Robert Straghan wrote:
I have commissioned a Diesel Duck 462 from Seahorse Marine in China, as a
replacement for my troller. One available option is a motorsailer rig that
increases overall sail area from 377 to 754 sq. ft.

My interest is in fuel economy in the face of never ending fuel costs. I
would rather bite the bullet now and save fuel in the long run. My problem in
justifying the cost is the incremental advantage gained by the bigger rig over
the standard N/C rig.

I realize that this is not a sailboat, and could be described as a powerboat
with sails. Performance under sail to windward will be poor to useless, and
performance under sail alone poor. These facts do not bother me too much as
the operational paradigm will be sails up and the engine ticking over. Aside
from fuel economy, I would hope so see the sails assisting paravanes in roll
attenuation, and provide a secondary means of propulsion in the event of
engine problems.

Any comments on trawlers with sails?

Robert Straghan
Ocean Tigress - Wahl 52 ft. troller

Brian replied:
Trawlers with Sails (was sail rig)

This reminds me of something I wrote recently, "I really can appreciate a lot
of these new ideas in the 'motorsailer theme'. I believe that many marketing
people are waking up to the reality that the already small sailing population
is on a decline and gravitating toward faster cruising forms in power and/or
sail. Some of this is a result of the older population deserting sail for a
trawler. Some of this is the younger population not content with slow cruising
in this fast paced world...they may only have the weekends to work with. I
think some of the renewed interest in the motorsailer concept is the result of
these observations...so they say lets add some more OOMPH in our sailboats.
But be cautious, adding bigger and bigger engines, or twin engines does not a
motor sailer make.

Likewise, adding a sail to a trawler does not a motor sailer make. In fact
this reverse configuration can be more problematic. The sail rig has a certain
drag associated with itself, and the high freeboard/profile trawler shape even
more drag. For the sail rig to provide any propulsive effort on the trawler it
must overcome these two drag factors first. You begin to require a fair size
rig that then requires counter ballast, making our trawler even heavier and
possible deeper draft. Sail rigs on trawlers are 'steadying rigs' reducing
rolling motions. Don't ask them to propel the vessel. Alternately consider a
Motor Sailer.

...some more of that other discussion...
Adding a bigger and bigger engine (or twins) is not the most efficient
solution, although it does more truly exist as a MOTORsailer. As you said, "A
big engine will only mean you will be able to maintain speed in adverse
conditions: You won't go any faster" I think you made a very important
observation, "Accept that the virtue of a motorsailer is that you can make
higher average speeds, which is done by eliminating the slow speeds and
continuing to make decent way even in the absence of wind." In other words
bigger engines for faster top end speeds aren't the answer in defining the
monohulled motorsailer, even thought the marketing guys would have you believe
so. And the real virtue of twin engines is maneuverability and 'back up'
propulsion source. But wait a minute, in a motorsailer our back up propulsion
source is the sailing rig, so twin engines is overkill in most situations.

I start to see a trend here similar to what is happening in the trawler world.
There seems to be an increasing demand by the public for just a little more
speed than that offered by the truly efficient displacement trawler. So now we
see more and more twin-engined trawlers, with greater and greater HP, that in
reality are going beyond the definition of trawler...they are becoming
motoryachts in trawler clothing. (aka, wolf in sheep's clothing)

The crux of the problem is when we try to overcome some basic laws of nature
in trying to push the monohull form pass it's 'hull speed' in an efficient
manner, whether power or sail. Sorry, but it just takes more power and some
'planning surfaces' to do it. Alternatively we can look at pushing longer
slimmer shapes that exhibit less hull speed resistance. In the sail mode we
have to space these slimmer hulls apart some considerable distance to get
stability to carry the sailplan. In the power mode this wide separation is not
required necessary.

Brian Eiland

beiland@usa.net
http://www.RunningTideYachts.com
distinctive multihull expedition yachts

Back when "Portager" was a mere 36' boat I was considering a sail as a get
home drive and I researched the options quite throughly. I finally gave the
sail up because of trailering issues and the effort to erect/stow every time
I went to trailer it.

I believe the Dashew's did an excellent job of showing the cost savings
fallacy of a "Bermuda" type rig
http://www.setsail.com/dashew/Operating_Costs.html , however my research
showed that a Junk rig is much lower cost and the sails are easier to handle
with a small crew. Another advantage of the Junk sail is they are fully
battened so you do not need as much height to get the same sail area, which
reduces the ballast requirements. The battens also reduce the stress in the
rig allowing you to use lighter/cheaper fabric and making them easy to reef.
Finally the Junk rig uses an unstayed mast, which is simpler, less
maintenance and easier to stow for bridge clearance.

I think a sailing rig is a good option if you are looking for more roll
stabilization or a last resort get somewhere drive (maybe not home, depends
of the winds since performance to windward will be questionable) but if you
are looking to save money I think the most cost effective sail is he one
left on the drawing board. If you still want a sail, I recommend you look
closely at a Junk sail and have a naval architect help you design it into
the boat to assure you get the best performance and reasonable aesthetics.

Good luck, I think, with the right approach a Duck might look good with a
Junk sail, and it shouldn't be hard to find one in China.

Regards;
Mike Schooley
Designing "Portager" a transportable Passagemaker