tension problem - when without a backstay

Posted By: Paul Germain
Date: 8/5/07 9:39p.m.

Report: outside forum guidelines

In Response To: A splint? (link) (George E. Norkus, Santana 2023A Tall, SE Michigan)

I put some time into adjusting the tension on my 27 foot mast that has a fractional rig. But I ran into a problem - which is rather difficult to put into words, so please bear with me. The tension cannot truly be balanced among the shrouds and forestay. Here is what I mean: On a masthead rig with with a backstay, the backstay will pull directly on the forestay at the attachment point because they share the same basic height on the mast. But the 2023 doesn't have a backstay and the upper shrouds that it uses instead don't match the same height as the forestay. Here is the problem: Since the upper shrouds are attached at a different height than the forestay, the more you tighten them, the more they pull on not only the forestay, but more significantly, the mast. Basically, tightening the upper shrouds causes the mast to bend more and more, while at the same time loosening the forestay. The same problem occurs the more you tighten the forestay. This problem is made worse by the fact that both the upper and lower shrouds pull backwards on the mast, whereas on other boats, they essentially pull sideways. So, when attempting to increase the tension of the lower shrould, the mast is bent backwards from the middle, which in turn changes the tension on the upper shroud and forestay. Theoretically, you cannot truly adjust or increase the tension properly, because the mast will just keep bending backwards in the middle the more you tighten the lower shrouds, which will in turn affect the forestay tension. Initially, you can create the proper tension, but it will be lost as the mast continues to be bent over time. On regular rigs, there are lower shrouds in front of the mast that will provide the opposite tension needed to keep the mast from bending. On boats with typical shroud arrangements that are fairly perpendicular to the mast, tightening the shrouds pulls evenly on the sides of the mast rather than to the rear. I found that putting the "correct tension" on the shrouds made the the forestay tension so tight that I couldn't attach or detach its pin on the bar where the roller furler drum attaches.