Fore stay tension with furler on

[ed stack]

Recently got our Pearson 32 back in the water after an engine refit (5411 out, 3YM20 in) along with replacement of the fore stay and furler (Schaefer 1100). On the shakedown, after we departed the yard, noticed the rigging was pretty lose (side stays tight, fore and back stays noticeably slack). Fore stay was so loose, it could be seen to sway side to side. Needless to say, we didn't raise canvas, and motored to home port, where she's now on the hook. New engine worked really well!

So day after returning home, I went back to the boat on Sunday to adjust the rigging. I was able to get all side stays and shrouds similarly tight, and mast is centered. Back stay is also tight, and mast has maybe a 4-5 degree bend aft. My fore stay is now pretty much as tight as I can get it.




My question is this: with the furler reassembled, I can still deflect the stay ~5 degrees forward/aft is this normal?

Thanks for any feedback.

ed

 

[shemandr]

5 degrees? Can you give an amount in inches that the midpoint on the forestay deflects? It sounds like a lot but a catenary principle is that there is an amount of sag that is dependent on the length of the span and not on the tension of the span (Engineers please correct or help me out here). So, you can't tune out all of the sag. But it's very possible the forestay was cut too long. I know of a boatyard that cut a mast too long. It happens. Is the forestay turnbuckle maxed out?
When you say the mast has a four to five degree bend do you mean the mast itself is bent or do you mean the inclination of the mast relative to the hull is four to five degrees slanted? If its the latter, then you probably can't take up the forestay slack any more and you're forestay is too long.

 

[RichH]

Forestay tension is adjusted by backstay tension.
If you set your backstay to approx 15+% tension that will be the 'normal' for most cruising boats.

To set the correct 12-15% tension in all the other stays, go to: http://www.riggingandsails.com/pdf/selden-tuning.pdf and if you dont have a tension gage, search for: setting up tension manually / without a gage by using a 'meter stick', in that manual.

hope this helps.

 

[ed stack]

Hi shemandr,

Thanks for the response. Let me try to answer your questions.

5 degrees? Can you give an amount in inches that the midpoint on the forestay deflects?

I would say if looking at the furler drum assembly, there less than an inch movement forward and aft. Not quite sure how much that would translate to at the stay midpoint (sag). What i meant by the 5 degrees was the +/- movement observed in the drum, assuming a center line from the bow chain plate/shackle pin to the mast head. Does this make sense? And the fore stay turnbuckle is nearly maxed out (maybe 4 turns left?)


When you say the mast has a four to five degree bend do you mean the mast itself is bent or do you mean the inclination of the mast relative to the hull is four to five degrees slanted?

I meant the the mast appears vertical from the deck through the spreaders, but from there there's a 4-5 degree bend, or curve. I seem to remember that too much mast bend can lead to lee helm?

ed

 

[ed stack]

Hi RichH

I don't have a tension gauge, in part as the guys in the yard very much deemed such unnecessary. As we don't race much, I never bothered. Am I being unrealistic relative to the gauges value?

In the short run, I'll try the meter stick approach Selden describes, even though my spar is an old and rare Schaefer spar!

Thanks.

 

[RichH]

Ed - A too loose forestay can make a boat aggressively and unduly heel, and with greatly reduced capacity to 'point'.

The tension is that forestay affords a predictable structural 'platform' upon which your jib 'rides'. Most cruising headsails are designed/cut with the sailmaker 'assuming and expecting' that that forestay is at about 12-15% of wire tension. Such tension will usually result in adequate sail functionability as the sailmaker designed into that sail.

Tension, fairly precise tension, in the rigging; therefore, is more important for sail performance (aka: a safety issue for the 'cruiser' in the higher wind ranges) than 'holding the rig up' .... and one shouldnt really 'guess' about those tensions for performance and the safety of boat handling/sailing.

A too loose forestay can be a safety issue when sailing especially in the higher wind ranges because it can cause a boat to aggressively heel over while 'skidding sideways to leeward' (felt as a large amount of 'weather helm') and with sometimes a severely reduced ability to 'point'.

;-)

 

[rfrye1]

I have a related question for Hunter B&R rigs. On my H376 I get some "pumping" action in the head sail when sailing close into the wind. Mostly over 15 kts. I usually reef the big main about 15-17 kts to keep her flatter and she handles better. But still the pump.

Could it be forestay tension? Or my sail trim? Both? Since I don't have backstays, I'd have to tighten the fore.

Thanks. Bob

 

[ed stack]

RichH,

I appreciate your sentiment. When we had our J24, I was pretty zealous about setting all the rigging to the one-class specs. Gave the tensioner with the Jboat to the new owner.

With the larger Pearson, I could (and will) check every stay but the forestay, since the riveted foil and furling drum preclude access to all but the turnbuckle. In this instance, how would one verify whether the stay is at the right tension?

At this point, if the movement I can observe is not normal, which with sag I wonder, then what should be done? Is this a case where the yard should have correctly tensioned the stay with the foil on but without the drum assembled? If so, that seems like an inordinate process every year, when we step the mast for transport and storage.

ed

 

[Douglast]

I love my Loo's gauge...very affordable..a couple half turns adjustment does make a significant change on tension with no real change on the "feel".

They sell them on this sites store.

 

[RichH]

RichH,

I appreciate your sentiment. When we had our J24, I was pretty zealous about setting all the rigging to the one-class specs. Gave the tensioner with the Jboat to the new owner.

With the larger Pearson, I could (and will) check every stay but the forestay, since the riveted foil and furling drum preclude access to all but the turnbuckle. In this instance, how would one verify whether the stay is at the right tension?

At this point, if the movement I can observe is not normal, which with sag I wonder, then what should be done? Is this a case where the yard should have correctly tensioned the stay with the foil on but without the drum assembled? If so, that seems like an inordinate process every year, when we step the mast for transport and storage.

ed

The backstay 'reacts' with the forestay, ..... Just tension the backstay to 15%+ and the resultant tension in the forestay will be close to that value. Retune the tensions in the sequence outlined in the Selden rigging manual. ;-)