Is it possible

Dec 7, 2018
186
C&C 27 Mk V Vancouver
to fraculate a masthead deck stepped rig?
I remember reading about how DC did this by removing the wedges on a keel stepped Choate 27 I think it was.
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
I guess you can do it but they are different animals. They work differently. I make the comparison to trees. The masthead is like the mighty oak. Strong and unbending. Made to hold up a big jib. The fractional is more like a willow tree which bends to the wind to keep from breaking. Maybe mow later.
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
That was supposed to be "Maybe more later." as I was headed out.
For conversion of mast head to fractional you may need to add running backs to support the middle mast depending on where on the mast the jib head is placed. If you have aft lowers maybe not.
The Masthead rigs also have smaller mainsails typically which would mean you could end up with an underpowered rig. Not the worst thing if you sail in areas of bigger winds.
The fractional mast is typically more bendable making depowering the rig simple. You can just add backstay to bend the mast and flatten the large main. That won't work with the masthead mast. And, the fractional rig mast will bend to leeward as the wind pipes up causing twist in the main and depowering it. That feature won't work with the masthead mast.
A big advantage of the Fractional rig is the ease of tacking the smaller jib. You could accomplish that by using a 110 masthead jib without the labor and expense of adding hardware for the conversion.
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
I see this on my dock. The C30s have massive masthead rigged masts as opposed to my lighter, taller fractional mast
 
May 17, 2004
5,031
Beneteau Oceanis 37 Havre de Grace
I think by “fraculate” you don’t mean to make the rig fractional, but rather the technique of raking the mast forward, especially on a downwind run, to help with trim, correct?

If so, That sounds like a dangerous proposition on a mast head rig or any rig that’s not designed for it. You need to either move the keel step back or somehow bring the point where it leaves the deck forward. As you say, removing the mast wedges can do that, but then the mast will be unprotected against the deck, and will probably kink or dent there unless you soften the edge somehow. Also you’ll need to figure out how to prevent the mast from inverting with all of the rigging geometry changed. Boats like the Star class are built for this with adjustable mast steps and the deck rigging necessary to accommodate it, but on boats that aren’t I could imagine it going very badly.
 
Nov 26, 2012
1,653
Hunter 34 Berkeley
I'm not sure what you mean. If you want to bend the mast to flatten the middle of the main a baby stay serves that purpose but it is much harder to use on the fly. If you mean that you want to convert a masthead rig to fractional by moving the headstay attachment lower on the mast that is probably not a good idea. The sails and the keel work together in a beautiful ballet. To change the sail plan is to change the center of force which means that the balance between the sails and the keel will be compromised. Also, the rigging is set up to support the mast as designed. Changing that could mean added stress to the rig.
 
Dec 7, 2018
186
C&C 27 Mk V Vancouver
I think by “fraculate” you don’t mean to make the rig fractional, but rather the technique of raking the mast forward, especially on a downwind run, to help with trim, correct?
Yeah. I want to set up the backstay bridle so that when released all the way the pressure in the chute pulls mast up to at least TDC and possibly 2"-3" past. So not a lot.
From a raked position 7"-8" aft with no bend yet induced.
Straight spreaders, no babystay.
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
Sorry about my posts when I was ignorant of the term fraculate.
 
May 17, 2004
5,031
Beneteau Oceanis 37 Havre de Grace
Yeah. I want to set up the backstay bridle so that when released all the way the pressure in the chute pulls mast up to at least TDC and possibly 2"-3" past. So not a lot.
From a raked position 7"-8" aft with no bend yet induced.
Straight spreaders, no babystay.
So unless you alter the mast step geometry that will mean having negative 7” of bend. I don’t know too much about how well a mast will hold that amount of negative bend, but I’m scared. If you can alter the step to deck geometry then bringing the mast to pure vertical sounds feasible.
 
May 17, 2004
5,031
Beneteau Oceanis 37 Havre de Grace
Tilt, not bend.
So what you want is to be able to change the geometry of the mast step and deck pass-through so the mast can be straight at both 7” of rake and 0”. Let’s say you have a 40’ mast, and a 6’ distance from step to deck. At 7” of rake you need to have the deck pass through 1.05” behind the step. To bring the mast vertical you’ll need to either bend it forward, close that 1.05” gap at the deck, or slide the mast step back 1.05”. Unless the mast step is built for sliding it’s not going to move when loaded by the rigging. The last keel stepped boat I had had wedges at the deck, but they were probably only about 1/2”, not the 1.05” you’ll need. I guess it might be possible to replace all the wedges with some more adjustable setup, but you’ll need to be sure you can hold the mast steady there without kinking it.
 
Sep 25, 2008
957
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
You could make a beefy mast tabernacle that has a pivot bolt through the mast, keeping the mast raised above the deck. You could even taper the for and aft sides of the mast to gain more clearance. Of course, the whole set-up would have to be engineered to handle the forces.
 
Sep 25, 2008
957
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
How about a ball and socket setup , with the thru bolt.
 
Dec 7, 2018
186
C&C 27 Mk V Vancouver
If I still worked at the bicycle factory I might be able to induce the machinist w/lots of beer to fab a bar 'n groove system...lol maybe something with dozens of captive Torlon balls!