Single engine vs. twin engine
 

(at the risk of sounding naive, but a question to help clear my
understanding...)

Other than some of the obvious ones ("spare" engine reliability, single
operating engine economy), what are some of the reasons to get a single
engine trawler ( 43 feet) over a twin and vice versa?

There seem to be excellent vessels in both configurations.

Single engine vs. twin engine
 

Cal Vanize wrote:


(at the risk of sounding naive, but a question to help clear my
understanding...)

Other than some of the obvious ones ("spare" engine reliability, single
operating engine economy), what are some of the reasons to get a single
engine trawler ( 43 feet) over a twin and vice versa?

There seem to be excellent vessels in both configurations.

I am talking about diesel engines(s).

Single engine vs. twin engine
 

Cal Vanize wrote:


(at the risk of sounding naive, but a question to help clear my
understanding...)

Other than some of the obvious ones ("spare" engine reliability,
single operating engine economy), what are some of the reasons to get
a single engine trawler ( 43 feet) over a twin and vice versa?


The basic trade-off is speed versus economy.

A lot of people say they feel "more secure" in a twin engine
boat, but the most usual cause of engine malfunction is
either dead battery, fuel problem (lack, big globs of crud,
air leak, etc etc), which would affect both engines in 99%
of cases... or some lack of basic maintenance.

There seem to be excellent vessels in both configurations.


True, but it's a basic difference that in most cases will
profoundly influence how the owner is satisfied. Guys who
like to go fast will not like cruising in a single engine
trawler. Guys who don't like to pay for hundreds of gallons
of fuel will not like cruising (or even riding around for a
few hours) in a twin (unless somebody else is paying for it).

One benefit of the single is that the engine room is much
roomier. This can make a big difference when doing
maintenance, and when upgrading or installing new equipment.
For example, I put a diesel fueled furnace & heaters in our
boat a couple of winters ago... it was difficult to find a
place to install it properly, and our boat is a 36' single
engine with an engine room that I would describe under most
other circumstances as roomy.

A benefit of twins is maneuverability. It's not difficult to
dock a twin engine boat, and usually you can ignore the
finer points of using prop walk. Backing up is a breeze.

Another issue is grounding. If you haven't run aground, you
either haven't been anywhere or are lying. With a single it
is easy to have quite good prop protection. Our boat has a
full keel & skeg and it's difficult to imagine anything
damaging our prop. OTOH while some twins have good
protection, most do not and most will pay for some expensive
damage every couple of years (another scenario in which a
spare engine does little good).

Needless to say, I am better at justifying the "go slow &
cheap" type boat, because that is what we have, and my wife
& I like it a lot.

Single engine vs. twin engine
 

Cal Vanize wrote:

(at the risk of sounding naive, but a question to help clear my
understanding...)

Other than some of the obvious ones ("spare" engine reliability, single
operating engine economy), what are some of the reasons to get a single
engine trawler ( 43 feet) over a twin and vice versa?

There seem to be excellent vessels in both configurations.



Obvious things aside, you can maneuver a twin power boat much more
easily than a single. Add a bow thruster, and you can pretty much make a
boat dance.

-paul

Single engine vs. twin engine
 

Paul Cassel wrote:
Cal Vanize wrote:

(at the risk of sounding naive, but a question to help clear my
understanding...)

Other than some of the obvious ones ("spare" engine reliability, single
operating engine economy), what are some of the reasons to get a single
engine trawler ( 43 feet) over a twin and vice versa?

There seem to be excellent vessels in both configurations.



Obvious things aside, you can maneuver a twin power boat much more
easily than a single. Add a bow thruster, and you can pretty much make a
boat dance.

-paul

With bow and stern thrusters, for the most part, the manuverability
issue goes out the window. For a trawler, where your looking more for
range rather than speed (a twin engine trawler should be faster, but
not dramatically faster), a single engine is really the better choice.
It's also much easier to stay on top of maintanace with a single diesel
rather than twins, better access to both sides of a single engine
really helps. And their's a lot more room in the engine room on a
single vs a twin to add other things to the boat like water makers,
generators, A/C units, ect.. And when it comes time for replacement of
the engine, a single is much less painfull when the bill comes due.

In the end, it all comes down to what do you want. Some will swear by
twins, others wouldn't give up their single. You have to pick which one
is right for you.

John

Single engine vs. twin engine
 

On Sat, 25 Nov 2006 20:12:54 -0600, Cal Vanize
wrote:

Other than some of the obvious ones ("spare" engine reliability, single
operating engine economy), what are some of the reasons to get a single
engine trawler ( 43 feet) over a twin and vice versa?

It depends on your priorities.

Single engine trawlers offer the best fuel economy, less maintenance,
better prop protection and more space in the engine room.

Twin engines offer better ultimate reliability in terms of being able
to get home after an engine failure, and better maneuverability in
close quarters without the expense and maintenance of thrusters.

It is interesting to observe that Nordhavns, arguably the best long
range trawlers in current new production, are generally single main
engine with a small "get home" engine off to the side with seperate
shaft and folding prop.

For what its worth, I opted for twin engines because I like the
redundancy and maneuverability. The redundancy aspect has already
made itself useful on each of my last two boats. With engine failure
it's not a matter of "if" it will happen, but when and where it will
happen.

Single engine vs. twin engine
 

Single with a bow thruster is more maneuverable than a twin. Half the
maintenance and fuel costs, lots more room in the engine room, etc.
Lots of commercial boats are singles. That was my choice, and would be
again in the future.

Single engine vs. twin engine
 

"Keith" wrote in news:1164714834.883384.235120
@l12g2000cwl.googlegroups.com:

Lots of commercial boats are singles.

950' containerships are singles, too.

38,800 hp, 7 cyl, 110 RPM, no transmission singles (SeaLand "Performance")

What a monster. Only burns 75 tons of heavy oil a day...





Oh, it's a 2-stroke!...(c;

5 ft bore....7 ft stroke....serious power.

Larry
--
If we eliminate religion, will they stop murdering each other?

Single engine vs. twin engine
 

On 28 Nov 2006 03:53:54 -0800, "Keith"
wrote:

Single with a bow thruster is more maneuverable than a twin.

I've never maneuvered a boat with a bow thruster so I can't speak from
personal experience on that one. I've watched a number of other
people however, and either some thrusters are a lot more capable than
others, or some people are a lot more capable than others. :-)

I may be wrong about this but it seems to me that a single engine boat
will always be disadvantaged at certain maneuvers because of prop
walk, ie, the boat will favor one side over the other when backing and
turning. I am aware that experienced captains allow for this in
advance and plan accordingly, but no such issue exists for twin engine
boats which was the basis for my original statement. With experience,
twin engine boats can be walked sideways in either direction which
leads some people to think we do have thrusters. We can also maneuver
in place, ie, turn in either direction with no forward or reverse
motion. That is difficult to do using only bow thrusters.

There was a well publicized incident in Bermuda two years ago on the
Nordhavn transatlantic rally. On the day of departure there was a
strong northerly blowing boats against the dock in Hamilton Harbor at
the RBYC. Several boats had a great deal of difficulty maneuvering
off of the dock because their thrusters were not strong enough to
overcome the force of the wind. While it could be argued that they
should have used spring lines and prop thrust to push them off, this
would have been a no brainer with twin engines, and no spring lines
would have been required.