Topping Lift - Mainsail Trim - Light winds...

[arsenelupiga]

Originally Posted by Sailingcouple13

we can get 55° apparent barely up to 10 knots, but it pinching and slow not efficient. 60° is ideal and we can maintain better shape. Without a long sprit it can be difficult to get proper sheeting angel on a 155 at that tight. Here is a pic of ours at 55°

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L400 is very wide for it's length more than L 440, and especially yours. You have longer bowsprit as well.

So i am guessing will be good above 90 true or 60 app. Below that true angle, jib does same or better.

So that means at 90 true in 10 kn of true wind boat should do 6 knwhich is 1 kn or so better than jib.
At 80 deg boat will do 4 kn in 10 true which is not efficient as jib does better.

and if you can do 55 app, then will go 5 kn in 10 kn wind at 80 true that more or less matches jib.

But will do 7 kn at 90 true in 10 kn wind

[mikereed100]

Originally Posted by meirriba

I am somewhat confused - what do you mean by 'open up the head of the main'?
If you mean opening the leech, it can't be done without freeing the mainsheet. If you free the mainsheet, why do you care about the topping lift? the leech will open anyway.
Can you explain a little more?

In very light air the weight of the boom will tend to pull down on the leech even with the sheets eased. This pulls the leech in at the head just when you want it to 'open up', particularly on a heavily roached main. Tightening up the topping lift lifts the boom and allows the leech at the head to 'open up' and spill the wind. Remember, the OP is talking about sailing in 4 knots of wind, which is pretty heroic. As wind speed increases the pressure of the wind in the sail is enough to keep the boom up and the topping lift becomes unnecessary, as you point out.

[2Wind]

Originally Posted by mikereed100

I've been using the topping lift to open up the head of the main for a long time, as I did with my mono's, but I have never figured out how to get it to work on both tacks on the cat with it's greater roach without first lowering the main a bit to get the leech past the topping lift.

I might be missing your point but....

Just release the topping lift before the tack.
Have enough slack that after the tack it can come freely around to the windward side of the leech (you might need to assist it by going to the boom end and giving it a good flick).
Position the traveller if not centred during the previous tack.
The sheet should not need adjustment assuming you will aim for the reciporical tack angle.
Then tighten up the topping lift to get the desired shape at the head once again.


In general terms, I've found that the upward movement on the boom that is required is only a matter of 8 - 12 inches max, just enough to effectively "unweight" the leech up high and allow for twist. I also have the traveller much further to windward that i normally would do in stronger winds to ensure that the lower 2/3 of the sail is efficient with the slightly looser main sheet. The balance between the three adjustments (lift, sheet and traveller) is key.

[pbr]

A solid vang will give you the same result with a lot less hassle and infinitely more adjustment when it comes to twist.

[impi]

Originally Posted by meirriba

Tight sheet against the topping lift may in fact solve the issue.
However, my main issue in the post was the idea that you may use the mainsail without interfering with the spinnaker and get valuable power from it. Just set it right.
And, one issue more to consider: if you need to take down/roll the spi urgently for any reason, and do not want to start the engine, you will be with the main up at least and not powerless.

We have sailed many miles with the asymmetric and Spinni and found the main usually affects good performance.
Perhaps I am doing something wrong but with nothing but time on my hands and days on end in the oceans - I have yet to find a way to set the main so it does not affect the spinni in dead downwind situations.
Of course with a bit of angle in the right winds, a main can assist the asymmetric, but mostly we feel there is more benefit in sailing these sails without the main.

We crank the topping lift in against the main sheet and then crank in on the mainsheet.
One can 'feel the power' in the boat and we ease off the skirt (tack) when necessary and /or otherwise 'break the tack' using a punch through the T12 fitting. That 'de powers' the entire system immediately.

I have posted these videos before, but for your interest and in case you have not seen them - there is one flying the asymmetric without the main in sting squalls and another on the way to Bora Bora where we punch out the tack with the T12

Touch wood here - we have never felt a threat of the rig being under pressure. In gusting winds we get the sail flying by using the motors to assist in keeping the power off the rig through the sail, and once under way engines come off.

https://www.youtube.com/watch?v=bs3kpZpBaiw

https://www.youtube.com/watch?v=4XQoq9gOURw

[malbert73]

I used to use topping lift in light air to open leech on my old boat. New boat has solid vang which does same thing in raising boom when I release vang tackle. Easier as no snagging leech when we tack.


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[mikereed100]

Originally Posted by 2Wind

Just release the topping lift before the tack.
Have enough slack that after the tack it can come freely around to the windward side of the leech (you might need to assist it by going to the boom end and giving it a good flick).

Thanks. My main has too much roach at the head for this to work, but I have a new main coming soon that has much less and will give this a try.

[meirriba]

[QUOTE=impi;1803446]We have sailed many miles with the asymmetric and Spinni and found the main usually affects good performance.
Perhaps I am doing something wrong but with nothing but time on my hands and days on end in the oceans - I have yet to find a way to set the main so it does not affect the spinni in dead downwind situations.
Of course with a bit of angle in the right winds, a main can assist the assymetric]

My experience is that usually, when your target is dead down wind it pays to tack downwind and not sail straight downwind.
We have measured our VMG downwind while training for racing and actual regattas on various monohulls (J120, Bavaria Match 35 and racing beach cats like f18). The tacking down wind was always faster than running before.
When wind picked up it paid to get lower but never at 180 deg to the wind. If you have a polar table for your boat you can easily find the best angle for going downwind.
There may be boats that behave differently
However, I would suggest to check your speed towards the target by using the VMG function found on most MFD systems.

[2Hulls]

Originally Posted by meirriba

My experience is that usually, when your target is dead down wind it pays to tack downwind and not sail straight downwind.
We have measured our VMG downwind while training for racing and actual regattas on various monohulls (J120, Bavaria Match 35 and racing beach cats like f18). The tacking down wind was always faster than running before.

Yes, for sure on your Nacra, but not on your Lagoon....

There are very few cruising cats that can gybe downwind and make better VMG than dead down wind. There is no shame here - the vast majority of cruising cats are simply too heavy to generate the speed necessary to bring the apparent wind around far enough on the beam to do this.

Dave

[arsenelupiga]

Originally Posted by 2Hulls

Yes, for sure on your Nacra, but not on your Lagoon....

There are very few cruising cats that can gybe downwind and make better VMG than dead down wind. There is no shame here - the vast majority of cruising cats are simply too heavy to generate the speed necessary to bring the apparent wind around far enough on the beam to do this.

Dave

this are polars Lagoon 41, simlar to Lagoon 400. Looks like 140 - 150 true is the answer.

[2Hulls]

Originally Posted by arsenelupiga

this are polars Lagoon 41, simlar to Lagoon 400. Looks like 140 - 150 true is the answer.

Answer to what? If you seriously think your Lagoon 400 can make better VMG gybing downwind vs dead downwind, I invite you to find a race with any other 400 and bet a case of rum as the prize. You'll go thirsty....

Have you ever raced your boat in an organized regatta against other cruising cats? I have and can attest that we've observed several who thought gybing downwind was the "answer" and were severely embarrassed - as predicted. But don't take my word for it. Try it yourself.

Dave

[monte]

Ill take the rum for the rhumb!
BTW. those Polars are dreaming mate! I dunno why polars just cant get it right. Did someone think theyed sell more boats by inflating the figures?
12K boats speed in 22K wind on a beam reach? I Wish!
Actually those figures might be close if not loaded for crusing, engines removed and furniture stripped !:P

[pbr]

When sailing downwind, cruising cats are not much different than most mono hulls , they can and do benefit sailing angles downwind with better VMG up to a certain point of wind velocity which is probably true wind somewhere close to 20knots. The reason that it doesn't seem so at times is when they sail higher angles and jibe, they run the risk of missing a wind shift or sailing to the wrong side, just the same as when sailing/tacking upwind. Most cruisers don't know the difference between a persistent or oscillating wind shift and are probably better off sailing the rumbline. However with the helm in the right hands it can be considerably faster to sail angles offwind both for improved vmg and playing windshifts, and I can assure you that few races have been won without employing the technique.

[impi]

[QUOTE=meirriba;1803608]

Originally Posted by impi

We have sailed many miles with the asymmetric and Spinni and found the main usually affects good performance.
Perhaps I am doing something wrong but with nothing but time on my hands and days on end in the oceans - I have yet to find a way to set the main so it does not affect the spinni in dead downwind situations.
Of course with a bit of angle in the right winds, a main can assist the assymetric]

My experience is that usually, when your target is dead down wind it pays to tack downwind and not sail straight downwind.
We have measured our VMG downwind while training for racing and actual regattas on various monohulls (J120, Bavaria Match 35 and racing beach cats like f18). The tacking down wind was always faster than running before.
When wind picked up it paid to get lower but never at 180 deg to the wind. If you have a polar table for your boat you can easily find the best angle for going downwind.
There may be boats that behave differently
However, I would suggest to check your speed towards the target by using the VMG function found on most MFD systems.

Yes, with you here ... on long passages and in the currents we prefer to relax and go with the flow ... I used to race Tigers and of course tacking downwind was the way to go ... but for our Lagoon on a cruising venture ... its as close to running the rhum possible for us ... but then again, we do follow the currents. Initially we used to tack downwind but in all honesty there was very little to nothing in it on our heavy cruiser ... unless we were sailing Main sail and Genoa ONLY ...

[2Hulls]

Originally Posted by pbr

When sailing downwind, cruising cats are not much different than most mono hulls , they can and do benefit sailing angles downwind with better VMG up to a certain point of wind velocity which is probably true wind somewhere close to 20knots.

I think you're wrong here. Only very light weight boats can benefit from angles downwind vs dead down wind. And certainly not cruising boats. It takes a lot of boat speed to turn the wind to gain any advantage. I raced beach cats for several decades and know how to do it. I have not been able to do it on my cruising cat.

Dave