On Wed, 1 Aug 2007 08:36:11 -0400, "Roger Long"
wrote:

I've gone around the diesel electric question on a few research vessels
where it is a good solution.

It is going to be quite expensive.

It makes most sense when the loads while the boat is not moving are a
significant percentage of propulsion loads. This doesn't fit the ususal
cruiser profile (except maybe for Skip and Lydia

You had better have a builder who really understands it. There are going to
be some complex boxes and equipment in between the generators and the props.
Keeping them cool and dry will be a challange. The wiring will be unlike
anything most builders have seen.

It's going to take up a lot more space than a conventional propulsion plant.
There will be some effeciency losses so you will need to carry more fuel on
a boat that already is devoting extra space and weight to this enthusiasm.

When you have problems with it and pull into Pango Nowhere, it's going to
be amusing watching the locals trying to figure out how to fix it.

I love diesel electric but it would not have crossed my mind to try it in a
60 foot sailboat. If having a DE sailboat is a goal in itself because you
like to tinker and want to be a pioneer, cool. If you just want to sail and
cruise, I would forget it. You can use that space, weight, money, and
research effort much more usefully.


There was an article in "PassageMaker" a while back about the
conversion of a trawler yacht from diesel to diesel-electric. It,
frankly, looked like a corporate promotion article -- perfectly
lighted photos and from the prospectives , obviously professional
camera equipment, but anyway.

The crux of the article was that the owner removed two main engines
and replaced them with a single, larger prime mover driving either an
alternator or generator (I don't remember which way he got his
electricity). Each of the original propellers/shafts, etc, were
replaced by DC motors directly coupled to the shafts. The whole
caboodle was SCR controlled and the genrator/alternator and both DC
drive motors were water cooled. The electric controls looked similar
to the SCR controls in an off shore drilling rig.

From looking at the pictures there appeared to be little of the
installation that was "off the shelf" and my guess was that the whole
installation must have been far in excess of what the original twin
engine installation was.






Bruce in Bangkok
(brucepaigeATgmailDOTcom)

Roger & Bruce; thanks for your reaction. Pioneering is nice.. but not at any
price ;-) Not my main reason for looking into this...

My main objectives are :
- having a backup engine with which she should at least run 4 kn without
having the need for double propellors (too much drag it's a fast sailing
yacht nog an moto sailor ;-)
- not needing a seperate generator by using one of the main engines as a
generator
- less noise / vibration?

Hope to get in contact with someone who has a 60 or 70 foot sailing yacht
running with diesel eletric propulsion. If there is any :-)

Grtz Marc
sy Beluga
wrote in message
...
On Wed, 1 Aug 2007 08:36:11 -0400, "Roger Long"
wrote:

I've gone around the diesel electric question on a few research vessels
where it is a good solution.

It is going to be quite expensive.

It makes most sense when the loads while the boat is not moving are a
significant percentage of propulsion loads. This doesn't fit the ususal
cruiser profile (except maybe for Skip and Lydia

You had better have a builder who really understands it. There are going
to
be some complex boxes and equipment in between the generators and the
props.
Keeping them cool and dry will be a challange. The wiring will be unlike
anything most builders have seen.

It's going to take up a lot more space than a conventional propulsion
plant.
There will be some effeciency losses so you will need to carry more fuel
on
a boat that already is devoting extra space and weight to this enthusiasm.

When you have problems with it and pull into Pango Nowhere, it's going to
be amusing watching the locals trying to figure out how to fix it.

I love diesel electric but it would not have crossed my mind to try it in
a
60 foot sailboat. If having a DE sailboat is a goal in itself because you
like to tinker and want to be a pioneer, cool. If you just want to sail
and
cruise, I would forget it. You can use that space, weight, money, and
research effort much more usefully.


There was an article in "PassageMaker" a while back about the
conversion of a trawler yacht from diesel to diesel-electric. It,
frankly, looked like a corporate promotion article -- perfectly
lighted photos and from the prospectives , obviously professional
camera equipment, but anyway.

The crux of the article was that the owner removed two main engines
and replaced them with a single, larger prime mover driving either an
alternator or generator (I don't remember which way he got his
electricity). Each of the original propellers/shafts, etc, were
replaced by DC motors directly coupled to the shafts. The whole
caboodle was SCR controlled and the genrator/alternator and both DC
drive motors were water cooled. The electric controls looked similar
to the SCR controls in an off shore drilling rig.

From looking at the pictures there appeared to be little of the
installation that was "off the shelf" and my guess was that the whole
installation must have been far in excess of what the original twin
engine installation was.






Bruce in Bangkok
(brucepaigeATgmailDOTcom)

"Marc" wrote


My main objectives are :
- having a backup engine with which she should at least run 4 kn without
having the need for double propellors (too much drag it's a fast sailing
yacht nog an moto sailor ;-)

You already have the back up. They are called sails. If a diesel used in
auxilliar sailboat service doesn't run, it is as apt to be a fuel problem as
anything else. Your second engine will then be down as well.

- not needing a seperate generator by using one of the main engines as a
generator
- less noise / vibration?

A big generator is going to be noiser than a small one. One large enough to
drive the boat is going to be big. Air supply and exhaust are major and
hard to control noise sources. Bigger generators just make it even more
difficult.
Generator's are not happy running at light loads. Unless your hotel load
approaches 50% of your propulsion load running just the one generator for
ship's service will probably result in it's running too lightly. If you do
put in enough hotel load, AC, Jacuzzi, etc., to load up the generator, where
are you going to carry all the fuel?


Hope to get in contact with someone who has a 60 or 70 foot sailing yacht
running with diesel eletric propulsion. If there is any :-)

I'll be amazed if you find one for the above reasons. If you do, please let
us know.

Grtz Marc
sy Beluga
wrote in message
...
On Wed, 1 Aug 2007 08:36:11 -0400, "Roger Long"
wrote:

I've gone around the diesel electric question on a few research vessels
where it is a good solution.

It is going to be quite expensive.

It makes most sense when the loads while the boat is not moving are a
significant percentage of propulsion loads. This doesn't fit the ususal
cruiser profile (except maybe for Skip and Lydia

You had better have a builder who really understands it. There are going
to
be some complex boxes and equipment in between the generators and the
props.
Keeping them cool and dry will be a challange. The wiring will be unlike
anything most builders have seen.

It's going to take up a lot more space than a conventional propulsion
plant.
There will be some effeciency losses so you will need to carry more fuel
on
a boat that already is devoting extra space and weight to this
enthusiasm.

When you have problems with it and pull into Pango Nowhere, it's going
to
be amusing watching the locals trying to figure out how to fix it.

I love diesel electric but it would not have crossed my mind to try it in
a
60 foot sailboat. If having a DE sailboat is a goal in itself because you
like to tinker and want to be a pioneer, cool. If you just want to sail
and
cruise, I would forget it. You can use that space, weight, money, and
research effort much more usefully.


There was an article in "PassageMaker" a while back about the
conversion of a trawler yacht from diesel to diesel-electric. It,
frankly, looked like a corporate promotion article -- perfectly
lighted photos and from the prospectives , obviously professional
camera equipment, but anyway.

The crux of the article was that the owner removed two main engines
and replaced them with a single, larger prime mover driving either an
alternator or generator (I don't remember which way he got his
electricity). Each of the original propellers/shafts, etc, were
replaced by DC motors directly coupled to the shafts. The whole
caboodle was SCR controlled and the genrator/alternator and both DC
drive motors were water cooled. The electric controls looked similar
to the SCR controls in an off shore drilling rig.

From looking at the pictures there appeared to be little of the
installation that was "off the shelf" and my guess was that the whole
installation must have been far in excess of what the original twin
engine installation was.






Bruce in Bangkok
(brucepaigeATgmailDOTcom)

So... you might be right. No reason for me to look into this option any
further. Spend my money on a good main engine and a nice small generator and
saving a lot for extended cruising time ;-)

"Roger Long" wrote in message
...

"Marc" wrote


My main objectives are :
- having a backup engine with which she should at least run 4 kn without
having the need for double propellors (too much drag it's a fast
sailing yacht nog an moto sailor ;-)

You already have the back up. They are called sails. If a diesel used in
auxilliar sailboat service doesn't run, it is as apt to be a fuel problem
as anything else. Your second engine will then be down as well.

- not needing a seperate generator by using one of the main engines as a
generator
- less noise / vibration?

A big generator is going to be noiser than a small one. One large enough
to drive the boat is going to be big. Air supply and exhaust are major
and hard to control noise sources. Bigger generators just make it even
more difficult.
Generator's are not happy running at light loads. Unless your hotel load
approaches 50% of your propulsion load running just the one generator for
ship's service will probably result in it's running too lightly. If you
do put in enough hotel load, AC, Jacuzzi, etc., to load up the generator,
where are you going to carry all the fuel?


Hope to get in contact with someone who has a 60 or 70 foot sailing yacht
running with diesel eletric propulsion. If there is any :-)

I'll be amazed if you find one for the above reasons. If you do, please
let us know.

Grtz Marc
sy Beluga
wrote in message
...
On Wed, 1 Aug 2007 08:36:11 -0400, "Roger Long"
wrote:

I've gone around the diesel electric question on a few research vessels
where it is a good solution.

It is going to be quite expensive.

It makes most sense when the loads while the boat is not moving are a
significant percentage of propulsion loads. This doesn't fit the ususal
cruiser profile (except maybe for Skip and Lydia

You had better have a builder who really understands it. There are
going to
be some complex boxes and equipment in between the generators and the
props.
Keeping them cool and dry will be a challange. The wiring will be
unlike
anything most builders have seen.

It's going to take up a lot more space than a conventional propulsion
plant.
There will be some effeciency losses so you will need to carry more fuel
on
a boat that already is devoting extra space and weight to this
enthusiasm.

When you have problems with it and pull into Pango Nowhere, it's going
to
be amusing watching the locals trying to figure out how to fix it.

I love diesel electric but it would not have crossed my mind to try it
in a
60 foot sailboat. If having a DE sailboat is a goal in itself because
you
like to tinker and want to be a pioneer, cool. If you just want to sail
and
cruise, I would forget it. You can use that space, weight, money, and
research effort much more usefully.


There was an article in "PassageMaker" a while back about the
conversion of a trawler yacht from diesel to diesel-electric. It,
frankly, looked like a corporate promotion article -- perfectly
lighted photos and from the prospectives , obviously professional
camera equipment, but anyway.

The crux of the article was that the owner removed two main engines
and replaced them with a single, larger prime mover driving either an
alternator or generator (I don't remember which way he got his
electricity). Each of the original propellers/shafts, etc, were
replaced by DC motors directly coupled to the shafts. The whole
caboodle was SCR controlled and the genrator/alternator and both DC
drive motors were water cooled. The electric controls looked similar
to the SCR controls in an off shore drilling rig.

From looking at the pictures there appeared to be little of the
installation that was "off the shelf" and my guess was that the whole
installation must have been far in excess of what the original twin
engine installation was.






Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Wed, 1 Aug 2007 16:44:41 +0200, "Marc" wrote:

Roger & Bruce; thanks for your reaction. Pioneering is nice.. but not at any
price ;-) Not my main reason for looking into this...

My main objectives are :
- having a backup engine with which she should at least run 4 kn without
having the need for double propellors (too much drag it's a fast sailing
yacht nog an moto sailor ;-)
- not needing a seperate generator by using one of the main engines as a
generator
- less noise / vibration?

Consider putting a folding or feathering prop on the "wing" engine to
minimize drag. Mount two large alternators on each engine (200+amps),
and use them to drive a large battery bank and redundant inverters.
That will be much cheaper to build and service than a diesel electric
system, and will give you full backup for everything. Many long range
cruising trawlers are being built that way.

On Wed, 01 Aug 2007 21:00:52 -0400, Wayne.B
wrote:

On Wed, 1 Aug 2007 16:44:41 +0200, "Marc" wrote:

Roger & Bruce; thanks for your reaction. Pioneering is nice.. but not at any
price ;-) Not my main reason for looking into this...

My main objectives are :
- having a backup engine with which she should at least run 4 kn without
having the need for double propellors (too much drag it's a fast sailing
yacht nog an moto sailor ;-)
- not needing a seperate generator by using one of the main engines as a
generator
- less noise / vibration?

Consider putting a folding or feathering prop on the "wing" engine to
minimize drag. Mount two large alternators on each engine (200+amps),
and use them to drive a large battery bank and redundant inverters.
That will be much cheaper to build and service than a diesel electric
system, and will give you full backup for everything. Many long range
cruising trawlers are being built that way.

You are talking about a 60 ft. sail boat. right?

Generally sail boats have auxiliary engines for those times that the
wind doesn't blow. There are also motor-sailers with somewhat bigger
engines but they really don;t go much faster.

I'm assuming that you will have a modern fin keel, broad beam, shallow
hull depth, type of boat with minimum skin friction. I did a really
quick calculation, assuming 20,000 lbs. displacement and came up with
45 shaft H.P., Shaft RPM of 1100 and a speed of about hull speed.

Now, that is probably a bit underpowered as you will be going "up
hill" sometimes but say you add another 25 - 30% and you still aren't
talking about a very big engine.

You've already decided on a sail boat so you have one source of power
and a secondary, the auxiliary diesel. Now do a little research. Go
down to the commercial docks and see how many commercial boats, guys
that spend their whole lives on the water, have more then one source
of moving the boat. The world's fishing fleet is probably 99% single
diesel engine powered and if you've ever been on the Grand Banks in
the winter time that alone should convince you that a second engine is
not really vital to life and happiness.

Lastly, if you are like most owners of 60 ft. bespoken yachts you are
not in the first blush of youthfulness so either you have a crew or a
really strong wife or you are going to need powered winches. So you
have to figure on a gen-set that runs much of the time, if only to
operate the autopilot.

So there you go. A sixty ft. mast and enough dacron to build a circus
tent, a 75-100 H.P. auxiliary engine and a generator set.

And round the world you go =:-)


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Thu, 02 Aug 2007 18:16:04 +0700, wrote:

So there you go. A sixty ft. mast and enough dacron to build a circus
tent, a 75-100 H.P. auxiliary engine and a generator set.

My point was that if you put a couple of *big* alternators on each
engine you don't really need a generator, and what would have been the
generator engine can now drive an off center shaft with a folding
prop. That way you can have it all more or less. If you want super
reliability, it is also necessary to have seperate fuel tanks for each
engine with appropriate transfer and filtration plumbing, along with
seperate batteries, etc.

Your engine sizing estimates do not take windage into account which
can be considerable on a 60 footer trying to motor into a 30 or 40 kt
headwind. And yes, sometimes it is necessary. I also take some issue
with your comparison to single engined commercial boats. Those boats
almost always have spacious engine rooms with room to work, lots of
essential tools and spares, and someone aboard who knows how to get
the job done. That is not the case with most 60 foot sailboats that
I've seen.

On Thu, 02 Aug 2007 10:40:27 -0400, Wayne.B
wrote:

On Thu, 02 Aug 2007 18:16:04 +0700, wrote:

So there you go. A sixty ft. mast and enough dacron to build a circus
tent, a 75-100 H.P. auxiliary engine and a generator set.

My point was that if you put a couple of *big* alternators on each
engine you don't really need a generator, and what would have been the
generator engine can now drive an off center shaft with a folding
prop. That way you can have it all more or less. If you want super
reliability, it is also necessary to have seperate fuel tanks for each
engine with appropriate transfer and filtration plumbing, along with
seperate batteries, etc.

Not to start a war, but I still don;t understand why you want sails
and two motors...

Your engine sizing estimates do not take windage into account which
can be considerable on a 60 footer trying to motor into a 30 or 40 kt
headwind. And yes, sometimes it is necessary. I also take some issue
with your comparison to single engined commercial boats. Those boats
almost always have spacious engine rooms with room to work, lots of
essential tools and spares, and someone aboard who knows how to get
the job done. That is not the case with most 60 foot sailboats that
I've seen.


Well, I did admit that it was a quick and dirty calculation. But, if
you have 30 - 40 Kts of wind you've got super sailing weather for a 60
ft. boat.

You are right about engine rooms but I'm not so sure about people who
know how to get the work done. Example: The average Thai fishing boat,
say 50 - 60 ft. that makes voyages to Indonesia or Bangladesh to poach
fish usually had a Thai Captain, maybe a Thai 1st Mate, and the rest
of the crew are Burmese who are hired for probably less then $100 a
month. I'm not so sure about their expertise.

But, you have hit the nail on the head -- there are vast quantities of
people driving around in boats that don't know a thing about the
hardware. The neighbor boat to me had some people working on it, I
asked the Owner what was doing and he told me he was having the engine
oil and filters changed. A nice guy but didn't know where the oil
filter was.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Fri, 03 Aug 2007 08:45:38 +0700, wrote:

Not to start a war, but I still don;t understand why you want sails
and two motors...

Well, they weren't my specs but I can understand the motivation.

Let's start with the premise that a boat needs aux propulsion for
various good reasons - entering harbors; short handed sailing with one
or two people; lack of wind; wind in wrong direction; schedules to
meet; broken furling gear; etc. These things all occur in real life
as opposed to the "ideal".

Let's additionally assume that a modern 60 foot boat also needs a
generator to provide power for air conditioning, refrigeration,
freezers, emergency battery charging, entertainment equipment,
microwave oven, etc. So that's one way of getting to two engines that
most folks on a well appointed 60 footer would not argue with.

Now that you've got two engines, how do you provide backup
functionality if one breaks down? Hence my suggestion for heavy duty
alternators on each allowing them to do double duty as power
generators and back each other up in that role. In addition, I would
also equip the second engine with an off center shaft and
folding/feathering prop which allows it to serve as back up to the
primary aux engine.

Modern boats with modern conveniences have a lot of complexity, and
the more redundancy the better in my experience. My own cruising boat
these days is a trawler with all the back up systems I can manage -
twin engines, twin generators, multiple battery banks, and multiple
charging sources. The idea being to eliminate as many single points
of failure as possible, be able to cruise in the boondocks with
confidence, and to keep the boat going until we can reach a suitable
repair facility.

So far the strategy has paid off. In three years of ownership and
10,000 miles of cruising we have experienced two unscheduled shutdowns
of main engines and numerous generator issues, none of which were show
stoppers because of the backup systems on the boat.

wrote in message
...


I'm assuming that you will have a modern fin keel, broad beam, shallow
hull depth, type of boat with minimum skin friction. I did a really
quick calculation, assuming 20,000 lbs. displacement and came up with
45 shaft H.P., Shaft RPM of 1100 and a speed of about hull speed.
Sorry... I'm not into these calculations. Displacement is 22 to 24 ton
metric

Lastly, if you are like most owners of 60 ft. bespoken yachts you are
not in the first blush of youthfulness so either you have a crew or a
Sorry I still am at 39 ;-) No crew for me... expect for my wife and / or a
friend (or two)

So there you go. A sixty ft. mast and enough dacron to build a circus
Expect to be using a 24 to 26 meter mast.. so a little more. BUT still
conviced I will be motoring from time to time anf not only for harbouw
manoevres.

Cheers

Marc