Beneteau 285 Backstay Tension Block Setup

[AldernyRace]

Hello,

I just bought a Beneteau 285 '89 and she has the split backstay with two blocks and a ring in the middle. There should be a 4 to 1 block setup with a cam cleat to increase mast tension I think but it didnt come with anything. I'd like to know what others have setup and or any advice. Line size. Block size. For example can a smaller dingy 4 to 1 block set be use since it's not under much tension. Or is there a totally different way that works? Pictures would also help.

Thanks in advance.

 

[SoSound]

Congratulations on your First 285, and welcome to the Forum! The first boat that we purchased was a '90 First 285, and we loved it! I can provide the picture, but no specifics regarding line size or other details as that was handled by our previous owner. I do know that the blocks in this photo appear to be original era. I cropped the photo to focus on the adjuster itself. Good luck, and enjoy!

 

[AldernyRace]

That's perfect. Thanks Dave!

 

[jssailem]

Welcome to the SBO Forums. Congrats on your new sailing boat.

I suspect you are looking at a fiddle block for the upper and a fiddle block with a cam and becket for the lower.


Harken makes them in a 40mm, which would be more than strong enough for this task.

Line diameter would depend on the size of the sheaves in your blocks. I think 5/16 or 3/8 would be more than enough and would provide a good hand feel.

 

[AldernyRace]

Thanks John

 

[shemandr]

... Line size. Block size. For example can a smaller dingy 4 to 1 block set be use since it's not under much tension...

The sizes are a matter of numbers. You should look at the anticipated loads on the backstay and choose rigging that is able to withstand those loads with a 7 to 1 safety factor.
While the loads on a backstay will at times be low - as in sailing downwind in less than 12 kts. without a spinnaker. At other times the load on the backstay could be significant - like sailing up wind in a breeze. You will want it to be tension on, to reduce sag in the headstay, depower the jib and bend the mast to flatten the main to depower it.
Harken's blocks are often described by the size of the boat - dingy, small boat, big boat, etc. - which makes it fairly easy. From the specs you can get the safe working load and choose your line accordingly. Running rigging can be aggressively downsized with modern fibers but the material has to be able go around blocks and hold in stoppers and cleats. UV resistance is important in the backstay application too. You may want an abrasion/UV resistant cover.
They're a lot of choices. I think it best to start with the numbers.

 

[AldernyRace]

Very helpful. Thanks for the detailed post!