How to trim an asymmetrical spinnaker?

[Lazerbrains]

To be honest, I didn't find assy trim to be that hard once I tried it - when you get it up and flying it all starts making sense once you start making adjustments.

Thomm - my boat is a dispacement hull, so my assy's are only for light winds. My boat doesn't surf and If I can't make hull speed at 10knts with my white sails, I'm doing something wrong.

[barnakiel]

Originally Posted by CassidyNZ

Sorry, don’t get the point. Hand-over-hand? You mean up the mast? Yes, that’s how I do it. Do you mean without a sock? Yes that’s eminently possible but then it’s much harder to douse without a sock especially if the wind pipes up. In the lee of the mainsail? Yes, of course, when that’s possible.

Still don’t get the pole, uphaul, downhaul, tack line, etc. How do you get the pole back? Another, 4th line? Sounds like you need 4 extra winches.

But most importantly, why?

No, you simply fly (unclip) the windward part (the tack) and then pull on the sheet and it spills the wind and floats into the lee of the main. Then you ease the halyard and pull the sail in (douse it).


An assy flown without a pole has only one sheet and it takes only one winch to control. That's the point about assy sails. They are controlled just like jibs or genoas.


How big is the sail? I handle a 600sq ft kite easily, alone, windvane driving, me pulling the spinnaker down.


There are countless videos on youtube - have you looked at these?

https://www.youtube.com/watch?v=ktd14qOyE3o

b.

[barnakiel]

I believe these videos are self-explanatory. It is that simple. Nothing to it.

https://www.youtube.com/watch?v=owJHGbzKSVA

https://www.youtube.com/watch?v=T3bUtq4upHA

[barnakiel]

Originally Posted by rhpike

Ease the sheet until the leach starts to curl at the top of the sail, when you are on a broader angle than a beam reach.

Can you expand on this a bit more?


On my boats, when I eased the sheet, the luff curled, not the leech!


Do you think I may have hoisted my kites inside-out?


barnakiel

[CassidyNZ]

Originally Posted by barnakiel

No, you simply fly (unclip) the windward part (the tack) and then pull on the sheet and it spills the wind and floats into the lee of the main. Then you ease the halyard and pull the sail in (douse it).

Wow! The next time I have 6 people on my boat I’m going to try that.

Even the guy on his own in your next video had to wrestle the sail into his saloon in a huge pile of sailcloth. Then he would have to go down below and repack it into a bag, keeping the luff and the leach together so that next time it is launched, it goes up right. Also, his boat is little bigger than a dingy. My gennaker is twice that size.

Look, I know how that’s done. When I was young and stupid and raced boats for fun with a full crew on board, we did that many times in a race. We would use a large plastic funnel down below to feed the sail through and put elastic bands every 2 metres to enable us to get the sail up behind the main/jib long before the turn mark. Then as the boat turned around the mark, hauling the sheet out stretches the foot out and the wind fills the sail from the bottom, snapping the elastic bands like a zipper and instantly setting the sail. Nothing new here.

But today? On my own? Nah. There’s no beating a snuffer to get a bag down and “packed” for the next launch. Combined snuff-repack-launch time is way better than blowing the tack and trying to manage the sail down below.

[LittleWing77]

Originally Posted by barnakiel

Can you expand on this a bit more?

On my boats, when I eased the sheet, the luff curled, not the leech!

Do you think I may have hoisted my kites inside-out?

barnakiel

Barnakiel!

You are such a smartas$$!
(I love that about you.)

LittleWing77

[barnakiel]

Originally Posted by CassidyNZ

Wow! The next time I have 6 people on my boat I’m going to try that.

Even the guy on his own in your next video had to wrestle the sail into his saloon in a huge pile of sailcloth. Then he would have to go down below and repack it into a bag, keeping the luff and the leach together so that next time it is launched, it goes up right. Also, his boat is little bigger than a dingy. My gennaker is twice that size.

Look, I know how that’s done. When I was young and stupid and raced boats for fun with a full crew on board, we did that many times in a race. We would use a large plastic funnel down below to feed the sail through and put elastic bands every 2 metres to enable us to get the sail up behind the main/jib long before the turn mark. Then as the boat turned around the mark, hauling the sheet out stretches the foot out and the wind fills the sail from the bottom, snapping the elastic bands like a zipper and instantly setting the sail. Nothing new here.

But today? On my own? Nah. There’s no beating a snuffer to get a bag down and “packed” for the next launch. Combined snuff-repack-launch time is way better than blowing the tack and trying to manage the sail down below.

I see your boat 44', ours 26'. Absolutely I would like a snuffer or better yet a furler in any boat where the kite could pull me overboard.


Last time when we sailed a boat with a snuffer though I got (----) off no end by the whole batch hanging up there and now and then banging the mast - making comfortable sleep a near impossibility.


Is there any way to immobilise the hoisted snuffer? Or maybe get a snuffer with a soft edge? (ours was grp)


?


Btw it is true maybe I find this easy as I did this thousands of times. So much as I still mess up now and then, I have a pre-set kind of response for every single thing that can/will go wrong.



What I have never mastered (when dropping the kite alone) is how to avoid the halyard running out too fast. I wish I had some kind of device to adjust how fast the halyard runs. In my case, it quite often runs to fast and the kite touches the water. Especially when the wind gets above 25kts or thereabout. (Our topsides are only 2 ft, though, maybe that's why)



b.

[wingssail]

Originally Posted by dougweibel

I have a 44' catamaran with a 4' bowsprit and a cruising asymmetrical spinnaker in a snuffer. I have not had a spinnaker on a previous boat. I have been having good success launching, retrieving and flying the spinnaker but I get the feeling I'm leaving a lot of performance on the table for lack of knowledge on how to trim it properly. Basically I just play with the sheet, and the tack line to a much lesser extent, to try to keep the sail full and stable.

My tack line is adjustable, but if there is much pressure in the sail I have no good way to do so at present as there is no purchase on it, just a clutch. I'm sure I could rig a couple blocks to take it to a winch if it is worth the effort.

Can someone enlighten me a bit and perhaps help me get from beginner to intermediate in terms of sail trim?

Trimming an asymmetrical spinnaker:

Reach up when setting the spinnaker so the wind fills it, then bear away.

Once flying, ease the sheet until the sail begins to curl at the luff, pull in, ease out. Continue.

Adjusting the tack line: (it should go to a winch)

Pull in harder when reaching, but not so hard that the luff becomes straight, the sail needs to have some curve in the luff.

Ease the sheet and tack line out when going down wind. The sail should float around the front of the boat to windward and into clear air. If you have a tack line to the windward bow you can shift to that line and move the sail to windward. very effective.

Take downs (without sock). Turn the boat downwind and pull sheet the in. The sail will collapse behind the mainsail. Person on the bow pulls the sail down into a bow hatch while second person eases the halyard. as the sail is about half way down, ease the tack line. Steer the boat to keep the collapsed spinnaker directly over the foredeck and behind the main. Be sure to stuff it into the bow hatch or it may blow off the boat into the water. Note: This does not take a racing crew or crazy young people, Judy and I do it, have done it for 35 years. You just get get on with it and do it. If it screws up (it will sometimes) you straighten it out and do it again next time, better.

Photos:

#1 Assym trim, close reaching.

#2 one person dowse (this is with sym kite, but same way with assym.)

#3 If you have more people it can be a lot of fun

[barnakiel]

Originally Posted by LittleWing77

Barnakiel!

You are such a smartas$$!
(I love that about you.)

LittleWing77

You are too good!


hugs,
b.

[FabioC]

By "blowing the tack line", I meant releasing it significantly (you can experiment by how much and mark the line so you can do it reliably), just make sure that your tack line is long enough so you can ease it as needed. The goal is to deflate the sail and "position" it behind the mainsail and ideally on top of the bag (sort to speak), so a crew can grab it and stuff it in easily.

If you just ease the sheet to deflate the sail, the clew will tend to get away from the crew, making their job difficult and unsafe. If you instead ease the tack line, it works much better, since the crew can hold on the sheet without re-powering the sail and recover the sail faster. Also, if you are turning closer to the wind as the sail is taken down, by easing the tack line, the sail will tend to get in the general direction of the bag as the halyard is released (if you really want to be fancy, by easing the proper amounts of both the sheet and the tack line, you deflate the sail and make the life of your crew very easy).

I have seen boats where they truly "blow the tack line" (meaning, they trip the shackle), but I do not understand why, since you have to send a crew to the bow to trip it, you lose control of the sail, and the sail can even twist as it is put back in the bag in a chaotic fashion.

[slug]

Originally Posted by wingssail

Trimming an asymmetrical spinnaker:

Reach up when setting the spinnaker so the wind fills it, then bear away.

Once flying, ease the sheet until the sail begins to curl at the luff, pull in, ease out. Continue.

Adjusting the tack line: (it should go to a winch)

Pull in harder when reaching, but not so hard that the luff becomes straight, the sail needs to have some curve in the luff.

Ease the sheet and tack line out when going down wind. The sail should float around the front of the boat to windward and into clear air. If you have a tack line to the windward bow you can shift to that line and move the sail to windward. very effective.

Take downs (without sock). Turn the boat downwind and pull sheet the in. The sail will collapse behind the mainsail. Person on the bow pulls the sail down into a bow hatch while second person eases the halyard. as the sail is about half way down, ease the tack line. Steer the boat to keep the collapsed spinnaker directly over the foredeck and behind the main. Be sure to stuff it into the bow hatch or it may blow off the boat into the water. Note: This does not take a racing crew or crazy young people, Judy and I do it, have done it for 35 years. You just get get on with it and do it. If it screws up (it will sometimes) you straighten it out and do it again next time, better.

Photos:
Attachment 219282
#1 Assym trim, close reaching.
Attachment 219283
#2 one person dowse (this is with sym kite, but same way with assym.)
Attachment 219284
#3 If you have more people it can be a lot of fun

The beauty of a sock is that it protects the sail , when on deck and during the hoist , from the countless sharp edges and blocks on deck

The sock also allows you to strike the sail , and still keep the sail hoisted

Very valuable when the wind goes flat and you must motor for the next few miles or when threading thru shoals and a tight turn is needed

[barnakiel]

Yep.


two things mentioned but possibly worth re-saying:


1) when you blow the tack, do blow it, doing it half way makes for a very hard take down,
2) if it is very windy, avoid taking down from position ahead of the mast, take it down to a place aft of the shrouds (envelope take down is very good if your main is free footefd).



The kite must be completely depowered and when it is so, the take down is a piece of cake. In light winds the difference is negligible but in more wind you do not want to fight a billowing spinnaker.


b.

[sailor1026]

@dougweibel:
We have a Leopard 40 cat and an asym spinnaker with sock, but no bowsprit, so it's similar to yours. If we're going to be on one jibe, we run the tack line to the windward bow. If we'll have to jibe, we run a tack line to both bows so we can shift the sail's tack to the windward side on the jibe. The bowsprit would be great for close reaching to broad reaching. Deeper angles may be better if the tack line goes to the windward bow. See what works for you.

You don't say you have problems with setting and dousing, so some of the below may be redundant.

The tack line needs to be adjustable so that you can let it out when downwind and trim it with the wind forward. The luff (leading edge) where the tack line attaches should be vertical when trimmed correctly. In general, slack the tack line when sailing deeper and trim it when heading up. The luff should be nearly curling. Slack the sheet until it curls, then trim slightly. Ref: the video Calif.Ted posted.

Tips for Cat asym spinnaker:

* The mainsail can't go out as far in a cat as on a monohull, so the deepest we've been able to go is 150 deg apparent wind angle (AWA). At 150 deg AWA or deeper causes the vortex from behind the main to wrap the spinnaker around the forestay. If a wrap happens, centerline the main, trim the spinnaker lines, and use the engines to spin the boat to unwrap it. (Yup, have had to do this.)

* If you want to go dead downwind, drop the main. However, running jibing angles will often provide better VMG at less than hull speed.

* Put the sock furling line through a block near the deck. When you furl the spinnaker, you're pulled down to the deck. You can also sit or kneel to pull the sock furling line. If you pull it directly, it has a tendency to lift you off the deck and you can quickly find yourself over the lifelines.

* Before bringing the sock down over the spinnaker, turn downwind slightly (150 deg AWA) to blanket the spinnaker behind the main, or unroll the genoa to take pressure out of the spinnaker. It makes it a *lot* easier to bring the sock down.