swing rigs

One of our members was experimenting with swing rigs on his mini40. He checked out the set up on some Marblehaeds and IOM’s over here, but after he built one, he didn’t get the rig to work properly. In drifting conditions it was hopeless, 5-7 knots the boat was a rocket ship, 8-12 knots was geting knocked off easily and above this was totally useless.

My question is what was he possibly doing wrong. The sails looked terrible in anything over 8 knots, and the boat just wouldn’t tack well and didn’t point. Any suggestions? as I would like to give it a go, but that one put me right off.

Peter

As far as pointing goes some guys rig swing rigs with the tack of the jib and the clew of the main on the same carbon tube(in line with each other-not good) or with the jib pivot on the same tube or in line with the main clew. That type rig won’t point. If you go with a “break back” type that allows the forestay(projected not actual) to intersect the centerline of the boat when the rig is sheeted in for upwind work and the main clew to be 5-10 degrees off the centerline it will point assuming the sails are made well and the daggerboard(s) are right.
You also need to make sure that the rig pivot is correct and that the ratio of main sail area to jib area is correct for a swing rig. I believe that Bantock shows recommended areas for his swing rigs in his catalog.
On main only swing rigs you don’t want more than 19% of total sail area ahead of the pivot point. I’m not sure what it should be for main/jib rigs but I do know that the pivot must be ahead of the aerodynamic center of the rig or it won’t sheet properly.

Doug Lord
–High Technology Sailing/Racing

I don’t think you see any breakback rigs anymore. The did not work too well. I asked Sterne why he didn’t use them and he said there was no difference in pointing. Also he is using a sting-rig where the mast is bent back 10" from vertical and the leech is vertical, luff has a 10" curve. Go to his web site. He uses this because he can make his jib 30 % instead of 25 % of the total sail area. I have his String -rig on his 10R. I believe the first 10R to use one. It sails well in all conditions. Really great in drifters. I have made a lot of swing rigs and did not like the breakback. I am going to put the String rig on Nightmare MK IV tri. I have a standard rig on MKI and the Ernst swing with stays on MKIII. Hanu (Finland)has MKII with the same swing? The sting rig is 1470sq. in. compared to 1392 legal will see what the difference is. The swing rig is mainly a light air sail and tends to nose dive when the wind picks up. Look at the F100 site if still there . As I remember they were all swing rigs and in more than light air. All my rigs were self standing as is the Sting. Ernst are on a peg and have shrouds- stays. I have not put it together yet. He will not help with instructions now that I have the boats. It took a while to figure out it qas not self standing. Hanu confirmed for me. A box full of parts and no instructions is a task.

Hoj, on the swing rigs you use when they are set up for upwind where does the projected forestay fall-to windward of the boat’s centerline or on the centerline?
edit: One more question:where is the pivot on the Sterne rig-at the mast or in front of the mast?
edit-whether you call it break back or whatever if you use a swing rig that brings the projected forestay down on the centerline of the boat with the main clew offset it will point very well…

Doug Lord
–High Technology Sailing/Racing

They are to windward and mathematically they should point better but mine didn’t and Sterne says same. It also brought in a lot of stalling. The jib would not set as quickly and did more flapping than the standard. The jib is rigged normal pivot at 25% of jib boom.If you look at the US-1M and almost evrything else they pivot to windward with the 25% offset . The mast goes into a tube in the hull so this is the pivot point. It is free standing. You can see it on his web site for the Viper Marblehead not 10R. Mine we similar but adjustable with three tubes. I ended up using just one. Mine was his first attempt at a 10R but the balance is perfect in all conditions so far. I still have to sail against the Nightmare. They are both so fast other members are afraid to sail them. I have tried different pivots on the US-1M and others but they wouldn’t go wing and wing when the forestay was brought to center line.

The rig I’m thinking of would allow the forestay to be on the centerline with the main clew off the center line about 8 degrees and it would point well and handled well in all respects. The princible(except for the swing pivot part) is the same as using a radial jib fitting that definitely improves windward performance as compared to a “normal” jib pivot.The rig I’m thinking of was probably a later variation of John Elmaleh’s “breakback” rig.
How is Ernst’s rig set up for the Nightmare?

Doug Lord
–High Technology Sailing/Racing

I built my first swing rig while doing a lot of drawings and trying to keep the angle of the sails at 45 degrees to the wind and maintain the slot. I almost had it but found a book by Manfred Curry with a picture of a boat on the Solent river in 1928 with a swing rig. Eureka. I have been playing with swing rigs since 1982. I tried John’ breakback when it was shown in AMYA. I had more problems than benefits. Ernst’s is decked stepped and under the mast on mine but offset on Hannu’s. It has three shrouds attached to the mast in the front,just above a diamond rig. It was all apart I am trying to figure it out. It is a puzzle.

Thanks for the info, Hoj. It’s been a while since I fooled with them; they won’t workon my boats…

Doug Lord
–High Technology Sailing/Racing

Hi,
I was “given a Go” with a swing rig M class once, found it very hard to sail, not at all like a normal Rig.
If starting out with a swing rig, it would be a good idea to let someone who had sailed one and knew how to set it up,they are rather different to handle - - my opinion!!.
John.
Edit;<font color=“green”>The boat was set up and had just finished Racing</font id=“green”>