backstay working load

Seth

Sustaining Partner
I don't want to hijack your thread so let me know if I should just start a new one. You guys seem to have a handle on all this already so..
My question is 2 fold, should & how do I rig a backstay adjuster on a 30+ (split BS Fractional). I understand the principle with a split backstay but exact parts/procedure that will have enough purchase to be useful and will I need to install additional chainplates or? Any and all comments/opinions welcome.
Thanks,
Dave
 

K2MSmith

Member III
It is totally a mod. I worked at the factory and ran the prototype E33 race program. The optional backstay adjuster was hydraulic (not a great choice). Someone did this aftermark other
At least one other forum member said they replaced an internal purchase system on their E33RH with hydraulic so I assumed it was factory (?) .
Since you ran the race program, can you tell me a bit about the running backs ? Were some boats shipped without them ? I have heard conflicting opinions on their necessity to keep the rig safe . My spreaders have some sweep and when I’m single handing in moderate conditions I don’t use them ( they are bungee’d to the shrouds ) .
 
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Seth

Sustaining Partner
You can and should do an adjustable backstay. Many boats have a “squeeze” system which pull the split portion together. Look up Tartan 10 info and you can see the layout. It will really improve your performance. Where is your boat? I can probably recommend a local rigger who will know what to do something like this:
 

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Seth

Sustaining Partner
You can and should do an adjustable backstay. Many boats have a “squeeze” system which pull the split portion together. Look up Tartan 10 info and you can see the layout. It will really improve your performance. Where is your boat? I can probably recommend a local rigger who will know what to do something like this:
Or this (google split backstay adjusters and you will find tons of stuff:1608696699917.jpeg
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
Hi Dave,
I have the same arrangement as in Seth's pic above, and it works really well on our 1984 E30+. I would highly recommend it to flatten the mainsail, reduce heel, stop mast pumping in rough conditions, and make the boat more manageable. There is no need for a hydraulic system on our size boat.
Frank
 

K2MSmith

Member III
Pics ( not very good but it is cramped below deck ) of the internal backstay system. It is double ended ( can be adjusted from both sides of cockpit ) and it works very well ! Was raced by previous owner for at least 10 years .
 

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Dave G.

1984 EY30+ Ludington, MI
Hi Dave,
I have the same arrangement as in Seth's pic above, and it works really well on our 1984 E30+. I would highly recommend it to flatten the mainsail, reduce heel, stop mast pumping in rough conditions, and make the boat more manageable. There is no need for a hydraulic system on our size boat.
Frank
Hey Frank,
Where did you fasten the blocks to ? Do I need additional chain plates or will pad eyes work ? What purchase is yours ?
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
Hey Frank,
Where did you fasten the blocks to ? Do I need additional chain plates or will pad eyes work ? What purchase is yours ?
Hi Dave,
I'm guessing my boat came with the backstay adjuster from the factory, because I have a chain plate with turnbuckles on the transom, both port and starboard to which the stays attach. I then have a pad eye on both sides to which the blocks attach with a clevis pin with a cam cleat on one of the blocks to hold the line. I have a simple 4:1 purchase (I think??), and it's easy to apply and disengage with one hand. It looks exactly like the first pic that Seth posted above, not the google pic, and is much simpler than the arrangement on K2MSmith's larger boat.
Frank
 

Dave G.

1984 EY30+ Ludington, MI
Thanks, are the pad eyes in line with the chain plates or inside of them ? So 4:1 seems to work good for you ?
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
Thanks, are the pad eyes in line with the chain plates or inside of them ? So 4:1 seems to work good for you ?
The chain plates are mounted and thru bolted on the transom with a slight bend forward in each chain plate so the stay attaches straight to it. The pad eyes are mounted on the narrow flat top of the transom, so just forward of the chain plates. The 4:1 purchase works fine.
 

Kenneth K

Sustaining Member
Blogs Author
If the system IS a PO mod, and it's subject to hundreds of pounds of force, and it's holding up your rig, I might investigate the fasteners/method used on this piece of hardware:

rig.jpeg

Those are pretty small fasteners with no backing plates. Unless part of the hardware itself is glassed into the transom, it might be worth investigating.
 

p.gazibara

Member III
The loads on the rigging can essentially be the weight of the boat when going hard upwind and pounding into big seas.

The breaking strength of the nitronic 50 rod that was on Cinderella when I bought her was 10,000lbs (just about the weight of the boat)

The working load was probably about 20% of that.

The 9mm dux that I used for the new cascading backstay has a breaking load of 25,000lbs. Easiest way to deal with blocks is to go to low friction rings. Cheap, strong, solid.

-P
 

K2MSmith

Member III
If the system IS a PO mod, and it's subject to hundreds of pounds of force, and it's holding up your rig, I might investigate the fasteners/method used on this piece of hardware:

View attachment 36486

Those are pretty small fasteners with no backing plates. Unless part of the hardware itself is glassed into the transom, it might be worth investigating.
Good point. I have confirmed (via Seth) that this is definitely a mod - none of the boats were shipped this internal adjustable backstay. Since this system has a few areas where things can break, I have "backed it up" with a dyneema safety line that goes from the high load block on the backstay outside the boat directly to the chainplate. The line is sized so that it will tension when the backstay is adjusted to its full length limit.
 
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