Tuning question

[seawolf]

Hello all,
I am helping a friend tune his 26' Ranger.
Unlike the rig on my Columbia 29 which has upper shrouds in line with the mast and a baby stay forward of the mast, this rig has upper shrouds in line with mast and lowers forward of the mast. No aft lowers.
There is no turnbuckle on the jib stay.

My two questions are:
1-Since the forward lowers arrest the mast at the spreaders, is this set up to allow for a little more bend at the top of the mast, with the backstay, along with keeping the mast to pump in a heavy chop?

2-Are the forward lowers a little more effective than that of a single baby stay in front of the mast?

[Brion Toss]

Hi there,
That's an unusual configuration. As you say, this will tend to impose bend, but not, I think, as much as a babystay would, given the larger angle of the babystay to the mast. If lower shrouds are "swept" fore and/or aft, it is to allow some degree of fore-and-aft staying, in addition to their primary role of lateral staying. But imagine that this rig had only aft-led lowers; in the absence of swept spreaders, or some other geometry to oppose the pull of the lowers, the mast would tend to invert as the shrouds were tightened. In the same way, forward-only lowers will tend to pull the mast forward, but most likely leave it more vulnerable to pumping, especially when hitting chop.
But it could get even worse. Depending on the amount of sweep, any forward bend might only be accomplished by excessive tensioning of the lowers, because the forward component of pull is too small. This will make for a lousy lateral tune, undoing any gains made in fore-and-aft mast shape.
I might be sounding curmudgeonly here, but in the absence of compelling evidence to the contrary I'd say your friend's boat is misconfigured, and that the best thing would be to tune as for athwartship lowers, leaving any fore-and-aft bend to the backstay, ideally in combination with a hefty masthead crane.
Fair leads,
Brion Toss

[seawolf]

Brion,
Thanks for your reply
After reading your reply to my post, I re-read my post. I failed to mention that there were lowers in line with the mast along with the lowers that were forward.

Was the nature of your reply due to the fact there may have been only forward lowers along with the uppers for lateral stability? If so, sorry about that.

Or is forward lowers without the aft lowers still an odd set up?
Bob