Twistle rig

[prv]

That's correct, if you look carefully at the fitting there is no way the flanges can overlap

I don't understand that.

Take your second picture, in the original post. Imagine taking the right-hand (in the picture) "wing" and rotating it 180 degrees so it's pointing upwards. Leave the left-hand wing where it is. Looking at it from the same angle as the photo, the whole fitting would now be shaped like a letter N, yes?

Then push upwards on the left-hand wing and downwards on the right hand wing, and the N will flatten until the outer ends of the wings touch the central part and can go no further.

That's what I'm talking about, though oriented horizontally when on the boat, rather than vertically as in the picture.

Pete

 

[LadyInBed]

Is there any advantage in having the 'lash up' in the video over having a fixed eye each side of the mast?

 

[Boo2]

Is there any advantage in having the 'lash up' in the video over having a fixed eye each side of the mast?

My understanding, through reading around, is that the motion of the joint of the poles is what gives the twistle rig its better characteristics in respect of reducing boat roll cf a spinnaker. I think fixing the inboard pole ends wrt the mast would cancel that advantage.

Looking forward to someone who knows something about it correcting or confirming this...

Boo2

 

[john_morris_uk]

Is there any advantage in having the 'lash up' in the video over having a fixed eye each side of the mast?

Hmm - 'lash up' might be termed a derogatory comment - but assuming you don't mean it in a derogatory way, then yes there is an advantage according to all Twistle Rig users. We are going to rig for a Twistle rig when we sail down the trades. Its got lots of advantages over flying a kite shorthanded.

My understanding, through reading around, is that the motion of the joint of the poles is what gives the twistle rig its better characteristics in respect of reducing boat roll cf a spinnaker. I think fixing the inboard pole ends wrt the mast would cancel that advantage.

Looking forward to someone who knows something about it correcting or confirming this...

Boo2

That's always the theory. From a friend whose sailed with the rig, he says it really does help reduce rolling. When I last sailed down the trade winds, I used boomed out genoa and main with preventer. You try to get used to the rolling and I guess that nothing will prevent it altogether. Even ships of thousands of tonnes roll sometimes (albeit in a rather sedate fashion).

 

[Tomahawk]

Sorry to show my ignorance..

But what is a twistle rig?.. Don't think I have ever seen one?

 

[Dave100456]

Sorry to show my ignorance..

But what is a twistle rig?.. Don't think I have ever seen one?

Read the posts : number 15 has a video to explain!

 

[KellysEye]

>Take your second picture, in the original post. Imagine taking the right-hand (in the picture) "wing" and rotating it 180 degrees so it's pointing upwards. Leave the left-hand wing where it is. Looking at it from the same angle as the photo, the whole fitting would now be shaped like a letter N, yes?

Without the poles on yes it can be shaped to an N, however with the poles it doesn't do that, the flanges never goes to more than thirty degress as the boat rolls.

>From a friend whose sailed with the rig, he says it really does help reduce rolling.

Yes it noticeably reduces the rolling, the reason is the poles are free flying and not attached to the mast. With a pole(s) attached the the mast and to the sail(s)/spinnaker as the boat rolls the sail(s)/spinnaker pushes the mast and the mast pushes the sail(s)/spinnaker. Which increases the roll.

 

[Tomahawk]

Read the posts : number 15 has a video to explain!

Data limit = no watching Utube..
Will look later when I have more data.

 

[Pete7]

Sorry to show my ignorance..

But what is a twistle rig?.. Don't think I have ever seen one?

Twin head sails with two poles, however, poles don't connect to the mast but instead each other with a joint which allows some movement in all directions. The picture from Smackmans video shows a later variant with a rope crucifix supported with up and down hauls in addition to the poles on each side. In the picture the poles have crossed each other and the leather patches are there to reduce wear.

Pete

 

[LadyInBed]

Hmm - 'lash up' might be termed a derogatory comment - but assuming you don't mean it in a derogatory way,

A correct assumption

then yes there is an advantage according to all Twistle Rig users. We are going to rig for a Twistle rig when we sail down the trades. Its got lots of advantages over flying a kite shorthanded.

Yes, I am a short handed Twistle Rig user, but I attach the poles to eyes on the mast.

From a friend whose sailed with the rig, he says it really does help reduce rolling.

That set up (note change of term from lash up) may well also help to reduce rolling.

I was told that an air gap between the two luffs help to reduce rolling, so set mine in that fashion, genoa on roller and a hank on sail on an inner fore-stay (about six inches air gap which you can see in the pic). This works well and I get very little rolling, and that's with a bilge keeler!
There wasn't a lot of wind in this shot and I was a bit off from dead down wind so I didn't need the second pole, but I have used it ok with two poles in a F6.

 

[john_morris_uk]

A correct assumption

Yes, I am a short handed Twistle Rig user, but I attach the poles to eyes on the mast.


That set up (note change of term from lash up) may well also help to reduce rolling.

I was told that an air gap between the two luffs help to reduce rolling, so set mine in that fashion, genoa on roller and a hank on sail on an inner fore-stay (about six inches air gap which you can see in the pic). This works well and I get very little rolling, and that's with a bilge keeler!
There wasn't a lot of wind in this shot and I was a bit off from dead down wind so I didn't need the second pole, but I have used it ok with two poles in a F6.

Very nice - but with respect its NOT a Twistle rig. I humbly suggest you are running what most people would call twin boomed out headsails. In the picture you appear to be running one boomed out headsail and one set free. Its a conventional tradewind rig and perfectly acceptable for what it does, but the Twistle rig essential feature is that the poles are NOT clipped to the mast but to each other and suspended between uphaul and downhaul.

 

[Pete7]

Wouldn't it be easier to use a pair of windsurfer mast bases back to back to give a universal joint, which means you could then use old windsurfer masts as the poles. Just a thought.

Pete

 

[Chalker]

The windsurfer mast base idea looks good to me. Not sure about the windsurfer masts as I broke a mast when used as a whisker pole.
Will be taking a look at the bases.

 

[LadyInBed]

Very nice - but with respect its NOT a Twistle rig.
I humbly suggest you are running what most people would call twin boomed out headsails.

I can live with that, but Twistle rig is a lot easier to say

In the picture you appear to be running one boomed out headsail and one set free.

Yes, I did say
"There wasn't a lot of wind in this shot and I was a bit off from dead down wind so I didn't need the second pole,
but I have used it ok with two poles in a F6."

Have you any views on the 'Air Gap' theory?

 

[KellysEye]

I forgot to say why the flanges can turn ninety degrees. When you set up the joint you clip the uphaul and downhaul on and level it with the clews. Then you clip the poles to the bowlines on the sheets. Obviously you can only do that if the flanges turn ninety degrees. Once the sails are out the whole joint is aligned.

>But whatever the magnitude of the compression, it always pushes the end of the poles together and no articulated system can hold them apart. It will always 'jackknife' on itself and then graunch against themselves.

That doesn't apply to the joint I showed in the pictures, there is no way they can get close together because of the distance between the flanges, let alone graunch. Have another look at the pictures and you will se what I mean.

 

[john_morris_uk]

I can live with that, but Twistle rig is a lot easier to say



Yes, I did say
"There wasn't a lot of wind in this shot and I was a bit off from dead down wind so I didn't need the second pole,
but I have used it ok with two poles in a F6."

Have you any views on the 'Air Gap' theory?

My theory on the air gap theory is that its a made up theory - then all theories are made up so the real answer is I don't know. I can't see any logical explanation to make it work.

The Twistle rig anti-roll theory seems to make sense and lots of users say that it works...

 

[LadyInBed]

the real answer is I don't know. I can't see any logical explanation to make it work.

I had better tell my boat to roll a bit more going down wind under twin head sails then

I don't know if it is a similar principle, but don't parasail spinnakers and parachutes use air gaps to help stability?

 

[john_morris_uk]

I had better tell my boat to roll a bit more going down wind under twin head sails then

I don't know if it is a similar principle, but don't parasail spinnakers and parachutes use air gaps to help stability?

You're a funny man.

I hope your boat doesn't roll too much going down wind but you won't know whether it rolls even less using a Twistle rig unless you try it.

If you think the air gap is helping, who am I to contradict you? You might very well be right and I might try it myself.

 

[KellysEye]

>My theory on the air gap theory is that its a made up theory - then all theories are made up so the real answer is I don't know. I can't see any logical explanation to make it work.

It seems to me that a gap between the sails would simply let air through and thus reduce the power of the sails. I can't see any benefit.

 

[LadyInBed]

It seems to me that a gap between the sails would simply let air through and thus reduce the power of the sails. I can't see any benefit.

As I suggested above - parasail spinnakers and parachutes have air gaps
I believe it is to help stability, I seem to remember reading that early parachutes could not be controlled until someone put air vents into them.
Note - Just googled it and found this:
"Unfortunately, Garnerin's parachute erratically swung back and forth (oscillated) as air first spilled out of one side of the parachute and then the other. To prevent this from happening, other early parachute designers added a vent or hole at the top center of the parachute. The vent allowed some of the air to escape and reduced most of the oscillations. This made the parachute more stable (helped keep the parachute along the same path)."