Motor Sailers?

[sharpii2]

I would like to add my own $0.02.

I read Mr. Leask's post and must say I agree. Its best to travel at sub hull speed if decent range as well as fuel economy is what you're after. In my project boat (The Landing School, '89-'90) It had a small engine, A big feathering propeller, and a gaff cutter rig. the engine was for calms and near calms only and was expected to push the 27ft WL boat at only 4kts. The rig was to be simple and sturdy for it, not the engine, was going to keep you off the beach when things got 'exciting'.

The goal was to use only 1hp per ton much the way the early 20th century ocean liners were designed to do (The Olympic class). This way, my 6 ton boat would use only 1/3rd gallon of diesel per hour (I hope) and would average 12nm per gallon.

The SD of 14.5 was to provide most of the propulsion. In winds of 7kts or more it would do useful work.

During that time, the engine would be off.

To make this work, I specified a feathering propeller which, in my mind, is the greatest invention for sail boats since dacron.

The steel boat was designed to be cylindricly developed and built to work boat, not yacht, standards in both strength and appearance.

It was to be my home afloat and to knock about odd corners of the world.

The goal was never to get there fast, but to get there reliably.

Well. Thats my $0.02 worth.

Bob

[Sean Herron]

Hello...

I hate to get sidetracked from my sidetracking...

Have a look at my doodles...

I like to go as small as possible...

http://www.boatdesign.net/gallery/sh...sort/1/cat/500 - there are others but they seem to shuffle by hit counts...

SH.

[trimix]

I would like to have you opinions about these designs as motorsailers

http://www.gartsideboats.com/catsail6.php

Thanks

[Guillermo]

I like very much your designs, Paul. They are just in the line I think proper motorsailers should be nowadays. Please have a look at my page about motorsailers and motorsailing at: http://banjer37msclub.tripod.com/motorsailing.htm
I've used some info from your boats there and posted links to your web pages.
I'd appreciate your comments on my page.
Regards,
Guillermo.

[trimix]

Guillermo,

Do you know an European designer able to draw a Banjer 37 replica ? Or who already have a replica in his stock plans ?

[FAST FRED]

With the canoe stern the Banjer is NOT a candidate for a modern speedy cruiser.

Fun to look at but doubble enders take far more power to get speed from as the stern squats fast , slowing the transit speeds considerably.

A "tug" style sten that is rounded , so you can spring off pilings etc , is really handy on a distance cruiser , and does not need to slow the boat as the double ender stern does.

FAST FRED

[trimix]

I've something which looks like a Banjer but not perfectly ... See these Bruce Roberts designs S370 B, C, D and Trawler versions !

http://www.bruceroberts.com/public/HTML/S370.htm

Nice isn't it ! But Bruce don't consider them as motorsailer Guilermo could you advice ? DO you think is is possible to transform it as a motorsailer by adding a bigger engine for example ?

[trimix]

I've a reply from Bruce. Spray 370 can be transform as a great motorsailer.

You just have to increase engine power about 4HP for 1000 lbs displacement is a good estimation for him...

Is Banjer 370 have a son ? Maybe Spray 370 !

What's Banjer fans think about ?

Trim

[Guillermo]

Answering FAST FRED:
I know Banjers are not speedy cruisers, nor they pretend to be. They are heavy weight - european style motorsailers, so...
But even with the full displacement hull and canoe stern, they sail reasonably well under sail alone (transoceanique versions, with an SA/D around 14) and they motor quite well with a 61 HP engine, having a top speed in excess of 8 nots and a fuel-efficient speed of 6 knots, wich relates with a Froude's number of 1.03, using around one gallon per hour.
Very nice for long trips, specially taking in account actual and foreseeable fuel prices!
Answering TRIMIX: I do not see SPRAY 37 as being derived from Banjers, as she has totatlly different hull lines, with hard chines and flat stern.

[mackid068]

Bruckmann 50' Motorsailor, that's all I can say about the enclosure. 9kts sail, 11kts power (something of that nature). Search google.

[Guillermo]

Originally Posted by trimix

I've a reply from Bruce. Spray 370 can be transform as a great motorsailer.

You just have to increase engine power about 4HP for 1000 lbs displacement is a good estimation for him...

Is Banjer 370 have a son ? Maybe Spray 370 !

What's Banjer fans think about ?

Trim

I find 4 HP per 1000 lbs quite a high figure for full displacement motorsailers.
I think that something between 2 to 2.25 is good enough, providing an engine with a rated power such that a fuel-efficient speed can be reached using around 60% of it, and having extra muscles for when things get rough.

[brian eiland]

Originally Posted by Guillermo

...big snippet...
My main interest is to discuss about what should be defined as a proper motorsailer. My personal feeling is drifting on the side of "classic" motorsailers, particularly pilothouse motorsailers, with no disrecpect for other conceptions, absolutely. It's only that I feel more comfortable with monohulls than with multihulls, as well as I don't like very much speeds in excess of hull's at sea, as I find we have a bit enough of an speedy way of life on land.

So, my idea of a proper motorsailer is a motoring-bred sailing boat conceived to have a hull-lines/engine/gear/propeller combination as to efficiently attain hull speed when motoring (with a + for headwind beating), and the addition of enough sail area as to to easily clawing off a lee shore and going up to nearly hull speed in a Force 4 breeze. As I see things, no more than an SA/D ratio of 14.

.....I had no notice about these threads about motorsailers at boatdesign.net forums. I'm delighted. Lot's of things to read and learn next weeks.
I agree with Brian that maybe I should have post all this this at the "Munohulls versus Multihulls" thread. Mañana!
Guillermo.

You might have a look at this posting on another similar thread concerning monohull motor sailers http://www.boatdesign.net/forums/sho...7&postcount=79
This thread leads to a pretty good article by Greg Jones of BlueWater Sailing about defining monohull motor sailors, http://www.bwsailing.com/01articles/issue/0405/bwb.htm

[FAST FRED]

" and they motor quite well with a 61 HP engine, having a top speed in excess of 8 nots and a fuel-efficient speed of 6 knots, wich relates with a Froude's number of 1.03, using around one gallon per hour."

A fuel consumption of a gal an hour is about 17 to 20hp, to use a 61hp engine for the rare 8K dash , and then run it most of its life at 1/3 or less the rated hp does NOT make for long & happy engine life.

A 30hp engine would be half the weight and live loads longer with a more realistic 60% loading.

Yes the # of 1.03 is realistic speed for a canoe stern , but a similar heavy (by todays stds) boat with a transom should be able to see # 1.20 , a considerable difference after a weeks motoring.

FAST FRED

[Guillermo]

Originally Posted by FAST FRED

" and they motor quite well with a 61 HP engine, having a top speed in excess of 8 nots and a fuel-efficient speed of 6 knots, wich relates with a Froude's number of 1.03, using around one gallon per hour."

A fuel consumption of a gal an hour is about 17 to 20hp, to use a 61hp engine for the rare 8K dash , and then run it most of its life at 1/3 or less the rated hp does NOT make for long & happy engine life.

A 30hp engine would be half the weight and live loads longer with a more realistic 60% loading.

Yes the # of 1.03 is realistic speed for a canoe stern , but a similar heavy (by todays stds) boat with a transom should be able to see # 1.20 , a considerable difference after a weeks motoring.

FAST FRED

Sorry, Fast Fred, you're right: I made a mistake.
I motor at around 6 knots (calm seas) with my Banjer on long trips. Consumption is around 2 gall/hour, not one.
My Banjer's Perkins 4236 is 34 years old, has more than 10.000 hours on his shoulders, no overhauls, and still running like a darling. Good enough to me :-)

[mackid068]

Let's define a motorsailer! I vote for: A waterbound vessel capable of powering via sail or motor as a 200% capable boat, with both types of power usable as the primary power source.