Multi-masted sailing cats

[mdcf]

Originally Posted by sigurd

Somewhere on the net, there was a multihull model with four or five masts standing on a horizontal boom, which rotated on a bearing at midship. Stagger was adjusted by rotating the boom contra the individual sheets. Can't remember for sure how but I think the whole boom was balanced by a tail.
Hope somebody can find that link.

I imagine that would work well if you could control the interaction between the sails and not end up loosing too much efficiency. It doesn't sound that practical when scaled up but you never know. The idea of using a tail with a trim tab sounds nice but how to make it look nice. I know should not be a driving force but the is something asthetically nice about current rigs especially if one does not want to end up spending a huge amount of time justifying a design. I also worry that the complexity starts to outweigh the benefit and relyability real quickly.

[mdcf]

From a thread over at SA, stubled on this Flickr page

http://www.flickr.com/photos/*******seaclub/3245564861/

Nice looking bi-rig 'Happy Feet'

[BigCat]

Originally Posted by mdcf

From a thread over at SA, stubled on this Flickr page

http://www.flickr.com/photos/*******seaclub/3245564861/

Nice looking bi-rig 'Happy Feet'

The flickr link doesn't work but here's a video:

http://www.youtube.com/watch?v=ZggxS...eature=related

Happy Feet not only is a pioneer with the biplane aka tandem righ, but it also has a unique hydrofoil system on a pod. Instead of trying to lift the whole boat, just the windward float is out of the water when the foils lift the boat. Looks a lot more controllable that the usual, in which the whole boat is lifted out of the water.

[oldsailor7]

I have enjoyed reading all the arguments and theories for multi masted multihulls, but I can only quote from real life experience.

In our multihull racing fleet we have a largish Catamaran with very efficient hulls. It has a schooner rig with two same height masts, and two same area fully battened mainsails. No Jibs or spinnakers.

It is fast on a reach. average to windward, slow downwind and SLOoooow to tack.

Give me a sloop rig any day. I'll tell you why in a later post. (Breakfast calling).

[oldsailor7]

In 1981 three of us sailed from Sydney to Lord Howe island in a sloop rigged Spindrift 45 catamaran.

It had been built by the skipper as a very comfortable and easily handled Cruising boat.
We left Sydney heads under main and Genoa and auto pilot. Light fitful winds limited our average speed to 6kts for the first 18hrs.

Then the wind started to rise. The Genoa was furled from the cockpit, and anticipating a south easterly buster, the skipper went forward and lashed the clew of the furled sail for safety's sake. THAT WAS THE LAST TIME ANYONE WENT ON DECK FOR THE REST OF THE VOYAGE..

The intent was to hoist a smaller jib, but the wind came up so quickly that that idea was shelved and we continued on under mainsail alone.
The seas became very big and the wind hit 50 kts gusting 55.
A reef was taken in the mainsail from the cockpit to reduce speed to around 11-12 kts for comfort sake.
When the speed rose to 17-18 kts another reef was taken in.
If we had been racing, the higher speeds would have been exciting---but we were cruising wern't we?
We homed in on Lord Howes beacon, sailing on a close reach, still on auto pilot.
We arrived warm and dry, having averaged 10.2 kts for the whole trip, beating the then racing record by a large margin.

Handling the sloop rig was a breeze with suitable winches (not powered), and all sail controls from the covered cockpit.

There is nothing wrong with a well laid out Sloop Rig.

[bill broome]

one mast is most efficient aerodynamically, but there is a case for a cutter rig on a cruiser.

[oldsailor7]

Originally Posted by bill broome

one mast is most efficient aerodynamically, but there is a case for a cutter rig on a cruiser.

Bill.
Note the second line of my post #80.

We could have hoisted a stormsail on our inner forestay, however it would have been an unpleasant and dangerous thing to do in those conditions.
The boat balanced perfectly on the double reefed main, whilst on auto pilot in 50kt winds and 40 foot seas.

As I said we were cruising, not racing. The effortless high average speed was just one of the bonuses of a big cruising Catamaran sloop.

The KISS principle in action.

[redreuben]

So Oldsailer do you think running backs are prudent or just 2 swept back shrouds?

[oldsailor7]

Originally Posted by redreuben

So Oldsailer do you think running backs are prudent or just 2 swept back shrouds?

00

Two swept back shrouds are OK for cruising, but runners are essential for racing.
Just my own opinion you understand.

[brian eiland]

Originally Posted by oldsailor7

The only reason I can think of as an advantage on that Trimaran is the fact that the mizzen sail enables the boat to balance, given the very forward position of the mainmast.

There are other justifications for a multimasted multihull other than just the rig configurations themselves. Have a look at what Chris mentions in posting #31

Originally Posted by Chris Ostlind

I've done a boat with a twin masted setup... a trimaran, and she is a really sweet machine for handling, as well as a good turn of speed. As mentioned, there are all sorts of reefing and boat balance options available to rig design of this type.

I liked it right away because it let me lower the COE quite a bit compared to a single, taller rig. This, in turn, gave me loads of options to design a set of very lightweight amas and lighter weight aka tubes. The masts, themselves, could then become self supporting, rather than further complicate the design with shrouds, stays and all the hard points to support same. It also removes the compression problems to a large degree, allowing for a lighter hull structure.

[ancient kayaker]

Originally Posted by mdcf

That sounds interesting, I assume you are using fixed wings? do you have any thought on how to reef the rig? Are you going to the triplane to keep the center of pressure low?

I'm particularly interested in the notion of balanced rigs, the loads that typically run through the running rigging seem unnecessary and a point of failure that could easily be avoided.

It's nice to know this interesting thread is still alive. I never answered your questions, mdcf. I did not get to test the triplane wingsail on a stick concept this year due to health problems now gone. I had to prioritize and a small sailboat got the nod. However, I did not forget about it.

Yes, I see the triplane concept as a way to keep the CoE low. It is difficult to reef a wing, especially if it is a hard one, so one method would be to remove one or two wings, which is something I would like to try, hopefully next year.

Originally Posted by sigurd

Somewhere on the net, there was a multihull model with four or five masts standing on a horizontal boom, which rotated on a bearing at midship. Stagger was adjusted by rotating the boom contra the individual sheets. Can't remember for sure how but I think the whole boom was balanced by a tail.
Hope somebody can find that link.

I know of some sites dealing with a wingsail that uses a "tailplane" to control the incidence but I haven't found one for multiwing configuration yet. Did you have any luck searching?

Originally Posted by Fanie

Oh I forgot to mention Marshmat, it may well be possible to sail directly to wind, if I get the rig I want together I may well be able to do so ...

Well? Is it? I'm going to start a new thread with an idea for doing just that.

[Chris Ostlind]

Originally Posted by brian eiland

There are other justifications for a multimasted multihull other than just the rig configurations themselves. Have a look at what Chris mentions in posting #31

After two years of sailing in a wide latitude of conditions, the twin rigged, XCR design has proven to be very effective in reaching its design goals. The owner, Kellan Hatch, has had it out in strong gusting conditions up in the mid 20's on two occasions and he simply reefed both sails and continued on with his journey.

The boat rigs in minutes and gives him a large potential when he wants to trim it for his on the water needs. Kellan has not set it up like this, yet, but the XCR can also be configured with a single rig that steps at a fairly typical location in the hull... without moving his leeboard for proper balance.

I'm really happy with this boat and the versatility it offers for coastal adventure cruising.

[elliott]

Originally Posted by sigurd

Somewhere on the net, there was a multihull model with four or five masts standing on a horizontal boom, which rotated on a bearing at midship. Stagger was adjusted by rotating the boom contra the individual sheets. Can't remember for sure how but I think the whole boom was balanced by a tail.
Hope somebody can find that link.

there was an actual boat called clifton flasher with this configuration designed by a bloke called nigel irens. here is an extract from a bio of irens published in the times. “We cleared out the pub with everyone deciding to design a boat for the Weymouth Speed Trials,” he said. “There was lots of arguing over design so we had competitions for one-metre long models on the pond at Portishead on Sunday mornings at 10 o’clock. People used to party until 2 o’clock in the morning and then build a model until 10 o’clock.

“We had ten people in the syndicate paying £50 each and unofficial sponsorship from the BBC — because most of the materials came from a friend who was a set designer there. We ended up with a boat with five solid sails, arranged like a Venetian blind. The Clifton Flasher, we called it. We held the record for a couple of years.”

i believe that this layout will be used one day with good effect. i see more than 5 blades, possibly with the rig being wider than the boat. reefing needs a bit of thought but since each blade would be relatively small, handling them might not be so tricky. plenty of low down grunt.

i witnessed clifton flasher sailing at weymouth and it looked good. very good. ahead of its time.

[brian eiland]

Clifton Flasher...and a few others

http://books.google.com/books?id=tE0...age&q=&f=false

http://content.yudu.com/A14dxe/Multi...sources/39.htm

[ancient kayaker]

The AYRS index credits Chris Robilliard with the design; presumably that's the production designer I find using Google. Apparently it took part in the John Player world speed sailing record attempt in Portland harbour but I can’t find the date. It is pretty much what I mentioned in post #73 but it doesn’t use the “tailplane” stabilizer,. There’s a pic of that concept here http://www.harborwingtech.com/