Sailboats with Free Standing Masts

[Snowpetrel]

Originally Posted by lounge sailor

Ok, I'll play.
We've lived on Copernicus, a Spencer 42 for 28 years. 18 years ago for a laugh and something to do we built a custom pre-peg carbon fibre free standing mast. It was designed by Eric Sponberg and he also designed a nifty carbon fibre spade rudder for the boat but thats another story.

Having the opportunity to sail the same boat with two different kind of rigs over a longish period of time has given us some cool insights to the good and bad of both.

Pluses and minuses of the unstayed compared to the old stayed rig on Copernicus

Pluses,
Faster, way faster, on all points of sail, especially in light airs.
Easier to handle despite having more sail area.
Sailing with just the main up is still pretty fast.
Quiet, no high pitched screeching in high winds.
On offshore passages reefing downwind is easier for crew to single hand.
Fewer single point failure scenarios.
Deeper DW angles without giving away too much boat speed.
Handier and more predictable in tight quarters.
A slight improvement in windward ability.
Having to unlearn a lot of ingrained stayed rig sailing knowledge/thinking.
Tons more fun to day sail.
Carey can and does sail the boat by herself with little effort.
Serious geeking out on Dyneema splices and the like. Of course the same can be done with a stayed rig so call that a wash.
Did I mention quiet?

Minuses
Getting proper, well shaped set of sails took work
Halyards that in our case need to be low stretch line.
One off rig means most of the hardware is custom (read expensive)
Having to beef up the gooseneck, deck gear, vang, mainsheet blocks and such.
Lightning now scares the crap out of me.
Having to unlearn a lot of ingrained stayed rig sailing knowledge/thinking.

Thats about it, me thinks,
Cheers,
Bryan
PS. In the bow on shot I'm sailing singlehanded in La Paz harbour in 20 knots of wind and in my excitment had forgotten to crank up on the jib halyard, hence the uncharactaristic jibstay sag. Thats my story and I'm sticking to it.
More photos and vids here. The Boat - oliveoyl

Thanks for the pics and the info, I was very impressed by the rightup by Eric Sponburg on the modifications you made to her, Glad to hear it has worked out longterm. I do have a few questions...

How do you get those reasonable forestay tensons? Running backstays or is the mast sized to work ok on its own with a little bit of help from the mainsheet and leech tension?

In stronger winds how does the jib go? I assumed it was more for light airs but these photo's show it being used in stronger winds.

What about a spinaker or Asymetric?

Cheers

[daletournier]

Originally Posted by lounge sailor

Ok, I'll play.
We've lived on Copernicus, a Spencer 42 for 28 years. 18 years ago for a laugh and something to do we built a custom pre-peg carbon fibre free standing mast. It was designed by Eric Sponberg and he also designed a nifty carbon fibre spade rudder for the boat but thats another story.

Having the opportunity to sail the same boat with two different kind of rigs over a longish period of time has given us some cool insights to the good and bad of both.

Pluses and minuses of the unstayed compared to the old stayed rig on Copernicus

Pluses,
Faster, way faster, on all points of sail, especially in light airs.
Easier to handle despite having more sail area.
Sailing with just the main up is still pretty fast.
Quiet, no high pitched screeching in high winds.
On offshore passages reefing downwind is easier for crew to single hand.
Fewer single point failure scenarios.
Deeper DW angles without giving away too much boat speed.
Handier and more predictable in tight quarters.
A slight improvement in windward ability.
Having to unlearn a lot of ingrained stayed rig sailing knowledge/thinking.
Tons more fun to day sail.
Carey can and does sail the boat by herself with little effort.
Serious geeking out on Dyneema splices and the like. Of course the same can be done with a stayed rig so call that a wash.
Did I mention quiet?

Minuses
Getting proper, well shaped set of sails took work
Halyards that in our case need to be low stretch line.
One off rig means most of the hardware is custom (read expensive)
Having to beef up the gooseneck, deck gear, vang, mainsheet blocks and such.
Lightning now scares the crap out of me.
Having to unlearn a lot of ingrained stayed rig sailing knowledge/thinking.

Thats about it, me thinks,
Cheers,
Bryan
PS. In the bow on shot I'm sailing singlehanded in La Paz harbour in 20 knots of wind and in my excitment had forgotten to crank up on the jib halyard, hence the uncharactaristic jibstay sag. Thats my story and I'm sticking to it.
More photos and vids here. The Boat - oliveoyl

Hi Brian, I remember reading about your boat when I was into the freestanding mast thing, or should say when I owned one.

Did you have to strengthen the deck where the mast went through?

It looks great. I like the roachy main. Although I have a rig held up by wires now I still believe freestanding is the way to go.

And yes lightening always freaked me out to.

[lounge sailor]

Originally Posted by Snowpetrel

Thanks for the pics and the info, I was very impressed by the rightup by Eric Sponburg on the modifications you made to her, Glad to hear it has worked out longterm. I do have a few questions...

How do you get those reasonable forestay tensons? Running backstays or is the mast sized to work ok on its own with a little bit of help from the mainsheet and leech tension?

In stronger winds how does the jib go? I assumed it was more for light airs but these photo's show it being used in stronger winds.

What about a spinaker or Asymetric?

Cheers

Thanks Snowpetrel
Regarding forestay tension.
The mast is stiffer fore and aft due to the elliptical section which is different than a typical round section Freedom mast. The modified entasis geometry which is like the top half of a greek column does the rest.
I've included a drawing showing the differences between the entasis mast Eric designed and a typical Freedom single taper mast. The entasis mast is red. It is parallel sided for the first 20 feet from the mast base. As you can see its a series of increasing angles as you go up which results in a larger middle section area (and hence stiffer) compared to the freedom mast. The mast base is actually smaller in diameter than an equivalent freedom mast.
The results are that the geometry doesn't get in the way of forestay tension like a freedom mast might or put another way it helps forestay tension.

As you can see in the bow on sailing photo I posted earlier the mast is not bending like a single taper fishing pole would. When I tighten the jib halyard I crank on the halyard winch till I can't crank anymore. It must be in the thousands of pounds of load.
I can't really see any forward bend in the mast so the mast must be very stiff fore and aft.
You are right that the endboom mainsheet and leech tension contributes to forestay tension and in fact Eric insisted we up the load numbers on the mainsheet system to allow it to be a part time backstay.
For fun I'm including a drawing of the fractional jib arrangement. Takes a lot of point loading off the mast and I think puts it in compression.
I did want running backs but Eric shrugged his shoulders and said if I wanted to, to go ahead but leave off the runners till I sailed the boat for a bit. He figured we wouldn't need em and he was right.


If we are daysailing or day hopping up a coast we will push the boat so we'll use the jib a lot but passage making we tend to keep an eye on things and at the slightest bit of weather we'll furl it (its on a Collego furler) and then unfurl the staysail which is usually up and furled ready to go when on passage.

Since the boat hits hull speed downwind in much lighter winds with what we already have in sails my dreams of an asymmetrical spinnaker have faded a bit. Eric has stated the mast can handle those kinds of loads. If I had a spinnaker block at the mast head and was able to fly a spinnaker I don't think the mast would notice.
The cool bit would be dumping the furled jib and staysail down on deck and having an open sans forestay triangle for screwing up spinnaker sets in an elegant way

Anyway it's a great rig and boat to geek out on and even 18 years later we're still learning something new about them.
Cheers,
Bryan

[lounge sailor]

Originally Posted by daletournier

Hi Brian, I remember reading about your boat when I was into the freestanding mast thing, or should say when I owned one.

Did you have to strengthen the deck where the mast went through?

It looks great. I like the roachy main. Although I have a rig held up by wires now I still believe freestanding is the way to go.

And yes lightening always freaked me out to.

Hi Daletournier

Thanks and yes we did a lot of strengthening to the deck (and mast step) to keep the contraption up right.
Sailing that big roach with a bendy rig was one of the un learning things we had to do to get the bucket up to speed, it's lots of fun.
I don't think I'll ever get over my fear of lightning. When next we do a refit, repaint on the mast I'm going to lam up an outside layer of that aluminium or copper weave they are now putting on carbon fibre planes. That might help the pucker factor a bit.
Cheers,
Bryan

[Steadman Uhlich]

Nice photo of a 1980 Freedom 35 Cat Ketch under sail.

[Snowpetrel]

Originally Posted by lounge sailor

Thanks Snowpetrel
Regarding forestay tension.
The mast is stiffer fore and aft due to the elliptical section which is different than a typical round section Freedom mast. The modified entasis geometry which is like the top half of a greek column does the rest.
I've included a drawing showing the differences between the entasis mast Eric designed and a typical Freedom single taper mast. The entasis mast is red. It is parallel sided for the first 20 feet from the mast base. As you can see its a series of increasing angles as you go up which results in a larger middle section area (and hence stiffer) compared to the freedom mast. The mast base is actually smaller in diameter than an equivalent freedom mast.
The results are that the geometry doesn't get in the way of forestay tension like a freedom mast might or put another way it helps forestay tension.

As you can see in the bow on sailing photo I posted earlier the mast is not bending like a single taper fishing pole would. When I tighten the jib halyard I crank on the halyard winch till I can't crank anymore. It must be in the thousands of pounds of load.
I can't really see any forward bend in the mast so the mast must be very stiff fore and aft.
You are right that the endboom mainsheet and leech tension contributes to forestay tension and in fact Eric insisted we up the load numbers on the mainsheet system to allow it to be a part time backstay.
For fun I'm including a drawing of the fractional jib arrangement. Takes a lot of point loading off the mast and I think puts it in compression.
I did want running backs but Eric shrugged his shoulders and said if I wanted to, to go ahead but leave off the runners till I sailed the boat for a bit. He figured we wouldn't need em and he was right.


If we are daysailing or day hopping up a coast we will push the boat so we'll use the jib a lot but passage making we tend to keep an eye on things and at the slightest bit of weather we'll furl it (its on a Collego furler) and then unfurl the staysail which is usually up and furled ready to go when on passage.

Since the boat hits hull speed downwind in much lighter winds with what we already have in sails my dreams of an asymmetrical spinnaker have faded a bit. Eric has stated the mast can handle those kinds of loads. If I had a spinnaker block at the mast head and was able to fly a spinnaker I don't think the mast would notice.
The cool bit would be dumping the furled jib and staysail down on deck and having an open sans forestay triangle for screwing up spinnaker sets in an elegant way

Anyway it's a great rig and boat to geek out on and even 18 years later we're still learning something new about them.
Cheers,
Bryan

Thanks for your detailed description that satisfies the engineering nerd in me. A very clever bit of design work by Eric Sponburg. I guess getting the luff curve of the jib just right is also pretty critical to allow for a bit more sag.

The detail of the halyard is interesting. I guess it reduces the need for halyard slot at a highly stressed part of the mast? Is it a two to one halyard or direct, and what size rope and winch are you needing to get resonable stay tension? Any chafe issues on this highly loaded rope?

How well does she sail with no headsail? And what is the staysail setup and wind range. I guess in a real blow you can just deep reef the main and sail baldheaded, or if downwind set the staysail and drop the main and use the topping lift or halyard as a backstay?

Anyway it pretty neat to see an effevtive setup for an unstayed rig with decent headsails. The ones on the freedoms always looked very saggy. I also suppose the greater fore and aft stiffness helps prevent whip when punching into a chop under motor.

[Steadman Uhlich]

The Freedom 40 Cat Ketch is one of my favorite boats.

I just posted more info (a current boat for sale) and more photos at this thread:
http://www.cruisersforum.com/forums/...ml#post2591028

Here are a few photos I liked, share here for other FSM fans to see.

[lounge sailor]

Originally Posted by Snowpetrel

Thanks for your detailed description that satisfies the engineering nerd in me. A very clever bit of design work by Eric Sponburg. I guess getting the luff curve of the jib just right is also pretty critical to allow for a bit more sag.

The detail of the halyard is interesting. I guess it reduces the need for halyard slot at a highly stressed part of the mast? Is it a two to one halyard or direct, and what size rope and winch are you needing to get resonable stay tension? Any chafe issues on this highly loaded rope?

How well does she sail with no headsail? And what is the staysail setup and wind range. I guess in a real blow you can just deep reef the main and sail baldheaded, or if downwind set the staysail and drop the main and use the topping lift or halyard as a backstay?

Anyway it pretty neat to see an effevtive setup for an unstayed rig with decent headsails. The ones on the freedoms always looked very saggy. I also suppose the greater fore and aft stiffness helps prevent whip when punching into a chop under motor.

Hi Snow Petrel,
Yes, you're right, the luff curve design on the jib is critical on this rig and sailmakers usually got it right so theres that. They seem to have a tough time with the mainsail shape but with getting the finite element analysis into the hands of the sailmaker we got a beautifully shaped main this time around.
Eric's engineering was brilliant and not only did he design a complex workable geometry but his lam schedule is elegant as well. I even suspect that he wiggled an entasis into that lam so it's not just a single taper from the mast butt to the mast head. The mast step lam thickness is a bit over a 1/2” and the mast tip is a little over 1/8”. It was a pleasure to work from his lam schedule tables.

The mast is completely airtight so any halyards have to be external. I actually got the idea for the jib halyard arrangements from another of Eric's clients who had a free standing wing mast cat ketch open 60 built. He had a string of jib tangs all up and down the front of the masts of that boat and they all had that set up. The boats name was Project Amazon, amazing sailing machine.
Our jib halyard is one part to a winch and we vary on the low stretch halyards from 7/16 to 9/16 and so far no chafe issues which I'm happy about.

Eric originally specified fairleads going up the mast on the outside for the halyards. His reasoning being that the highly loaded lines needed to be as close to the mast as possible to avoid the “bow” effect. Well I dutifully installed those and in two years the halyards had worn through them with no change at all. Told Eric and he said oh, very well, carry on.
The staysail range is good up to 60 knots so far, got caught in a big system in the Gulf of Florida coming up from Panama last spring so that I know for sure. The boat heaves too nicely as well.
Regarding sailing bald headed. When we installed the mast we had to move it about 1 1/2 feet forward of the original to accommodate structural bulkheads and the like. I suspect that fact contributes to the amazing abilities of the boat without headsails. I've never missed a tack in light or heavy airs. She just snaps through without a hitch. If we are running DW. in biggish seas and a brisk winds of say 25 knots we would have 2 or if we are tired 3 reefs in the main with no headsails at all. The Hydrovane just works merrily away and so far we haven't come close to an accidental gybe. Never say never though
Short tacking up narrow channels in anything over 10 knots we usually do with just the main up, its a delightful way of seeing the scenery without having to put your coffee down to tack.
Copernicus is a tiller steered boat so we'd know immediately if the balance was off. I wouldn't call it a dainty fingertip feel but it is nice to steer with main only and the weather helm is around 2 to 5 degrees tops.
You are absolutely correct about the engineering that went into the boat. Messing around with all that stuff is almost as much fun as sailing the results.
By the way love the blog and that dinghy design is gorgeous. I'm a big fan of rowing dinghies.
Cheers,
Bryan

[daletournier]

Hi Bryan, I know it was sometime ago put what was the cost of the conversion, if your happy to share.

This thread really stirs me up regarding fsm, I was a big fan. When it come to buying my current boat (which I like) I resigned myself to buying wires as the choices of fsm used boats is so limited and the likes of Wylies are to pricey for me. Such a pity they haven't been more accepted.

I also very much like the aerorigs on cats, ugly but make alot of sense to me.

[lounge sailor]

Originally Posted by daletournier

Hi Bryan, I know it was sometime ago put what was the cost of the conversion, if your happy to share.

This thread really stirs me up regarding fsm, I was a big fan. When it come to buying my current boat (which I like) I resigned myself to buying wires as the choices of fsm used boats is so limited and the likes of Wylies are to pricey for me. Such a pity they haven't been more accepted.

I also very much like the aerorigs on cats, ugly but make alot of sense to me.

Hi daletournier

I always feel compelled to talk folks off the ledge when they start talking about converting a rig. Sort of a mission in life if you like
But to answer your question,
Everything on the old rig was twenty years old and needed replacing or refitting, mast, rigging, sails and hardware. Just a refit on that rig would have cost plenty. I knew that amount was going to be spent regardless. So using man math I thought we'd subtract that figure from what a free standing rig would cost and Voila! Instant acceptable numbers

In spit of the kidding around it was expensive. With our labour we managed a sail away cost of 5000.00 less than what a CT37 cutter cost that happened to be professionally outfitting in Vancouver at the same time. That cutter had to be new rigged from the deck up, mast, boom, bowsprit, deck hardware, standing and running rigging and 3 sails. I'm not sure about the real costs of rigging the cutter I only know this because a broker who asked about my finished costs and was close to the cutter project told me. That was 18 years ago so memory may be failing.

So, mast built, painted and fitted out, 3 new spectra sails, running rigging and all new deck gear, winches, mainsheet system and the like not to mention the fairly major structural changes to the deck and cabin came to around 45,000 to 50,000
As I recall the mast itself, bare tube along with everything it took to build, hot out of the oven came to 20,000
If we were only interested in just getting a new rig and nothing else we might not have actually proceeded but we were so curious about the engineering and the process and were excited about the prospect of working with materials such as pre-peg carbon and all its attendant tech. That was the tipping point. It was an orgy of geeky engineering.
We knew we would never recoup our investment in financial terms but we have recovered the cost many times over in the interest, curiosity and sheer pleasure of sailing this rig.

Areorigs never caught on for the most part because they were breathtakingly heavy not to mention complicated and expensive. I've meet folks who removed them after a while.

Hope this has talked you off the ledge

Cheers,
Bryan

[lounge sailor]

To get back on track here is my latest favourite freestanding mast sailboat. The Ikon 7.5
The French are doing some very innovative things with free standing rigs.
Cheers,
Bryan

Construction voilier pêche promenade

[Steadman Uhlich]

TO LOUNGE SAILOR (Bryan)

Thanks for taking the time to describe your FSM rig, Including the costs and satisfaction, and the pro and cons. Very interesting and helpful posts on this FSM thread.

[daletournier]

Originally Posted by lounge sailor

Hi daletournier

I always feel compelled to talk folks off the ledge when they start talking about converting a rig. Sort of a mission in life if you like
But to answer your question,
Everything on the old rig was twenty years old and needed replacing or refitting, mast, rigging, sails and hardware. Just a refit on that rig would have cost plenty. I knew that amount was going to be spent regardless. So using man math I thought we'd subtract that figure from what a free standing rig would cost and Voila! Instant acceptable numbers

In spit of the kidding around it was expensive. With our labour we managed a sail away cost of 5000.00 less than what a CT37 cutter cost that happened to be professionally outfitting in Vancouver at the same time. That cutter had to be new rigged from the deck up, mast, boom, bowsprit, deck hardware, standing and running rigging and 3 sails. I'm not sure about the real costs of rigging the cutter I only know this because a broker who asked about my finished costs and was close to the cutter project told me. That was 18 years ago so memory may be failing.

So, mast built, painted and fitted out, 3 new spectra sails, running rigging and all new deck gear, winches, mainsheet system and the like not to mention the fairly major structural changes to the deck and cabin came to around 45,000 to 50,000
As I recall the mast itself, bare tube along with everything it took to build, hot out of the oven came to 20,000
If we were only interested in just getting a new rig and nothing else we might not have actually proceeded but we were so curious about the engineering and the process and were excited about the prospect of working with materials such as pre-peg carbon and all its attendant tech. That was the tipping point. It was an orgy of geeky engineering.
We knew we would never recoup our investment in financial terms but we have recovered the cost many times over in the interest, curiosity and sheer pleasure of sailing this rig.

Areorigs never caught on for the most part because they were breathtakingly heavy not to mention complicated and expensive. I've meet folks who removed them after a while.

Hope this has talked you off the ledge

Cheers,
Bryan

Hey Brian, lol.. not on the ledge, not something I'll be doing, just curious. Sounds like it was a real cool project.

Thanks.

[lounge sailor]

Originally Posted by Steadman Uhlich

TO LOUNGE SAILOR (Bryan)

Thanks for taking the time to describe your FSM rig, Including the costs and satisfaction, and the pro and cons. Very interesting and helpful posts on this FSM thread.

Thanks Steadman, glad to contribute plus its all fun.
Cheers,
Bryan

[lounge sailor]

One more,
A few French designers like Gilles Montaubin are also fooling around with modern versions of the old Ljungström rigs which are free standing masts that rotate in order to furl the mainsail around the mast.
Some French builders are also experimenting with vertical battens to achieve greater roach in Ljungström rigs. Simple, easy to repair, low tech, whats not to like.
Cheers,
Bryan
etroit-mousquetaire-790 - etablimarin-chantiernaval