Motor Sailers?

[SAQuestor]

Originally Posted by Guillermo

And also from Nordhavn:
http://www.nordhavn.com/news/pressre...torsailor.php4

Ah yes. I'll think about buying a lotto ticket for tonight's drawing. Probably should wait to see if it's a winner before placing an order.

[Vega]

This one seems different. They call it “A fast Sailmotor”. While motoring they advertise a max speed of around 18k and an economical cruising speed between 12 and 15k with a 140hp engine.

What seems remarkable is that the boat seems also to be a good sailingboat. The hull seems to be very close to a sailing boat hull and with a LWL of 13,5m a Displacement of 11T, a sail area of 98 m2 and retractable fin keel with a bulb with a max draft of 2.9m, that boat is probably a fast sailing boat.

http://www.stefini.com/broc_tec.pdf

[yipster]

long time vega, nice looking boat allright, good claims also yet why havent i seen a motersailor or sailermoter looking like a better motorboat? why do with the stancions and wire, why motor with a big mast up, think it can be better and drew up my fantasy of a motorsailer, i have my doubts sleeping good in the fwd kingsize beds under the pilothouse (i like CG) yet you may like sleeping in it feeling the ride? http://www.boatdesign.net/gallery/sh...6/limit/recent

[westlawn5554X]

I think that is a very interesting sleek boat. Wave piecing for better speed and large storage for toys with cosmetic can be use for weight lifting equipment... WALLY is watching and I bet it is different unquiely YIPSTER. Well done, but I didnt see the hull part, cat or tri? More cat it seem, the centre hull is not in the water?

[Ari]

Indonesian style motorsailor

http://www.boatdesign.net/gallery/sh...0/ppuser/12573

[yipster]

http://www.ship-technology.com/proje...t/devcat3.html

Originally Posted by westlawn5554X

WALLY is watching

really think so? e-mailed incat few weeks back bout hull ideas but seems their gone ofline? http://www.incat.com.au/
below a rough 150m2 sailplan with belowdeck furlers

[Vega]

Yipster, after looking to your motorsailor I have to say that after all the one that I posted is quite vulgar

Your boat is the one that "is" different.

[yipster]

meaning a compliment yes? car is wrong, not a wrong car but what was it again your driving, should match better

[Guillermo]

Some figures for the Stefini 13.50, as calculated using their site's data and my own interpretation for the not available:

Beam/Length Ratio, B/L = 2,74
Ballast/Disp Ratio, W/Disp = 0,19
Displacement/Length Ratio, D/L = 119,03
Sail Area/Disp. Ratio, SA/D = 20,77
Power/ Disp. Ratio, HP/D = 6,04 HP/ton
Hull speed, HSPD = 8,92 Kn
Potential Maximum Speed, PMS = 10,3 Kn
Velocity Ratio, VR = 1,15
Capsize Safety Factor, CSF = 2,28
Motion Comfort Ratio, MCR = 19,5
Heft Ratio, HF = 0,61
Angle of Vanishing Stability, AVS = 112 º
Roll Period, T = 2 Sec
Roll Acceleration, Acc = 0,35 G's
Stability Index, SI = 0,4

Nice to play around in summertime, Marina to Marina day sailings, sleeping ashore (slosh under the flat stern needed to speed up to 20 kn must be annoying).

Designer states: ....aiming to satisfy many "impacient sailors" switching to motor because lack of time...A whole lot of a philosophy...

[Vega]

Originally Posted by yipster

meaning a compliment yes?

Yes

[Vega]

Originally Posted by Guillermo

Some figures for the Stefini 13.50, as calculated using their site's data and my own interpretation for the not available:

Ballast/Disp Ratio, W/Disp = 0,19

Angle of Vanishing Stability, AVS = 112 º Real:

Nice to play around in summertime, Marina to Marina day sailings, sleeping ashore (slosh under the flat stern needed to speed up to 20 kn must be annoying).

Designer states: ....aiming to satisfy many "impacient sailors" switching to motor because lack of time...A whole lot of a philosophy...

Guillermo, if that AVS was real, I would agree with you, but I can not understand how you have estimate it, the same for the Ballast/Disp Ratio of 19%.

The boat has a light weight of 8.5T and a deep lead bulb (around 3m deep) that looks to weigh about 1.5 to 2T. You can add about 0.5T more for the rest of the keel, but you don't know the percentage of interior ballast. Furthermore, the designer says that the weight of the bulb will vary to compensate the differences in weight of the different motorizations. That boat can have engines between 120hp and 300Hp.

Giving the experience and seaworthiness of his previous oceangoing boats, I would very much doubt that the AVS of the boat is only 112º. Probably the AVS will follow what is normal in this type of hulls; I mean a value between 120º and 130º.

This boat, with tanks for 800L of fuel, 800L of water and provision for a watermaker and generator is clearly not designed to "play around in summertime, Marina to Marina day sailings, sleeping ashore ".

The 19k of speed is only possible with a very unreasonable (in my opinion) 300hp engine. If you have the standard 120hp engine you will only get 12k of speed, with a reasonable consumption, and that, without being anything out of this world, would be nice, depending on the consumption, of course.

But what is really nice (for me) on this motorsailor is that, like they advertise, it is more a sailmotor, meaning that it is first a good sailing boat and second, a boat that has a reasonable and economical performance as a motorboat.

[Guillermo]

Paulo,

Sorry for the "Real" word appearing after AVS. A transcription mistake, as I had used the spreadsheet for another boat for which I knew the real AVS and noted it down by the side of the estimated one. Copying and pasting afterwards brought that wrong post. I've already delete it. Sorry again.

AVS estimated by the usual formulas doesn't pretend to be the real thing as it doesn't take into account reserves of buoyancy due to superstructures, etc., but only give a clue to compare boats.

As an example, Eric Sponberg's Globetrotter 45 has an estimated (by this method) AVS of 117º, but a more precise (also estimated, but developing the GZ curve) AVS of 137º because of its big volumes over deck.

Estimated Ratios are that: Figures of merit to compare boats, not the real thing.

But not knowing the real thing, thanks to the estimated numbers we may compare Eric's boat or any boat with any other boat, and get a picture of the comparative expectable performance of both boats. That's the only pretention, which is no little.

About the Stefini, I worked with available numbers at the site. Ballast/displacement ratio is a guess, taking into account similar boats with deep bulbed keels.

I do not like that concept of boat, but I do not pretend others following my wake. It's only that I don't like it and, as so, I say it.

(Well: To be more precise, I don't like it as an all around motorsailer. But I can admit it may be fun for precisely the use I intended to exemplify with the "play around...etc phrase")

[Guillermo]

A very nice one from Dick Koopman, Aerorigged.
http://www.dickkoopmans.nl/uk/index.htm Go to "New Proyects"

Here some numbers for her:
Beam/Length Ratio B/L = 2,93
Ballast/Disp Ratio W/Disp = 0,39
Displacement/Length Ratio D/L = 398,75
Sail Area/Disp. Ratio SA/D = 11,44
Power/ Disp. Ratio HP/D = 2,33 HP/ton (guessed)
Hull speed HSPD = 8,33 Kn
Potential Maximum Speed PMS = 7,71 Kn
Velocity Ratio VR = 0,93
Capsize Safety Factor CSF = 1,55
Motion Comfort Ratio MCR = 55,27
Heft Ratio HF = 1,68
Angle of Vanishing Stability AVS = 120 º
Roll Period T = 5,13 Sec
Roll Acceleration Acc = 0,05 G's
Stability Index SI = 1,17

This one seems like being very comfortable at sea and well mannered. S/D ratio seems low, to my taste, but maybe these ratios do not work well with Aerorigs....

[Vega]

I like this one, the Fairwind 46. A steel hull boat (radius chine) that looks traditional and modern at the same time.

It is a John Butler & Associates design.

http://www.fairwindyachts.com/

[VASCONY]

Originally Posted by Viceroy

I'm familiar with the majority of conventional motor sailers, mostly the European models (Fisher, Nauticat, etc.) but feel there is still room for improvement. In the world of aging sailors, the comfort of an enclosed pilothouse and inside stearing is more than appealing to this group. My ideal vessel would reduce the compromises of good sailing and good motoring characteristics. Further, in the 38' - 45' range, a couple should be able to comfortably operate and live aboard for extended periods with the conveniences of most shore-side systems. Only occassional, short-term guests would be on board so separate cabins and heads would be eliminated, in favour of one large master stateroom and head/shower/bath. A couple of sea berths would be sufficient. The pilot house would have comfortable seating and a dining area with ports/windows to enjoy the view. Despite these windows - storm covers - the vessel should be capable of ocean passages. In addition to good sailing, an engine should be powerful enough to give a good turn of speed in an engine room that provides ease of maintenance...with room for a generator, water maker, furnace/hot water heater and bank or batteries.
Question...are there any new designs and builders devoted to motor sailing vessels as described?
Cheers, Richard.

Hi Viceroy, I'm sharing the same concept. Why don't you check Cabo Rico 38' and Northeast 400 at
www.caborico.com
Cheers