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Fast but non-planing keelboats like Solings, Stars, Dragons, are tilting the mast forward when running downwind.  

Last weekend I’ve done it myself on a Dragon, mainly because the guy who lended it to me told me so, and yes, it definitely was faster.

…But why? I thought it’s all about wind resistance when going ddw and projected sail area actually gets smaller (a little) when you tilt the mast.

:huh:

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They call that fraculating.  There is a thread on it here: 

 

I don't know about making a boat faster, but you definitely have better control and less rudder movement downwind when the breeze is up as the sail plan is more pulling the boat than pushing it.

Most of the frac rig boats here do it especially the Dash 34s.  There is an old Hotfoot 30 here that has the mast and rig set up so the mast can pivot about the mast step with a block and tackle system to pull the mast forward with a sliding collar.  With that they can pull the mast tip forward about 4 ft

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5 hours ago, 12 metre said:

They call that fraculating.  There is a thread on it here: 

 

I don't know about making a boat faster, but you definitely have better control and less rudder movement downwind when the breeze is up as the sail plan is more pulling the boat than pushing it.

Most of the frac rig boats here do it especially the Dash 34s.  There is an old Hotfoot 30 here that has the mast and rig set up so the mast can pivot about the mast step with a block and tackle system to pull the mast forward with a sliding collar.  With that they can pull the mast tip forward about 4 ft

You list the exact reason that forward tilt is faster downwind.  Less rudder required for control means less drag = more speed.

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Those pics look more like keel pivot parts. Most minis have swept back spreaders so anything more that a rotating rig (protos only) seems unlikely. In the case of 965 this boat has a conventional rig, here's a pic 

ob_6d2aa8_20190308-131811.jpg

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Rig forward gets a bunch of weight forward (fast in light air), less rudder movement (always fast), more separation between spinnaker and main (always fast), and in theory can change the direction of flow on the mainsail in positive ways.

Below is a modern 6 meter, on our next boat we took this concept quite a bit further but can't find a pic just now.

FB_IMG_1497976223562.jpg

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15 minutes ago, ctutmark said:

Those pics look more like keel pivot parts. Most minis have swept back spreaders so anything more that a rotating rig (protos only) seems unlikely. In the case of 965 this boat has a conventional rig, here's a pic 

ob_6d2aa8_20190308-131811.jpg

ok , my fault.

I did recall that a few years the #965 skipper was worried that while adjusting back stays, the rig would fall down, I assumed the boat had rotating mast foot type. 

How does mast foot look like for conventional rig? would it allow some degrees tilt? As the carbon mast is quite stiff compared with alu.

 

Re pics in my post, indeed it is keel pivots.. Axel said keel pivots and mast foot. I had to choose :D

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21 minutes ago, troll99 said:

ok , my fault.

I did recall that a few years the #965 skipper was worried that while adjusting back stays, the rig would fall down, I assumed the boat had rotating mast foot type. 

How does mast foot look like for conventional rig? would it allow some degrees tilt? As the carbon mast is quite stiff compared with alu.

 

Re pics in my post, indeed it is keel pivots.. Axel said keel pivots and mast foot. I had to choose :D

For a conventional rig the mast heel is likely a simple G10 plug into the bottom of the mast tube which might have a little curvature to allow mast flex- The plug would sit on a tube or post of some sort to hold it in position. The construction pics of 965 appear the mast is deck stepped. 

 

One of the craziest mast forward setups was the 50' Numbers. Had it explained that the mast was held in a cup by struts from the deck and the whole lot was designed to pivot at deck level. When the mast was vertical the cup sat on a plate to reconcile the runner/forestay loads but downwind the cup floated in space. 

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In the past I read an article about the theory on why this works. when going ddw, there's no flow over the main. It's completely stalled. If you cant the rig forward, you get some airflow from the foot up to the top of the main... which generates a force straight downwind. Dunno if that's actually the case in rl.

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Ok, I've read the fraculaton thread. As fas as I understand it, fraculation just means letting the curve out of a bent fractional rigged mast and then a little more? What I am talking abut is tilting the whole rig as it is about 10 to 15° forward.

In the dragon, the mast is stayed stiff and never alters its curve, at least between 5 and 20 Knots.  (Forward swept diamond spreaders, inline upper and lower shrouds, runners...) It sits on a joint on the bottom, then goes through a slot in the deck, where it is held by two pushers / pullers.

After rounding the top mark, I let go the puller thingie that pulls the mast aft at deck level, release the runner, and finally ease the headstay to tilt the mast forward up to the mark that the rigger had left on the deck. The forestay with the rolled-up genoa stays completely slack for the whole downwind leg. At the leeward gate, I first pull on he puller-after and the middle man tightens the runner. (You have to be very careful with the genoa halyard - if you have it too tight, the whole power of the running backstay will now be transferred not to the forestay but to the genoa luff. Best way to destroy a sail.)

Solings also do this, just differently. They have swept-back spreaders, but the "chainplates" are rather little tracks on deck that let the shroud attachments slide forward and back so the mast can tilt an even bigger angle. 

 

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50 minutes ago, 10thTonner said:

Ok, I've read the fraculaton thread. As fas as I understand it, fraculation just means letting the curve out of a bent fractional rigged mast and then a little more? What I am talking abut is tilting the whole rig as it is about 10 to 15° forward.

Fraculation as described here is just doing the best you can with the rig you have. You are moving the mast tip forward, either by tilting the rig or bending it. Use the tools you have, :)

Solings have a deck stepped mast, so when the backstay is let off downwind, the whole mast tilts forward hinging at its base on the deck, (some of the more adventurous boats let it forward enough that the worry about the mast coming off the step :). )

 

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This is not a new thing, first fraculated back in the early 90s, I was pit, we had the jib halyard marked for the right position....

also, gusts tend to come from above so angling forward gives a (very slight) projection improvement 

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1 hour ago, Mudsailor said:

This is not a new thing, first fraculated back in the early 90s,

That was long after they closed the door on pumping the whole rig forward with hydraulic headstay and backstay.

Late 70s (lol)

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The 12 Meters had arced mast plates and adjustable head stays. So you could really angle the mast head forward of the base.

As said before it induces separation between the main and the kite.

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I"m not sure I buy into the notion of increased separation between main and spin - at least for a symmetrical.

I can see it happening to a very minor degree with an asymm tacked down in place.

But for a poled spin, the pole will rotate with the mast, keeping the spin head and tack in the exact same place relative to the mast I would think.  The leech will twist off a bit if the sheet is left alone - but I don't see the luff moving much or at all.

Or is my thinking muddled here.  If so, can someone explain why? 

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23 hours ago, 12 metre said:

I"m not sure I buy into the notion of increased separation between main and spin - at least for a symmetrical. (...)

I think it really gets down to course and rolling stability. I had to move the rudder considerably less as soon as I flopped he mast. (The Dragon is one of those old-school boats you have to constantly "steer under the rig" to counteract rolling.)

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On 10/5/2019 at 8:40 AM, Schnick said:

Rig forward gets a bunch of weight forward (fast in light air), less rudder movement (always fast), more separation between spinnaker and main (always fast), and in theory can change the direction of flow on the mainsail in positive ways.

Below is a modern 6 meter, on our next boat we took this concept quite a bit further but can't find a pic just now.

FB_IMG_1497976223562.jpg

The no backstay thing can get a bit scary when the rig is wayyyyyyyyyyyyyyyyyyyyyyyyyyyy forward. Requires some very good coordinating on the gybes. Not for the feint-hearted.

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1. stabilizes and straightens the mast ensuring maximum power from mainsail

2. creates separation between main and spinnaker ensuring cleaner air for the spinnaker

3. moves center of effort forward better balancing boat

4. has a tendency to lift the stern out of the water to reduce drag and can limit rudder profile depending on boat

5. keeps the main more stable as gravity pulls the boom forward instead of it "falling" towards center line

6. allows for less twist in the main

7. observably faster in many many fleets (probably the most important reason!) empirical evidence trumps theories!

 

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On 10/7/2019 at 1:51 PM, 12 metre said:

I"m not sure I buy into the notion of increased separation between main and spin - at least for a symmetrical.

I can see it happening to a very minor degree with an asymm tacked down in place.

But for a poled spin, the pole will rotate with the mast, keeping the spin head and tack in the exact same place relative to the mast I would think.  The leech will twist off a bit if the sheet is left alone - but I don't see the luff moving much or at all.

Or is my thinking muddled here.  If so, can someone explain why? 

If you wing on wing the asym (depends on boat as to whether or not that is fast in some conditions), pulling the mast forward helps a lot. 

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On 10/7/2019 at 12:51 PM, 12 metre said:

I"m not sure I buy into the notion of increased separation between main and spin - at least for a symmetrical.

I can see it happening to a very minor degree with an asymm tacked down in place.

But for a poled spin, the pole will rotate with the mast, keeping the spin head and tack in the exact same place relative to the mast I would think.  The leech will twist off a bit if the sheet is left alone - but I don't see the luff moving much or at all.

Or is my thinking muddled here.  If so, can someone explain why? 

The pole  does not rotate with the mast it is set to make the kite efficient, on the soling this generally means it stays level, rather than perpendicular to the mast. The tack can get a little closer to the mast as result, but the clew will move forward. look at the 6m shot just above.

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7 minutes ago, JohnMB said:

The pole  does not rotate with the mast it is set to make the kite efficient, on the soling this generally means it stays level, rather than perpendicular to the mast. The tack can get a little closer to the mast as result, but the clew will move forward. look at the 6m shot just above.

At an even more basic level, hanging the spinnaker in a dead calm from a forward tilted mast means that the foot will be however many feet and inches forward of the mast. If the mast is straight, it hangs against the mast at best. having the mast forward means that at every point along the sail, except the tack, the sail is further away from the mast/main. 

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Funny Story. Myself and a friend both owned Santana 23 daggerboards. We both were very competitive and did everything we could to make our boats faster. A 3rd Santana 23 arrived bot sight unseen from Florida. The boat arrived with a reverse bend in the mast, Needed the backstay on a little to straighten it.  Downwind the farker was faster than both of us. When he released his backstay his prebend the wrong way put his spin forward. My buddy and I decided to try pulling our masts forward with our spare jib halyards and holy crap we were also faster. We later heard a story that the third Santana while in Florida had bent the mast forward by hitting a wave. After observing that his boat was then faster downwind the other Santana 23 guys in his club worked on bending their masts forward as well by plowing into waves. Prob B.S. but funny anyway.

 

I attached a pic of my buddy and me duelling with our S23s. I am the guy behind at this point. Both of us have since moved on to other rides. I miss my S23.

Dualing Santanas.jpg

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5 hours ago, JohnMB said:

The pole  does not rotate with the mast it is set to make the kite efficient, on the soling this generally means it stays level, rather than perpendicular to the mast. The tack can get a little closer to the mast as result, but the clew will move forward. look at the 6m shot just above.

The tack will always be furthest from the mast when the pole is perpendicular to the mast.  The distance between a pole of length L and the mast = L x sin angle to the mast.  Sin angle is max when angle = 90.  Anything else yields a lesser value.

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15 minutes ago, 12 metre said:

The tack will always be furthest from the mast when the pole is perpendicular to the mast.  The distance between a pole of length L and the mast = L x sin angle to the mast.  Sin angle is max when angle = 90.  Anything else yields a lesser value.

Not eery boat has a track for teh onboard end though

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17 hours ago, 12 metre said:

The tack will always be furthest from the mast when the pole is perpendicular to the mast.  The distance between a pole of length L and the mast = L x sin angle to the mast.  Sin angle is max when angle = 90.  Anything else yields a lesser value.

Yup, and the derivative close to 90 is very small, so the change in distance is very small.

Are you trying to understand how the tilting forward increase the separation or are you trying to win an argument that it does not?

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Sick idea: has anybody tried to also tilt (or rather: cant) the mast to the side of the spin pole? Should separate main and spinnaker even better. Then of course one would have to heel the boat the opposite way to bring the center of effort back over the center of the boat (less rudder angle). 

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On 10/9/2019 at 12:05 PM, JimB said:

Funny Story. Myself and a friend both owned Santana 23 daggerboards. We both were very competitive and did everything we could to make our boats faster. A 3rd Santana 23 arrived bot sight unseen from Florida. The boat arrived with a reverse bend in the mast, Needed the backstay on a little to straighten it.  Downwind the farker was faster than both of us. When he released his backstay his prebend the wrong way put his spin forward. My buddy and I decided to try pulling our masts forward with our spare jib halyards and holy crap we were also faster. We later heard a story that the third Santana while in Florida had bent the mast forward by hitting a wave. After observing that his boat was then faster downwind the other Santana 23 guys in his club worked on bending their masts forward as well by plowing into waves. Prob B.S. but funny anyway.

 

I attached a pic of my buddy and me duelling with our S23s. I am the guy behind at this point. Both of us have since moved on to other rides. I miss my S23.

Dualing Santanas.jpg

Those are cool boats, unfortunately the time bomb structural issues have probably doomed most of them.

We fraculated ours and it was definitely faster. I replaced the backstay with  a dyneema line and split 12:1 with a long long throw... the masthead probably went forward 3 feet. If it didn't have that big-ass rudder it would be a broach coach too.

These boats have a deck (or cabin top, really) stepped mast so it can pivot fore-n-aft freely. Rake is limited by their tendency to weather helm.

Total weapon in light air. We beat the fuck out of everything, it should carry a PHRF rating of about 80 in 5 kt winds. Not a bad heavy air boat either, surprisingly; but of course you get waterlined in good sailing conditions and we had to paly keep-away for tactics because we were by far the smallest boat in our class and got killed when being blanketed by, say for example, a C&C 36.

FB- Doug

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