Genoa Trim Question

[johnsilver2]

One for the sail trim experts?

I occasionally sail with just the genoa up. Yesterday was an example. It was blowing quite hard and for the trip back to Conwy from Moelfre I opted to use just the genoa as the wind was either on or abaft the beam and being single handed this was the easy option.
I am always suprised at the amount of weather helm I get from the genoa and I suspect this could be caused by incorrect trim hence my request for advice from the sail trim experts out there.
The facts:-
My boat is a Rival 31
Roller reefing 150% genoa in good condition.
Halyard was set tight.
Wind speed 25-30kts gusts of 40kts (not sure how accurate my anemometer is but it was blowing very hard at times)
Reefed with a couple of rolls.
Foam luff in genoa.
Sheet car well aft, most probably too far after reefing causing a lot of twist.
No danger of rounding up but I had to work quite hard on the tiller at times to keep her way from the wind.
Sailing at 6 to 6.5 kts on the log and 7+ on the GPS, neap flood with me on the way back to Conwy.
What can I do to reduce the weather helm in this situation please?

Regards.............Andrew

 

[bbg]

How much was the boat heeling? As a boat heels the underwater profile changes, and the underwater shape can make the boat want to turn - typically into the wind.

 

[wotayottie]

Reef more. Your's is an old fashioned rig with most of the power in a large genoa and less in the main. With 40kn true you need much less than the 130% or thereabouts that you would have left after just a couple of reefing turns. You should be down at about no 3 size.

On my boat, if I have more than 10 degrees of wheel ( which is about 10 degrees of rudder) I dump the main in a gust or reef if the wind is sustained. Your rudder acts as an enormous brake so you dont go faster by having the boat overpowered anyway.

 

[johnsilver2]

Good point. Yes we were heeling quite a bit at times and I suspect the old Rival hull is not the best at straight line tracking when heeled.
Comments from Rival owners..........?
At the time I had thought at I should reef down further to keep her more upright but having to go out and move the genoa car put me off as I was only a couple of hours back to the shelter of Conwy mountain! Also a deep reef means unreeving the sheet from the car and passing it forward of the stantion, a real pain in the #@*! - after tack and then a tack back.

Regards..............Andrew

 

[CFarr]

Reef more. Your's is an old fashioned rig with most of the power in a large genoa and less in the main. With 40kn true you need much less than the 130% or thereabouts that you would have left after just a couple of reefing turns. You should be down at about no 3 size.

On my boat, if I have more than 10 degrees of wheel ( which is about 10 degrees of rudder) I dump the main in a gust or reef if the wind is sustained. Your rudder acts as an enormous brake so you dont go faster by having the boat overpowered anyway.

+1
Exactly as I have found when sailing on genny alone.
reef down, sail flatter, less weather helm, same speed!

 

[johnsilver2]

Yes, that all makes sense. I certainly would have reefed down further if I was going further. From my previous reply you will see why I was reluctant to reef further in this situation. It is only 15 miles from Moelfre to Conwy and I was having a blast sailing at 6.5 knots in the old Rival (now 43 years old and still going strong!)
I suppose reefing more would have moved the centre of effort forward and helped to counter the weather helm caused by the hull when heeled?

Regards.............Andrew

 

[Twister_Ken]

Surprised that sheet lead seems to be through the guard rails (if you have to re-reeve the sheet to move the car position). Doesn't sound right to me, and I've never sailed a boat where this was the case. Have you got that right?

A winter project might be to look at rigging a tackle on the sheet cars, so that you change their position from the cockpit.

 

[johnsilver2]

Yes, the genoa track is only a couple of inches in from the toerail so the sheet has to go under the lower guardwire. A stanchion is part way down the track so deep reefing the genoa without passing forward of the stanchion would put a lot of strain on the stanchion base. This is OK most of the time but a pain to sort out when required as things are generally a bit wet and wild when you need that deep genoa reef!

Regards...............Andrew

 

[johnsilver2]

Both offspring are starting university this month so all discretionary boat expenditure is suspended otherwise a replacement genoa car set up would be a possible option! I could even put a new track inboard so as to pass the sheets over the guard wire.
Comments from other Rival owners reading this?

 

[RobbieH]

Yes, the genoa track is only a couple of inches in from the toerail so the sheet has to go under the lower guardwire. A stanchion is part way down the track so deep reefing the genoa without passing forward of the stanchion would put a lot of strain on the stanchion base. This is OK most of the time but a pain to sort out when required as things are generally a bit wet and wild when you need that deep genoa reef!

Regards...............Andrew

On my Arpege the genoa sheet bears heavily on the upper guardwire as soon as we free off a bit, but we need to sheet inside the guardwire for closehauled. I've got Goiot cars (actually Barton cars running on a Goiot t-track). They have a wide sheave which lets me reeve two sheets. I normally have a lazy sheet with a clip on it reeved outside the guard wires that I can use to release the strain on the closehauled sheet as soon as we free off.

It's pretty quick to transfer the strain from the inside to the outside sheet -
having primary and secondary winches helps. Plus a cleat between them if it is needed to swap line on primary winch onto secondary or vice versa.

I've also got a second car running on each track (forward of the normal genoa car) that I use to rig a twing to the lazy sheet when the boat goes off the wind. Then I don't need to go forward to change the sheeting point by shifting the genoa car if it is just a minor tweak in position. I can leave the genoa car at the farthest aft closehauled sheeting position and use the twing to bring the sheeting position forward. Not much strain on the twings compared to the genoa sheet especially when off the wind.

I don't have cars that can be hauled under load and it would be a lot of $$$ and effort to change so the twing solution works for me - at the expense of some more string in the cockpit

 

[bbg]

On my Arpege the genoa sheet bears heavily on the upper guardwire as soon as we free off a bit, but we need to sheet inside the guardwire for closehauled. I've got Goiot cars (actually Barton cars running on a Goiot t-track). They have a wide sheave which lets me reeve two sheets. I normally have a lazy sheet with a clip on it reeved outside the guard wires that I can use to release the strain on the closehauled sheet as soon as we free off.

That's the way to do it. In conditions that are deteriorating you can have both attached, if you think you will be on one tack for a while.

 

[kds]

What is a "twing" - a Barber hauler ?
Ken

 

[RobbieH]

What is a "twing" - a Barber hauler ?
Ken

http://l-36.com/twing.php


The glossary definition given at the top of the page says:Twing - Similar to a Barber hauler, a twing adjusts the angle of sheeting. The difference between a twing and a Barber hauler (also barberhauler) is that a Barber hauler adjusts the jib sheet angle athwartships where a twing adjusts the vertical angle of the jib sheet. Actually, a Barber hauler is named after Jim Barber who was the first to use it to pull his jib sheet out. It has also been called an outhauler. Another control, more popular now than an outhauler pulls the jib sheet in toward the center of the boat. Big time racing boats like TP-52's use these. I like to call them inhaulers but people use the term Barber haulers to describe them as well. Said another way, a Barber hauler is equivalent to changing the location of your jib track closer or further from the centerline of the boat. A twing is equivalent to sliding the jib car along the track (but a lot easier to do).

 

[bbg]

A friend of mine was surprised to hear me refer to inhaul and outhaul for the jib sheet. On his boat the are called and marked as inf**cker and outf**cker.

 

[jwilson]

How much was the boat heeling? As a boat heels the underwater profile changes, and the underwater shape can make the boat want to turn - typically into the wind.

True, but this is not the major cause of weather helm as you heel more. The big effect is from the lift vector from the sail being way off-centre as the centre of the sails moves outboard with heeling.

Reef a bit more. But at least a Rival can steer straight well heeled. Done quite a few miles on a Rival 34, including some heavyish weather. Most modern boats (like my present Jeanneau) would absolutely force you to reef more. But then your Rival doesn't have a huge double berth.

 

[westhinder]

True, but this is not the major cause of weather helm as you heel more. The big effect is from the lift vector from the sail being way off-centre as the centre of the sails moves outboard with heeling.

Reef a bit more. But at least a Rival can steer straight well heeled. Done quite a few miles on a Rival 34, including some heavyish weather. Most modern boats (like my present Jeanneau) would absolutely force you to reef more. But then your Rival doesn't have a huge double berth.

Fully agree. Sailed a Rival 34 for over 20 years and not once did she become uncontrollable when overpressed. She would heel more and accelerate. Reaching in boisterous conditions under genoa alone never was a problem as she responded well to her rudder.
As far as your sheeting arrangement is concerned, that appears cumbersome. We always led the sheets over the upper guardwire, even though that meant that the sheet put pressure on the wire. We never had any ill effects on guard wires or stanchions, only some chafe on the sheets, but nothing dramatic. Our setup enabled us to adjust the genoa sheet cars in all circumstances.

 

[RobbieH]

.
As far as your sheeting arrangement is concerned, that appears cumbersome. We always led the sheets over the upper guardwire, even though that meant that the sheet put pressure on the wire. We never had any ill effects on guard wires or stanchions, only some chafe on the sheets, but nothing dramatic. Our setup enabled us to adjust the genoa sheet cars in all circumstances.

If you can get the clew further outboard when reaching the sail sets better especially if is a deck sweeping genoa - going over the guardwires both lifts the clew (more twist) and pulls it inboard both usually undesirable on a reach. So I use a lazy sheet for that reason as much as cutting down on chafe. If it is just a few minutes offwind then I wouldn't bother, but when you are talking about hours or days on the same tack then it seems like not a lot of extra work.