Sailboats with Free Standing Masts

[gamayun]

Originally Posted by Steady Hand

Mike,

Welcome aboard CF and to this discussion too!

Your boat looks very nice!

I will admit I am no expert on the Aerorig, and one other boat I had seen with the rig turned me off, mostly because of unfamiliarity (guilty) and because on the look of that boat on which the scale of the rig seemed off to my eyes. It looked big and bulky.

Your boat does not give me the same negative impression, and instead looks very nice, nicely propotprtioned.

I hope you will tell us all something of your views as an owner, based on your extensive experience with many miles using it.

Yes, do tell, Mike! I've never seen anything like this. It's very cool. Does the whole boom thing rotate? How do you ease the sheets? Do you fly a spinnaker? So many questions...Oh, and welcome!!

[MichaelMaunsell]

Hi Steady

Thanks for the welcome.

You may be surprised to hear that I agree with you on aesthetics! La Novia is a beautiful boat and she turned heads wherever she went, but the truth is that the fore boom detracted from her looks rather than enhancing them. She could live with that because her curved wing section mast drew the eye away from the foreboom. The best looking aerorig I've seen was on a huge dutch yacht where the booms were a tubular lattice space frame instead of a solid grp structure.

I really liked the rig & I'd have no hesitation in going offshore with one again. Easiest to summarize as Pro's & Con's. Start with the bad news.

DRAWBACKS

No spinnaker so a dead run downwind in light airs is frustrating. You really want 14 kts true wind if its right behind you.
Big front end windage. The mast is stepped forward of the keel and there is serious windage in both the mast and the fore boom. As a consequence, the boat is a right handful in the marina on a windy day and her behavior at anchor is appalling!
You can't heave to.
Sail handling can only be done at the mast and with a 1200 sqf mainsail you need to be in reasonable physical shape to cope with a problem in heavy weather.
Too little to hang on to at the top of the mast. Sounds trivial, but it's not. I had to go to the top of the mast in 35 knots with a 3 metre breaking sea & sustained the worst bruising of my life.
Main boom touches the water when the boat rolls running goose winged. Not the end of the world but an irritant if your hull rolls going downwind. We had a lifting keel which we would raise downwind & that pretty much solved the issue.
Aesthetics. The fore boom just doesn't look right.
Psychology . You have to get used to the mast flexing & the end of the boom moving up and down as the boat pitches. Just like monohull sailors find that creaking noise as a catamaran flexes a bit unsettling!


BENEFITS

Brilliant shorthanded rig. Everything is controlled on a single mainsheet on a small manual winch. Just effortless. Easy single handed sailing.
Brilliant short tacking out of a narrow channel with the wind on the nose. Words cannot describe how good she was at this.
Balanced rig. As long as you keep the rig balanced, you cannot crash jibe. When you jibe, the rig settles gently into place without any impact on the main sheet.
Low sheet loads. The rotational forces of the jib cancel out an equal force from the main, so the sheet loading is about 1/3 of that on a conventional rig. Big deal if you are cruising on a powerful boat with young children.
No standing rigging to fail. I was insured with a Dutch insurer that covered almost all the bigger aerorigs and my premiums were 20% less than for an equivalent stayed rig. They told me that they had never known an aerorig to be dismasted and that their experience was that the majority of dismastings were caused by failure of the standing rigging, not by the boat being rolled.
No standing rigging to maintain.
Uncluttered decks & useable foredeck.
Quick & easy to depower. Just ease the mainsheet till she spills & voila. No need to reef for trade wind squalls - just spill.
Virtually zero chafing. Only the lazy jacks to worry about.
Jib trim & therefore the slot is always perfect.
Beautifully balanced under bare poles. No storm sail needed.


Happy to answer specific queries in more depth.

Mike

[MichaelMaunsell]

Originally Posted by gamayun

Yes, do tell, Mike! I've never seen anything like this. It's very cool. Does the whole boom thing rotate? How do you ease the sheets? Do you fly a spinnaker? So many questions...Oh, and welcome!!

Hi Gamayun

It's simple.

The boom is a single rigid structure from the front to the back.

It is bolted to the mast.

The mast has a large bronze pin on its end, which is stepped in a delrin bearing on the bottom of the hull, just forward of the keel.

There is a second delrin bearing in the deck.

Obviously the engineering holding these bearings and distributing the loads from them has to be about right.

The mast rotates freely through 360 degrees in these bearings.

The jib is self tacking and runs on a track mounted on top of the foreboom just forward of the mast.

Once the jib is unfurled and sheeted in tight to the runner on the track, you stow the sheet and forget it.

The main boom is controlled on a single, double ended sheet running to a small winch on each side of the cockpit.

As long as there is more sail area behind the mast than in front, the rig will weathercock into wind. To set the rig for a particular point of sail, just sheet in the mainsheet until the sails are flying right.

To bear away: ease the mainsheet as you bear away. To come up: point up and sheet in. That's it - you're sailing!

La Novia goes like a Swan 60. The difference is that you don't need the 6 seriously grown up blokes on board to sail her!

Cheers

Mike

[beiland]

Fairly early on in the developments of the aerorig there was a catamaran version designed by John Shuttleworth
John Shuttleworth AeroRig 52

I was inspired by John's treatment of bulkhead support for that free standing mast when i drew up this Dynarig free standing mast idea.
Main BulkHead and Constructioin Specs


Here is another nice looking aerorig cat by Kurt Highes
Kurt Hughes Multihull Design - Catamarans and Trimarans for Cruising and Charter - 56' Catamaran w/Aero Rig

Originally Posted by MichaelMaunsell

The best looking aerorig I've seen was on a huge dutch yacht where the booms were a tubular lattice space frame instead of a solid grp structure.

Is this the big Dutch vessel you speak of?
Rotating AeroRig | Page 2 - Technical Discussion | YachtForums: We Know Big Boats!

[beiland]

Some more photos of that Dutch built 'super aerorig', and a few other discussions of the subject:

AeroRig - Page 2 - Boat Design Forums

[MichaelMaunsell]

Is this the big Dutch vessel you speak of?
Rotating AeroRig | Page 2 - Technical Discussion | YachtForums: We Know Big Boats![/QUOTE]

Yes. It was designed by Gerard Dijkstra.

[Steadman Uhlich]

Mike,
That is a very good outline of drawbacks and benefits you posted!

Thanks for taking the time to put your comments down.

I am sure that will help many sailors learn.

[MichaelMaunsell]

Originally Posted by beiland

I was inspired by John's treatment of bulkhead support for that free standing mast when i drew up this Dynarig free standing mast idea.
Main BulkHead and Constructioin Specs

That is a very elegant solution to handle the lateral loads.

How do you deal with the fore and aft loads in this design?

[beiland]

Originally Posted by MichaelMaunsell

That is a very elegant solution to handle the lateral loads.

How do you deal with the fore and aft loads in this design?

The athwartship loads are the biggest, as the ship support structure acts to resist movement and overturning in that direction.

The fore-to-aft forces on the contrary are encouraged to move the vessel forward, so the structure does not need to be as strong in that direction. But you will notice there is a fairly thick beam structure (X-shape) reinforcing the tube receptacle of the free standing mast (you can see some of that HERE)

There is also a lengthwise nacelle plate down the centerline of the vessel that imparts fore-to-aft rigidity to the vessel as well as under that mast stepping receptacle tube.


There is also the possibility of a permanent backstay,

and a forestay that might be utilized in heavy sea situations.
DynaRig Sail Plan

[pbr]

Here is a picture of a 52 ft. aluminum catamaran with carbon free standing mast and jib Camber Spar I built a few years back, routinely sailed single handed by it's owner

[beiland]

Who was the designer PBR?

[pbr]

Concept and project manager me, N.A. and designer Cort Steck

[Kiss2016]

I saw your invitation to post pictures of our boats so i thought It would be appropriate to post some pics of the cat ketch free standing masts that I bought in January in Malaysia. These are pics from the vendor files. The boat is now red with a white diagonal stripe. It is a custom version of a Freedom 40.

One advantage of a cat ketch free standing masts with wishbones and which is rarely mentionned is the price for which you can get one. Kiss (Keep It Simple Sailing) was built in Germany by skilled workers out of marine grade aluminium and has a very reliable Sabb engine. I was able to purchase that boat for 27 000$ US. Even in my wildest dream I could not envisionned myself with an aluminium boat that size.

It is my first boat. I have been sailing on boats too big for their owners to handle by themselves. I promised myself that I would not buy any bigger than a 33 ft but when I found her, I realise that I could go bigger and still sail it single handed while enjoying bigger water tankage (500 liters), bigger fuel tankage (550 liters) and a roomier interior and still benefit from a shallow draft 1.2 meter (3.9 ft) keel up.

27 000 $ US for a Freedom 40 aluminium copycat. Is it not another argument for going free standing cat ketch rig ?

[daletournier]

Hi , congratulations on your purchase, I hope you really enjoy her. Im flying back to my Freedom in Phuket next week. If I see you around I'll make a point of saying hello.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

[Kiss2016]

Hi,

I am currently in Yacht Haven Marina.

It would be nice to meet indeed.

Is your boat rigged with wishbones ?