Rig tuning a 40' cutter

[rcassano]

The boat is a Baba 40:

The last time I had a professional rigger static tune the mast I asked if he was going to remove the Schaefer roller furling drum on both the jib and staysail in order to get the headstay and staysail stay adjusted. His answer was that they were fine and it was not necessary. My question is this:

1. How does he know they are fine when tuning the rig should start with loosening "all" the wires and starting from scratch?

2. Isn't the entire tuning process faulty if the head stay and staysail stay tension are ignored and not included in the "start from scratch" - "loosen everything" basic, Brion Toss rule for starting the rig tuning process? (as stated in the "Tuning Your Rig" video).

3. If the tension on the headstay is not sufficient would this put way too much tension of the forward lowers when the hydraulic back stay is pumped up to flatten the main?

As a boat owner and not a professional rigger I was wondering if maybe I was missing something here? In any case, I'm going to try to adjust and tune the rig myself to see if I can, at least, get things in the ball park. Any advice on the headstay/staysail stay tension would be much appreciated.

[Bob Pingel]

Headstay tension is typically not measured directly because as you mention the furler kinda gets in the way.

Headstay tension is gauged by spar shape and backstay tension, as well as an educated shake of the foils.

Basically you want the headstay reasonably "tight" and still maintain a proper spar shape (again subjective). Spar shape and headstay tension are directly controlled by backstay tension.

And, of course, gauge tension is just the starting point, you need to sail the boat to truly tune it.

Bob

[Brian Duff]

The length of the headstay is adjusted to correct sailing characteristics of the boat. Generally at a rig tune this is not adjusted. A sail tune is required to dertermine if the headstay length is right.

The staysail adjusts the bend of the rig, not the rake, so that matters too, requires sailing to determine correct setting.

does that help?

tension of forestay is set by backstay, IFS by runners

[rcassano]

Very helpful! Thank you. let me give this a try and see how she sails.

[Brian Duff]

if you find a lot of weather helm, try bending the rig more (tighter backstay/ tighter IFS and forward lowers) or raking the mast aft more (longer forestay).

IF the boat doesnt point well try tighter backstay (forestay) but about a foot of forestay sag is acceptable for the usual cruising headsails, less is better there though...depending on sail cut.

[Ian McColgin]

I don't understand Brian Duff's response. Normally moving the center of sail effort aft increases weather helm.

I am not a big advocate of fooling about with mast rake to solve a weather or lee helm problem until one is sure that the boat is floating correctly fore and aft. Many boats with a rep for wicked weather helm are really just a bit down at the head. Since water is ever so much denser than air, it takes less movement of lateral resistance to get near balance than it would moving the sail area. Both are important, but think of hull trimming ballast as the coarse adjustment and sail fore and aft as fine.