formula 18 upwind: use of mainsheet and cunningham

[carlo]

Hi all,

I have one doubt about how one should manage the mainsail trim upwind on a formula 18 catamaran. Premise: I come from skiffs and therefore my habits are different from those of catamaran guys. Should the helm trim the sheet, and the crew trim the cunni? Is there a difference between windspeeds? With medium breeze (say full, power, double trapping, little depowering needed) my helm insist on me trimming the cunningham with every gust, while not touching the sheet. However, I feel I cannot respond to the gusts fast enough, and my feeling is that I never get "in the groove". suggestions? The videos from the 2010 worlds do not touch this topic....

 

[drew584]

Im of the opinion that in almost every condition that it's faster for the crew to trim the main and and make adjustments o the Cunningham as necessary. Sometimes the skipper can do the Cunningham. There are always exceptions to this but once the crew is on trapeze single trap I find it faster to have the crew trimming the main.

 

[USA 007]

The crew trims the main going upwind. I also have the cunningham led out to the trap wire for the crew. It's easy to adjust both without leaning in.

 

[Tornado_ALIVE]

Both above are correct.......... All tasks with the exception of steering are done by the crew. Helming is a totally consuming job.

I recommend watching this training video -

 

[maritimesailski]

Agreed on above comments:

Crew does main once trap conditions (some people will have diff opinions on when the skip should do main, we always had the skip do main in variable single trap conditions or less, they have a better feel in the light air).

Cunni trim: lead out to crew's trap set, crew can play when needed and skip can as well. Typical delay in feeling the change in cunni is slower then main trim changes, so yes, your feeling of always being out of groove is to be expected if playing the cunni as much or more then main.

One of our signs that we need to touch the cunni: main is being trimmed in and out more then a few inches in puffs and / or skip is needing to drive up and down more then a few degrees to deal with puffs. This tells me (crew) we are overpowered and I'll trim in the cunni a bit (1 number on our mast sticker typically). Over time you get better at it and do end up playing it a lot, but nearly as much as main.

 

[F18 Sailor]

Some of the best teams in the world have the helm trimming the Cunningham from the wire. This is much faster as the crew can concentrate on smooth mainsheet eases/sheets in the bigger puffs. In order for this to work effectively, you really need spinlocks on the mast, standard harken cleats are too difficult to release from the helm position.

I personally find trimming cumminghum, done properly, is faster in certain conditions (smoother wind, less big puffs) than playing main all day. That is just my opinion however and conditions on a race course are always different.

 

[carlo]

Thank you all for the responses!

Everybody seems to support my original idea. I'll try to talk to the helm on the next sortie...

 

[Speng]

I'm of the opinion that the cunny should be nicely trimmed at all times but with a little left on, some guys like it trimmed to the nth degree but maybe that depends on how much facial hair you've got...

 

[bushsailor]

What about main sheet vs traveler. When is main eased and when is traveller droped.

 

[F18 Sailor]

Traveller is only dropped under the following circumstances:

1) You are overstood downwind or while reaching (kite up or not). Be careful easing too far in big waves downwind.

2) Dropped 2-3" upwind if you are maxed out on diamond wires, Cunningham, boards are max up and the mainsheet is constantly being eased. This is usually in consistently greater than 20 kts of breeze.

 

[Bsquared]

I have seen the crew play the traveler on A Cats; leave the main sheeted and work the traveler in big gust conditions. Certainly less belly in the sail while still twisting off the top. Also seems to keep weight outboard better than working the sheet, as traveler has less load and less purchase and no need for as much body movement. I'm not sure I trust my traveler cleat release that much...

 

[F18 Sailor]

It also depends on your traveler setup. I know we would have a hard time with the stock setup on the Infusion Mk. 2 (which I believe is very much the same on other boats) playing the traveler upwind, but in really big conditions the traveler is in the hands of the helm and ready to dump if needed. The same applies when two wire reaching.

 

[neuronz]

Hi all,

I have one doubt about how one should manage the mainsail trim upwind on a formula 18 catamaran. Premise: I come from skiffs and therefore my habits are different from those of catamaran guys. Should the helm trim the sheet, and the crew trim the cunni? Is there a difference between windspeeds? With medium breeze (say full, power, double trapping, little depowering needed) my helm insist on me trimming the cunningham with every gust, while not touching the sheet. However, I feel I cannot respond to the gusts fast enough, and my feeling is that I never get "in the groove". suggestions? The videos from the 2010 worlds do not touch this topic....

I have a friend who is a good F18 crew and we once talked about this question and he said he is doing exactly what you are questioning, never touching the mainsheet upwind and using the cunningham to trim through gusts. He explained to me that they were using an extremely powerful cunningham that was actually bending the mast when rotated and therefore flattening the sail. I believe this is the major difference to skiffs where rig and vang are set and you then use the mainsheet to control power as you have less control over mast bend while sailing.

 

[carlo]

Hi Neuronz,

my cunningham is powerful as well, with a 12:1 purchase, and bends the mast too. My problem is not understanding how it works, it is getting in the groove.

So, while sheeting cunningham bends the mast and opens the top battens without reducing leech tension, my impression is that it cannot be worked as fast as the mainsheet. The consequence is that the theoretical advantage is lost in practice.

I also would like to underline that most skiffs nowadays have square top (or big roach) mains, therefore the cunningham has the same effect on the shape of the sail, and is similarly used.

My helm is definitely a good catamaran sailor: I was not interested in what a good sailor does, but in what the best sailors do. Sometimes there is quite a difference between "good" sailors and pros, as the last 10 % of speed takes 90 % of the effort!

 

[Tornado_ALIVE]

If you want to know what the best are doing...... Crew works the main (primary trimming tool). Crew and skipper make secondary trimming adjustments with the cunningham

Ashby

Brewin

Goodall (note Ashby trimming the cunningham)

 

[Tornado_ALIVE]

BTW, have you tried releasing the cunningham without the main........ It does not release very much until you ease a little main as the luff is under too much load.

 

[Tornado_ALIVE]

Traveller is only dropped under the following circumstances:

1) You are overstood downwind or while reaching (kite up or not). Be careful easing too far in big waves downwind.

2) Dropped 2-3" upwind if you are maxed out on diamond wires, Cunningham, boards are max up and the mainsheet is constantly being eased. This is usually in consistently greater than 20 kts of breeze.

Spot on, also when hove too waiting for a start.

 

[F18 Sailor]

Great photos and excellent point regarding easing of main to dump downhaul. That is another reason why the skipper controlling downhaul can work really well.

The real question is how to sail the boat fast downwind? I have heard from some lighter teams that in flatter water and 12-16kts of breeze going double wire downwind, ala N17, can be really really really fast. This is from a well practiced, top 10 in the U.S team and the skipper has lots of experience trapping downhill on the A. We haven't had the nerves to try it this season or the conditions, though are fairly experienced going double wire upwind in breeze.

I am also curious what teams in AUS etc. are running for trapeze height adjustment on the rear trap?? I know Bundock runs a stock non-adjustable setup as does Ashby from those photos. My issue with this is as crew I can't get low enough on the wire when behind the aft beam downwind. I doubled the length of our adjustable setup on the skippers trap (the one the crew uses downwind) to handle this.