Apache's Backstay Adjuster

[Mike Vaccaro]

Ron,

I was looking at the pictures of your backstay adjuster from the "Apache's Projects" posting from 2001.  Do you still use this set-up?  Have you found it to be effective?  Are you still using what appears to be a 4:1 purchase?    

Have you replaced the stock pins in the chain plate with D-shackles?  Did you have to modify the hole in the chain plate to accommodate the shackle?

Anything that you'd do different in hindsight?

Thanks for the help!

Mike

[Ron Hill]

Mike : I use the back stay adjuster all the time.  Especially if we happen to sail on the head sail alone (to keep the mast in column).

What I did was to take a 4 inch stainless tang and slightly enlarge one of the holes to the same diameter as the pin that hold the split in the back stay to it's chain plate.  My back stay pins were long enough to also accommodate the additional tang and a washer.  On the other end of the tang I slipped on a small stainless "quick link".  The link is also attached to 1/8" flexible 7/17 stainless cable which attachés to the 4:1 "Vang".  

The only change that I made years was to take the fiddle block and fiddle w/cam cleat back to Bill Felgenhauer and told him that his sheaves had fallen apart after 17 years!!  He gave me a trade in on some new ones with BB.  It's always works great and with the 4:1 going thru that center block you really have an 8:1 purchase.  

[Mike Vaccaro]

Ron,

Thanks for the reply.  Am going to rig one identical to yours but will use a 6:1 cascade for a total purchase of 12:1 (makes life better for the wife and kids!).

Cheers,

Mike

[Stu Jackson]

Mike

The 4:1 doubled purchase is more than enough.  By using a 6:1 you're going to use more line and have it fouling the cockpit.  You really don't need a lot of purchase, and you'll get a better "feel" for the tension with the 4:1.  Just a consideration.

[Ron Hill]

Mike : With my 4:1 vang for a total purchase of 8:1, I've NEVER had a problem.  I think as Stu said that may be an overkill.  Those are extra lines and they take up more space in that small area inbetween the back stay split.  
I used 3/8" line and needed 22' - as I recall.  

[dave davis]

I agree, the 4/1 slash 8/1 should be just fine. The only additional comment I would like to make is on older type boats like Ron's or Stu's or mine, is that when you tension the back stay, the V will come down and squeeze your head and ears together. Very uncomfortable. That is why on the low V older boats I would recommend that you shorten the back stay about 2 feet and lengthen the V by an equal amount. Yes this will cost you $ but it is well worth it.

[Stu Jackson]

To continue the spirit of agreeing with one another, I agree with Dave.

So much, in fact, that I used Dave's own sketch of how he raised his backstay split to avoid the very situation he just described.

It's VERY important that you do this.

I used a Garhauer split backstay piece.  It's a beautiful chunk of metal with two rollers (wire blocks) inside a nice shiny stainless steel pair of straps.  Instead of building a whole bunch of blocks and rings, try the Garhauer.  I remember it was all of $56 in 2001.

[SteveLyle]

Is the sketch available?

If the backstay is shortened by 2 feet - how do you adjust the turnbuckle at the split point to set the static tension - use a ladder?  Switch to 2 turnbuckles at the base of the split?

I got the thingy from Garhauer that Stu described a year or so ago, and haven't put it on because it's not wide enough to span the split of an unalterred backstay.  Plus when I got it I realized that if I put that thing on I'd be constantly hitting my head when helming from behind the wheel.  Though wearing a helmet when on the boat probably isn't a bad idea, given the head sink and the aft cabin and my habit of leaving the boom centered over the companionway.  Anyway, I've been wondering about raising the split, and didn't realize that it's been commonly done by Mk I owners.

[Stu Jackson]

Here's the scan of Dave's sketch.  I understand that Dave had made some modifications, which he can describe.  I raised ours to the height he suggested, it could go even a bit higher.  We NEVER have ANY head bangers, even when pulled in tight.  We used an old wooden ladder, four or five steps, to adjust the turnbuckle.  We had D shackles installed at the chainplates.  If you get a "wide-bodied" D shackle with the right sized pin, there's no need to drill the chainplate, just use the same hole.  We also purchased a Garhauer 4 part vang arrangement which works and looks great.  Many folks have commented on how neat the Garhauer sheave assembly looks (which is NOT what's on this drawing).

[Ron Hill]

Mike : Try my back stay adjuster with your factory OEM back stay.  I've always found that it's great without spending $$ to modify/shorten it.  If you don't like the adjuster as is, you can always spend the extra $$.

In Stu's sketch, mine goes all the way up and I think touches the triangular piece when not in use.  Mine parallels the existing split stay- not moving to the center as in the sketch.  In fact I use it  today-all day!!

The key to mine is that Bill Felgenhauer made two wire block sheaves (at my request) that will go all the way up in the 1/2" swedged fitting.  Think he charged me $20 for the two blocks.  Also, when the adjuster is not being used it's all of the way up so you don't bang into it when using the boarding ladder.  Can't remember if I put that in the Projects narrative or not - anyway now you know.  

[Mike Vaccaro]

Ron,

Thanks for the extra post--that's the plan, and we'll give the folks at Garhauer a call about the bocks as the idea of allowing the block to run up the fitting is right on the mark.

Cheers,

Mike

[Mike Smith]

Here is a discussion we had last year on this topic.

Mike

[Ron Hill]

Mike : Here's what I asked Bill to make me:
1.  A wire type block with a small 1 1/2" diameter sheave, so it could ride up on the swedged fitting.
2.  That the the sheave not be of a "plastic" material as there would be alot of pressure on the sheave.  Mine are brass/bronze.
3.  I sent him two of his small blocks (about 2 1/2" long) and asked that they be the same length.  Think he may have even used the cheeks off of those blocks.  

I also noted that in Stu's diagram that the 7/19 wire is longer than mine.  My wire is just on the other side of the center wire block so I have the longest run for the 4:1 vang.  

As I pointed out to Mike Smith (a year ago) you want to keep the pull on the chainplates at the same (as possible) angle!  This keeps an even  strain on all of the bolts holding the chain plates in place.  

[Stu Jackson]

1.  Clarification - That's NOT my sketch, Dave Davis worked it up.  He sent it to me, I scanned it years ago, and simply published it here.  He gets the credit.

2.  The Garhauer adjustable backstay is pictured below.  Mine doesn't ride up on the swages.  The reason I suggest raising the single backstay even higher is that even with the Garhauer unit all the way up with my single backstay as high as suggested in Dave's sketch, there is still a little bit of pull.  You could, as Ron suggests, work a wider one up with Bill or Guido.  I really like ours.

[Ron Hill]

Guys : I can see that the Back Stay Adjuster has made it to the same category as Politics, Religion, anchors, type batteries, regular vrs synthetic engine oil etc.!!!!!!!!!!!

The important things to remember about a back stay adjuster are:
1. 4:1 with an 8:1 purchase is sufficient to do the job.  More purchase will  make it easier, but maybe more cluttered.
2. Try to keep the angle strain as close to the existing chain plate strap angles that are mounted into the transom.  This puts less side strain on the fixed components.

I designed mine back in 1989/90.  You know, back in the Dark Ages BTI (Before The Internet).  
The only change I've made to mine has been the change out to fiddle blocks with ball bearings (after the old sheaves wore out!).  Even though I'm a TINKERER, it works great and I have seen no reason to change any of it's design.