In-mast furling main windward performance

[Zen Zero]

We entered a friend's cruiser in the Argentario Coastal Race series this winter with the aim of having some fun (and we are!). We didn't want to spend very much money, because we haven't got very much money to spend. So we've done very little to fit her out for racing. She's a Comet 333, which probably doesn't mean very much outside of Italy - just over 10m masthead sloop, 30 years old. And came equipped with roller furling main and headsail.

I saved the trace of our race on Sunday and measured the tacking angles - in 15kt of breeze we were tacking through 98° and were able to keep up with the crowd. Downwind we overhauled most of the fleet with our spinnaker vs their gennakers, and were there in the middle of the fleet at the last leg, straight into a falling wind that died altogether about 500m from the finish. We lost an hour on this leg with respect to the other boats, were last over all and only just managed to finish 2 minutes before time was called. The wind had fallen to 2 or 3 kts and we were only able to tack through 30° that is to say we were sailing 75° over ground to what little wind there was.

I'm sure we can do better without ripping out the in mast furling gear and buying a proper sail.

 

[lpdsn]

Did you do anything specific to trim the sails for the light airs or distribute the crew weight? Even after losing out with your furling mainsail shape, you still should've been able to do better than 75 deg. The trick is to get the boat going at whatever angle to the wind you can then slowly come up whilst slowly trimming in the sails. Any winching should be very slow - amazing how many people even in regular racing fleets struggle to grasp that concept.

 

[Ric]

We entered a friend's cruiser in the Argentario Coastal Race series this winter with the aim of having some fun (and we are!). We didn't want to spend very much money, because we haven't got very much money to spend. So we've done very little to fit her out for racing. She's a Comet 333, which probably doesn't mean very much outside of Italy - just over 10m masthead sloop, 30 years old. And came equipped with roller furling main and headsail.

I saved the trace of our race on Sunday and measured the tacking angles - in 15kt of breeze we were tacking through 98° and were able to keep up with the crowd. Downwind we overhauled most of the fleet with our spinnaker vs their gennakers, and were there in the middle of the fleet at the last leg, straight into a falling wind that died altogether about 500m from the finish. We lost an hour on this leg with respect to the other boats, were last over all and only just managed to finish 2 minutes before time was called. The wind had fallen to 2 or 3 kts and we were only able to tack through 30° that is to say we were sailing 75° over ground to what little wind there was.

I'm sure we can do better without ripping out the in mast furling gear and buying a proper sail.

It's well established that in-mast main reefing on a crewed boat for round the cans racing is a waste of money and a performance disadvantage. Try sailing your boat single-handed over long passages in changing wind conditions (particularly goosewinged, as you might be on a trade wind passage) and you will appreciate it.

 

[dunedin]

Upwind in light winds a curling mainsail is really going to struggle - though a newish laminate sail with vertical battens might suffer less than most.

Upwind in the light stuff a lot of the power, and pointing ability, comes from the mainsail roach / leech. With a horizontally battened conventional mainsail this can be set with the top batten parallel to the boom generating power high up and with little drag. Most furling mainsails end up with a bit of a hooked leech in light winds, which gives lots of drag and little power.
Very differnt downwind, as you have discovered

 

[LittleSister]

Well done!

 

[Zen Zero]

Did you do anything specific to trim the sails for the light airs or distribute the crew weight? Even after losing out with your furling mainsail shape, you still should've been able to do better than 75 deg. The trick is to get the boat going at whatever angle to the wind you can then slowly come up whilst slowly trimming in the sails. Any winching should be very slow - amazing how many people even in regular racing fleets struggle to grasp that concept.

Slackened the back stay, moved the cars fwd, the traveler upwind and tried to convince the helmsman not to come up to windward too quickly after tacking. The crew were fairly distributed in a rather forlorn way, everyone with their own opinion of how to deal with the situation of course, one sitting on the pulpit looking for dolphins, one lying on the coachroof pretending to be asleep and 3 in the cockpit.

When the wind died and we were ghosting with zephyrs we were moving the genoa around by dragging the clew and flipping the mast back and forth (not too quickly!) according to where the windex was pointing the anemometer at the masthead was not moving.

Thanks for your very useful advice

 

[Zen Zero]

It's well established that in-mast main reefing on a crewed boat for round the cans racing is a waste of money and a performance disadvantage. Try sailing your boat single-handed over long passages in changing wind conditions (particularly goosewinged, as you might be on a trade wind passage) and you will appreciate it.

It's not my boat! We've decided to race it this winter, the 3 of us, to have a bit of fun together after the owner suffered a bereavement. And this part of the plan is working.

I realise a furling main isn't ideal for racing, but we're not in a position to change it and we'll go with what we've got.

I'm encouraged by the advice I've received and I'm grateful for it.

Thanks!

 

[anoccasionalyachtsman]

Slackened the back stay, moved the cars fwd, the traveler upwind and tried to convince the helmsman not to come up to windward too quickly after tacking. The crew were fairly distributed in a rather forlorn way, everyone with their own opinion of how to deal with the situation of course, one sitting on the pulpit looking for dolphins, one lying on the coachroof pretending to be asleep and 3 in the cockpit.

When the wind died and we were ghosting with zephyrs we were moving the genoa around by dragging the clew and flipping the mast back and forth (not too quickly!) according to where the windex was pointing the anemometer at the masthead was not moving.

Thanks for your very useful advice

Can't see anything wrong there - did you check that the prop was locked exactly vertical?

 

[Zen Zero]

Can't see anything wrong there - did you check that the prop was locked exactly vertical?

we've got a maxprop self feathering thingy

 

[lpdsn]

Slackened the back stay, moved the cars fwd, the traveler upwind and tried to convince the helmsman not to come up to windward too quickly after tacking. The crew were fairly distributed in a rather forlorn way, everyone with their own opinion of how to deal with the situation of course, one sitting on the pulpit looking for dolphins, one lying on the coachroof pretending to be asleep and 3 in the cockpit.

When the wind died and we were ghosting with zephyrs we were moving the genoa around by dragging the clew and flipping the mast back and forth (not too quickly!) according to where the windex was pointing the anemometer at the masthead was not moving.

Thanks for your very useful advice

Try easing the halyards a little too. You also need more twist in both sails when the wind gets light as the apparent wind is significantly different higher up the mast (same boat speed but more wind aloft - as a percentage much more sigificant than in a normal breeze). Make sure you don't strap the sails in at any stage. Ever so easy to oversheet. You also need a bigger slot to encourage air flow (look up to make sure the slot is not closed at the head of the headsail. Get as much belly as you can in the sails but with the point of maximum draft still being for'd of 50%.

Crew weight for'd and to leeward (knew a mastman who used to stash cans of lager in the forecabin in preparation when he was expecting light airs). Reasoning for weight distribution is to reduce the wetted surface area and reduce frictional drag and to put some shape in the sails through gravity. The crew should avoid interrupting the flow through the slot. All movements should be as gentle as possible. Vibrations from crew movement have a disproprotionate effect on the waterflow over the keel when the boat is otherwise steady. Minimise movement.

The helm/crew need to co-ordinate bringing the sails in as you head up into the wind. Rule of thumb, no matter how slowly you think you're making the changes, the optimum is probably slower. The winch really should go ... click ... click ... click ... as you sheet in

In very light airs (1 or 2 knots) you can strap in the sails. Against the RRS to deliberate rock the boat to propel it, but if any leftover seas or slop are doing it then that is all part of racing.

 

[KellysEye]

We unknowingly chartered a boat with roller furling for Antigua Sailing Week, what we found is because the sail has to be flat to furl the performance upwind is noticeably worse than a curved sail. I would never buy a boat with that fitted.