50/50 or 100/100.

[FAST FRED]

"I can't see how low quality sandwich construction can compete. Also, it wouldn't be a Herreshoff. He strongly emphazised that he would never allow one of his boats to be built out of "frozen snot""

Hand layup of a proper engineered foam core is hardly "low quality sandwich construction " after all Franz Mass built a reputation on going racing in his plug built hand layup sail boats.

No if building with 4x6 timber in 12 inch centers and 1 1/2 inch planking is needed to be a "real" Herrishoff , a frozen snot variant would not be OK.

And gasoline Sterlings are hard to find parts for, these days.

But if the design concept , how to cross oceans with tiny crew , little fuss , and advance at 240 miles a day is used as a goal for a more modern boat , the IDEAS in the Marco Polo are of use.

A 55ft hull of 3/4 inch Airex and built to OCEAN standards will come in at 3 lbs per sq ft.
About the same as 1 inch mahog hull , sans ribs backbone ect .

This is with 3/4 oz matt and 24oz woven roving on the topsides , inside & out.
The extra internal layer of 3/4 mat adds little extra weight but creates a finished interior surface.

FAST FRED

[brian eiland]

Originally Posted by gonzo

The term motorsailor was a marketing ploy. The salespeople claim you could get the best of both world without any drawbacks.

Originally Posted by kjell

A Motorsailer is a displacement hull and limited to the hull speed

I don't agree that a motorsailer needs to be a displacement vessel. And I don't think the term was a marketing ploy.

I'm also not real enthused that we need to pin down some technical forumla to define a motorsailer....gets overly complicated. Rather I feel the term may have simply come about to define a vessel whose intentions it was to be utilized in both sailing and powering modes....unlike a sailing vessel that might employ an auxillary engine for docking or no wind....or a power vessel that makes no pretentions of utilizing sail power.

So the motorsailer is very definitely its own type of vessel. But as I've written before, we don't hear much of motorsailers these days. They're not a popular subject. Traditional motorsailers have always been such a compromise, they have fallen into disfavor in the market, and in the boating literature. The term has even had negative connotations for several decades now. (as Tad said, even some designers rejected the term).

On the contrary, I embrace the term. Should not today's boats be faster and better with new materials, light marine diesels, and better shapes? Should not this be the sensible alternative, the common sense move up from the beloved family sailboat? When trawler options are discussed, suggestions of boredom arise. A lifetime of sail would be discarded, and what happens when the motor quits? Well, hopefully it won't quit, but one can always sail home in a boat with sails on it. For truly long-range cruising and/or remote exploration, the motorsailer can outshine both the sailing aux and the trawler types.

We need to modernize the motorsailer. The multihull plan-form holds great promises to improve this breed. The long slender hulls of the catamaran type vessel have proven themselves to be real efficient to push under both power & sail. And not only are they efficient, but they can be pushed beyond the traditional hull-length/speed limitations. Just what the modern motorsailer needs, a far less compromising increase in both their sail & power performance, while maintaining an economy of operation that allows truly long range capability.

In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone……
.sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs.

more? http://boatdesign.net/forums/showpos...1&postcount=25

[FAST FRED]

The only problem being the fact that CATAMIRANS CAPSIZE ,
so their ability to ocean cruise is merly a roll of the dice , before the "big one" turns the boat turtle.

Recent NASA data claims the number of LARGE waves is very underestimated world wide , as the commercial boats travel only in limited sea lanes, and don't get to see the BIG ONES.
Cruisers usually avoid the "low power steam" routes and will be more exposed than the ESSO MARU.

Traveling "in season" will reduce the risks , but its only time before the righting gear will be needed.

A trimiran can have a better chance at offshore self recovery , but lacks the 4 bedroom apartments with ballroom some "need" to cruise with.

A self righting monohull would be the classic choice , but getting todays accomidation into a hull 6 or 8X as long as it is wide would be the chalenge.

I believe if cruisers can accept the accomidations of a 40 ft'er in a 65 or 70 ft SKINNY boat the 10K+ 10mpg+ M/S cruiser could be done.
AS the weight would be close to the 40ft M/S , the cost to construct would be similar.

Any designs for that?

FAST FRED

[yipster]

Originally Posted by FAST FRED

Any designs for that?

FAST FRED

http://www.morozov-yachts.com/index.php?catalog=156

think i still favor the bigger cat tho...
as you said "righting" may be an design challange
and when a mono rolls you may even get wetter
where did i read bout masttop cushions....

[Raggi_Thor]

Something like this? or ist it too fat?
http://www.sailmagazine.com/boatreviews/Convergence/
http://www.wyliecat.com/yachts/models/wyliecat_65.html
Seems like it does 11 knots with a 100HP Yanmar.

[brian eiland]

Originally Posted by FAST FRED

The only problem being the fact that CATAMIRANS CAPSIZE ,so their ability to ocean cruise is merly a roll of the dice , before the "big one" turns the boat turtle.

By that definition then no power boat should go to sea as they can rolled over rather easy, and don't self-right.

Originally Posted by FAST FRED

A trimiran can have a better chance at offshore self recovery

How do you arrive at that conclusion?

[yipster]

Originally Posted by Raggi_Thor

http://www.wyliecat.com/yachts/models/wyliecat_65.html
Seems like it does 11 knots with a 100HP Yanmar.

good articles Raggi but why is the wiliecat a mono

[Vega]

Originally Posted by brian eiland

I don't agree that a motorsailer needs to be a displacement vessel. And I don't think the term was a marketing ploy.

I'm also not real enthused that we need to pin down some technical forumla to define a motorsailer....gets overly complicated. Rather I feel the term may have simply come about to define a vessel whose intentions it was to be utilized in both sailing and powering modes....unlike a sailing vessel that might employ an auxillary engine for docking or no wind....or a power vessel that makes no pretentions of utilizing sail power.

Brian, I agree with you about this, but the distinction between sail boat and motor sailor that you have made is not clear enough, at least for me.

When you say that a sailboat is a “vessel that might employ an auxiliary engine for docking or no wind....” well, a Motor sailor as well. If you say that a sailboat has an engine that is used mostly for docking, then you are excluding the vast majority of boars that are sold as sailboats.
Nowadays a 36ft boat is sold with an engine of around 30hp and a 40ft with an engine of about 50hp. These engines on those boats can handle almost all situations, being able to travel exclusively using its engine in most situations.

That engine is not enough only in unusual situations, in gale force winds going windward, etc.
The differences regarding a motor sailor are that this one has the extra power to handle these situations, too. I would say that for doing that, in a 36 ft will be required an engine of at least 50 hp, and in a 40ft, an engine of 75 hp.

As to cats, I agree with you in what concerns coastal crafts, but regarding passage makers, I agree with Fred. A cat without any sail can be capsized only by the pressure of the wind on the mast. Sure, it is needed a lot of wind, but in a recent ocean race, several capsized that way. For those, that had a massive RM, 70knots is enough.
70 knots of wind is not very common but I bet that several members of this forum have already encountered that. I guess they would not make it in a Cat.

Even in the Med, there are some stories of crews of big cruising cats that have been in deep trouble with 9 and 10 force winds. Out of the summer months, in some zones, the wind can blow often like that.

Of course this can be overcome if you use smaller rigs, but then the sailing performance will suffer.

There are other options: one is to consider a rig not normally used in cats, a Gaff rig with a big bowsprit; another is to use a variant of a Latin rig (Catalans have a race with traditional boats that have to use Latin rigs. It’s incredible the performance and the upgrades they have introduced in that rig). These types of rigs without sails are a lot shorter, for the same sail area, therefore they will offer a smaller resistance to the wind.

[brian eiland]

Originally Posted by yipster

good articles Raggi but why is the wiliecat a mono

It's in reference to the 'cat rig' of their smaller and very popular vessel,
"The Wyliecat 30 was conceived with the premise that performance sailing doesn't need to be complicated to be fast and fun. Combining state-of-the-art technology with the time-proven cat rig...."
http://www.wyliecat.com/yachts/models/wyliecat_30.html

[Vega]

Originally Posted by yipster

good articles Raggi but why is the wiliecat a mono

Hello Yipster

Cat here doesn't come from Catamaran.

It comes from an American traditional type of boat, the Cat boat.

Those boats have only one sail, with the mast near the bow.

http://www.catboats.org/gallery.htm

[yipster]

thanks guy's, i'm only a (originaly advertising) designer studying boats

[brian eiland]

Originally Posted by Vega

... the distinction between sail boat and motor sailor that you have made is not clear enough, at least for me.When you say that a sailboat is a “vessel that might employ an auxiliary engine for docking or no wind....”

...and additionally powering for some significant portion of journeys. Yes there are various degrees of sailing verses power and 'sailing under power'. The intention of the design is to power more than the needs of an 'auxillary' craft.
_____________________________________________________

Originally Posted by Vega

Nowadays a 36ft boat is sold with an engine of around 30hp and a 40ft with an engine of about 50hp. These engines on those boats can handle almost all situations, being able to travel exclusively using its engine in most situations.
That engine is not enough only in unusual situations, in gale force winds going windward, etc.

Going to windward in a gale can require considerable more power than often believed. Just maintaining a heading into a seaway might need less power. Sailing craft (and their masters) should not have to be dependent on an engine in a gale.
_____________________________________________________

Originally Posted by Vega

A cat without any sail can be capsized only by the pressure of the wind on the mast. Sure, it is needed a lot of wind, but in a recent ocean race, several capsized that way. For those, that had a massive RM, 70knots is enough.

You might note that these are primarily ocean racing vessels with very tall wing-mast. Those wing mast can present a very sizable 'sail area' by themselves, and up very high. These mast can be particularly troublesome when rotated sideways to the wind in a downwind sailing sitatuation aggravated by a sudden slowing of the vessel at the trough of a wave...watch out, pitchpole!!
_____________________________________________________

Originally Posted by Vega

Of course this can be overcome if you use smaller rigs, but then the sailing performance will suffer.

Smaller rigs in comparision to what...the racing boats? Just use lower aspect ratio rigs....Marchaj had lots of praise for these style rigs in a cruising situation. In fact there driving power was superior to that of the hi-aspect ratio when beam-to the wind, or off the wind....most favored cruising aspect.
Besides a smaller sailed multi, even a fat one, will often outsail its similar length monohull.
____________________________________________________

Originally Posted by Vega

There are other options: one is to consider a rig not normally used in cats, a Gaff rig with a big bowsprit; another is to use a variant of a Latin rig (Catalans have a race with traditional boats that have to use Latin rigs. It’s incredible the performance and the upgrades they have introduced in that rig). These types of rigs without sails are a lot shorter, for the same sail area, therefore they will offer a smaller resistance to the wind.

Obviously I will agree with you there, other rig options....witness my alternative rig ventures:
http://www.runningtideyachts.com/sail/

But realize what a VERY tough sell it is to the very conservative sailing market who has been told that the modern sloop rig is God!! And multihulls are still fighting old conservative beliefs.
________________________________________________
Ocean Capable?

At the end of this MotorSailing Posting I repeat, "“This work (tank testing at Southampton Univ by Lock Crowther) has indicated that the well designed catamaran is remarkably safe in breaking waves up to considerable height, even when beam on, we were unable to capsize a power catamaran yacht in the largest wave which could be generated. This corresponded to a 52' wave for a catamaran of 40' beam. Scaling this down to a typical 24' beam cruising cat means she should be O.K. in a 31' breaking beam sea. An equivalent size mono-hull power boat was easily capsized by a 25' breaking sea, and in tests with conventional yachts after the Fastnet disaster, it was found that a 40' mono-hull yacht could capsized in a 12' breaking sea.” Added note:And with a mast (bare) the stability is generally improved.
____________________________________________________
Just as an aside, you might find this interesting, "Herreshoff's catamaran reasoning"

[Guillermo]

Originally Posted by brian eiland

...We need to modernize the motorsailer. The multihull plan-form holds great promises to improve this breed. The long slender hulls of the catamaran type vessel have proven themselves to be real efficient to push under both power & sail. And not only are they efficient, but they can be pushed beyond the traditional hull-length/speed limitations. Just what the modern motorsailer needs, a far less compromising increase in both their sail & power performance, while maintaining an economy of operation that allows truly long range capability....

I've found almost all catamarans with engines, qualify as motorsailers using my 14/14 definition (You already know my pages http://www.xente.mundo-r.com/motorsa...ultihulls.htm), and I agree that is quite difficult to turn turtle a seamanshiply sailed cruising catamaran. So shall we agree with you that they are the paradigma of motorsailers nowadays?
Big minus are probably high marina fees and higher initial cost.....

[FAST FRED]

"By that definition then no power boat should go to sea as they can rolled over rather easy, and don't self-right.'

Many of the older displacement power boats have enough rudimentary balast to make them self righting, just a matter of high buck deck hardware ,good choice of ports and commercial style glass and mountings.OTS

Any motorsailor will be carring ballast and should be able to get back up right from a 180 displacement , as long as she remains intact.

Many, many sailboats have survived knockdowns with out being sunk or dismasted , so the big wave might roll her a few times , but the chance of survival would be hundreds of times the invereted forever catamaran.

AS in all lifes endeavours "you pays your money and takes your chances", but I would prefer the chance a really skinny lead sled gives to the certain problem of the upside down cat.

Most of the cats I have been on stank as ocean crossers as the performance NEVER exceded the expected hull speed of a lead sled. A 65 ft cat cruising at 8k is hardly worth the risk,cost or dock finding hassles and expense.

FAST FRED

[Raggi_Thor]

I think there are differences between coastal cruising and offshore, ocean crossings. How is he movement of a lightweight catamaran?