Backstay Tension for Beneteau393 with rolling
- Thread starter RodBry
- Start date
Because your boat has a masthead rig, backstay tension has little effect on mast bend; it mostly tightens the forestay and controls forestay sag. And pulls up the ends of the boat!
If you use your babystay, that will effect mast bend more.
In general, it is OK to add bend to a mast with a roller furling main while the sail is out, just remember to straighten it before furling.
If you use your babystay, that will effect mast bend more.
In general, it is OK to add bend to a mast with a roller furling main while the sail is out, just remember to straighten it before furling.
Thanks for the comments. I purchased my Beneteau 393 a year ago and the back stay tension seemed to be rather tight as the mast was bent a few inches backwards. I have released the tension some and the mast still seems bent. (Not sure if it is permanent or what.) I have just started some PHRF racing and would like to try and get the most out of her as possible. (I'm still learning. )
If the boat has a baby stay, the tension on it is going to induce some bend in the mast by itself and may need to be adjusted. I don't know if the forestay on the 393 has a turnbuckle in it. If so, you may need to add tension in the forestay. Otherwise, the only alternative is to install shorter tangs at the attachment points, or have a rigger shorten the forestay.
My 323 with no baby stay has similar issues, although I don't have to worry about the furler in the mast. When we step the mast in the spring, it's almost impossible to attach the split backstays to the boat (or if the backstays are attached first, to attach the forestay). After everything is hooked up, I have to adjust tension using a Loos gauge over several days using the lower shrouds to help take some of the bend out of the mast. By the time I'm done, I actually have a good inch of thread taken up in those almost impossible to attach backstays without any appreciable change in the tension gage numbers. It takes time, but I can get the forestay so that it doesn't sag excessively, and I have almost no weather helm. That said, I still believe that my mast is raked too far aft.
I might clarify that when I use the Loos gauge, I only tension to the numbers on the gauge that are recommended for the respective diameters of the shrouds and stays. I wouldn't want someone to envision the mast turning into an arrow driving itself through the bottom of the hull because of excessive tension.
My 323 with no baby stay has similar issues, although I don't have to worry about the furler in the mast. When we step the mast in the spring, it's almost impossible to attach the split backstays to the boat (or if the backstays are attached first, to attach the forestay). After everything is hooked up, I have to adjust tension using a Loos gauge over several days using the lower shrouds to help take some of the bend out of the mast. By the time I'm done, I actually have a good inch of thread taken up in those almost impossible to attach backstays without any appreciable change in the tension gage numbers. It takes time, but I can get the forestay so that it doesn't sag excessively, and I have almost no weather helm. That said, I still believe that my mast is raked too far aft.
I might clarify that when I use the Loos gauge, I only tension to the numbers on the gauge that are recommended for the respective diameters of the shrouds and stays. I wouldn't want someone to envision the mast turning into an arrow driving itself through the bottom of the hull because of excessive tension.
Do actually mean pre-bend, or do you see rake?? Some rake (mast not curved, but tilted back a few degrees) might be normal to get the desired degree of balance in the helm.