ~25kts on San Francisco bay we were out in today), there is noticeable slack/bend in the jib furler foil luff. I sense that pointing performance is compromized. Certainly sail shape is. So I am interested to tension more when it seems right to do so.

I'l give some thought to rigging for the MOB function. Thanks.

At the risk of exposing my "West Coast" lack of refinement, what esteemed institution of higher education is the "ODU" garment that you are wearing? Out here, I would wear a shirt or cap with "UCD". My daughter; "UCSC". (Hint: Don't pour salt on this school's mascot ... it will turn green and shrivel up.)

regards,
rardi

 

[Roger Long]

At the risk of exposing my "West Coast" lack of refinement, what esteemed institution of higher education is the "ODU" garment that you are wearing?

Old Dominion University in Norfolk VA. I got the sweatshirt by designing this boat for them:

http://www.rogerlongboats.com/odurv.htm

(That's why I design boats, to get tee shirts, hats, and sweatshirts

 

[Jim Kolstoe]

And here I thought that concept of a split backstay adjuster bowstringing the stays was common. On my h23 I have a purpose built piece of equipment I bought at our local chandlery a few years after buying my boat. It consists of two stainless steel plates sandwiching two small sheeves on each side to create the effect of a single much larger radius sheeve, plus a single sheeve on the bottom center that allows a 3:1 tackle by running the sheet through a double block at the other end. Coupled with a bendy mast, it allows easy adjustments of backstay tension to flatten, or ease, the main and headsail. I love it.
Jim Kolstoe, h23 Kara's Boo

 

[Joe]

That's a common setup for boats with split backstays. Here are a few others that may interest you. http://www.mauriprosailing.com/Harken/Harken-Trimming-Systems/Backstay-Adjuster.htm

 

[John]

If you have a swim platform and a step-through transom, is there any reason not to install such a tensioner in such a way as to be able to remove it to make the swim platform more accessible?

 

[Ray T]

That's the same setup I had when I raced my Cal 227. It was very effective for controlling head stay sag. I had a 4-1 setup on mine and I used to pull it as tight as I could. I think you might want more purchase for best results on your 36, at least 6-1. A friend of Mine Raced His Islander 37 with a hydraulic backstay tensioner and would tension it to 1500 lbs. I don't think you can get anywhere near that with a 4-1 or even 6-1.

 

[Anchor Down]

To the Original Poster,

The tensioner in your pic is exactly what I purchased from Garhauer Marine, but have not yet installed. I think this is top-of-the-line, despite it's less-than-massive appearance.

The encouragements for sturdy backing should be well-heeded.

Fair Winds,
Jeff

 

[Hermit Scott]

The same set up on my catalina 30 but instead of attaching the end in the middle of the split backstay on the transom, the attachment is actually to one of the sides of the split backstay allowing you to go through the backstay and down the swim ladder. To me it seems that it would pull the pulley arrangement to one side a little, but I guess it's negligible.
Also the benefit of this way would be you don't have to add another plate to the transom.

 

[rardiH36]

I'm the original poster. Thanks to all for good comments, considerations, and url links.

Yes, making sure that the attach point on my boat's stern gunwale or transom is adequately plated to distribute the load is important most definitely. And good idea to also keep in mind that a center run will be in the way of the stern ladder. In San Francisco Bay where I sail, however, my only use for the stern ladder is for MOB ... assuming the person is strong and coordinated enough to actually get him/herself back up in whatever wave conditions there are.

I might have been able to do it 30 years ago with knowledge from my physics 4a class in college still fresh in my younger mind, but now its beyond my inquisitive inclination to refresh the knowledge and apply to calculations. But .... my gut intuition is that although the more purchase of the block system (i.e. 3:1, 4:1, 6:1 etc) obviously results in more tension, also the squeezing together of the two split backstay wires will have a profound multiplier effect on the tension of the single backstay (further up) -- And by association, the forestay.

Although it will be a while before I get around to implementing the new apparatus on my boat: IT WILL BE DONE!

Again thanks for the considerations to the project.

 

[Stu Jackson]

KISS

sizing really isn't an issue because ya just ain't gonna bend a telephone pole mast.

Here's our Garhauer split backstay unit and we used a simple 4:1 vang also from Garhauer, offset to the side so we could use the ladder. We also raised the split to avoid head banging. The vang's mostly behind the outboard motor.

The distance you're gonna move it is maybe all of two to three feet. The difference in purchase is simply the amount of line you'll have sitting in your cockpit.

 

[Alan]

If I might suggest. Most of the designs that have been displayed and discussed are limited in pulling power the further the adjuster is applied. What may start out as a 4:1 or 6:1 quickly looses it MA as the blocks are pulled further down. This at the time when the MA is most needed. To overcome this reverse efficiency, I installed a single ball bearing block in place of the splitter at the top of the inverted "V". Then running a line from one corner of the transom to the other over this block. At each side of the coaming facing forward toward the genoa winches I placed a sheet stopper. By using the lazy winch, the backstay can be tensioned with far greater ease, power and efficiency with minimal need for the blocks and lines.

 

[larryw]

On a beat you honk that sucker down, but on a run, you let it off so the top of the mast can move forward

 

[Stu Jackson]

Another picture of a Garhauer adjustable backstay

Finally found one from the companionway looking out.