backstay tensioner

[Del Wiese]

I have a split backstay and want to add a backstay tensioner. The upper is 9/32" 1x19 wire, rated at 10,300 lbs. The bridles are 1/4" 1x19, rated at 8200 lbs. I can't find info on the bend radius of 1x19 (or 7x19 either) but intuitively I think it is much greater than any block used for the tensioner. On previous boats I've used 7x19 for the bridles and had no problems. In order to match the current bridle rating, I will have to use 7x19, either 9/32", rated at 7800 lbs, or 5/16, rated at 9000 lbs. The problem is that I can't find any wire rope blocks that will accept more than 1/4". Has anyone solved this problem, or am I missing something?

 

[Frank Walker]

Divide by Two

Del, If the single backstay is loaded to say 10,000 lbs then each leg of the bridle would see only 5,000 lbs. I added a similar system to my Hunter 30 last year and the extra tension on the fractional rig really improves performance to windward. I used a Harken wire block on the end of the back stay, made the bridle out of 7 X 19 and a second Harken wire block on the stbd anchor point. I put a turnbuckle end on the port end of the wire and a copper stop and nicropress eye on the stbd end. That way if something in the tackle were to let go there is always some tension on the back stay. With the 2:1 in the backstay plus a second tandem 2:1 and a 6:1 purchase brings the total to 24:1. It is easily adjusted on my rig for a bend of about 1 mast diameter and as I said the windward performance of that fractional rig is greatly improved.

 

[Charlie]

B&R Rig

If your boat has a B & R rig do you really want to add a backstay adjuster. Will that unload the uppers and cause a structural problem with the mast?I also would like to add a backstay adjuster but have not since I am not certain what the overall effect would be on the rig.Is there any real knowledge on this subject out there?Charlie

 

[Del Wiese]

good question Charlie

Charlie, you raise a good question. When I bought the boat it had significant mast rake. Recently the back stay failed. It broke in the fork fitting, not a sweged fitting. I have fixed the back stay using Sta Lok fitting but plan to replace all standing rigging as a precaution, the boat was built in 1989. Right now I have no mast rake and will need to assess what that is doing to the uppers.