Chris4943

Diesel Engine Delete

Recommended Posts

Would using a generator to power electric motor propulsion use up more diesel than just using a standard diesel engine for propulsion?

Share this post


Link to post
Share on other sites
3 minutes ago, Chris4943 said:

Would using a generator to power electric motor propulsion use up more diesel than just using a standard diesel engine for propulsion?

Yes.

  • Like 3

Share this post


Link to post
Share on other sites

Ok, thanks.  So, if I'm just starting to mentally design a go-anywhere self-sufficient cruiser, I should not forget to include a diesel engine for propulsion.  I was wrestling with the elegant solution of not needing one, but I guess sailboat cruisers probably do have them for a reason.  So now I need to think about house and engine battery banks, alternators, alternator regulators, battery combiners and isolators, etc.  Whew, ok.  

Share this post


Link to post
Share on other sites

If your goal is truly to be a "go-anywhere self-sufficient cruiser" then stick with the tried-and-true. If your goal is engineering, experimentation and repairing fussy crap in distant ports then by all means knock yourself out with the bleeding edge.

Plus, there is not much reliable wind in paradise, but rather long narrow channels, harbors in the lee, days of cloud cover, etc. Keep it basic. Depart sooner. Repair less.

If you want green systems install them ashore at your home, auto, business etc. where it really makes a difference.

That's my opinion.

  • Like 6

Share this post


Link to post
Share on other sites
2 minutes ago, El Boracho said:

If your goal is truly to be a "go-anywhere self-sufficient cruiser" then stick with the tried-and-true. If your goal is engineering, experimentation and repairing fussy crap in distant ports then by all means knock yourself out with the bleeding edge.

Plus, there is not much reliable wind in paradise, but rather long narrow channels, harbors in the lee, days of cloud cover, etc. Keep it basic. Depart sooner. Repair less.

If you want green systems install them ashore at your home, auto, business etc. where it really makes a difference.

That's my opinion.

Appreciated.  But the whole allure of deleting a diesel engine actually would be in the hope of cutting out unnecessary components so that I would be doing less repairing of fussy crap in distant ports.  No diesel engine = no repairing diesel engine components.  I already do need a generator, so I was wondering if that would be a reasonable power source for propulsion.  But if deleting the engine would mean diesel costs/storage/stops for the generator would be ridiculously multiplied, it might not be worth it. 

  • Like 1

Share this post


Link to post
Share on other sites

The chances a new-ish diesel engine will need repairs on a typical multi-year cruise is near zero. The generator should be as reliable except cruisers seem to have considerable trouble with generators and the related gear. Maybe it is the greater run hours?

It is sad that there are not popular ready solutions for generating large amounts of electricity from the propulsion engine. Flywheel and PTO alternators are rare.

  • Like 2

Share this post


Link to post
Share on other sites

It's the conversion losses from mechanical to electric and then back again.  A diesel generator powering an electric motor will have losses of up to 15%, whereas a direct diesel-mechanical installation will have losses half of that.

  • Like 5

Share this post


Link to post
Share on other sites
9 minutes ago, El Boracho said:

cruisers seem to have considerable trouble with generators and the related gear. 

I started watching an excellent youtube series from Pacific Yachting Systems on boat electrical, and his contention is that it's not the components that are failing, it's that hardly anybody knows how to properly wire anything, and even if they did, proper marine rated wiring is realllllly expensive, so a lot of boaters MacGuver complex components with cheap wiring and guess what: it fails all the time. 

So I'm trying to learn more about it so I don't go burn all my (future) stuff up.  To be fair, it's a heck of a steep learning curve so far. 

  • Like 2

Share this post


Link to post
Share on other sites

What is the horsepower of the standard diesel engine for your boat?

Share this post


Link to post
Share on other sites
1 minute ago, El Boracho said:

What is the horsepower of the standard diesel engine for your boat?

Sorry, so far all I've got is a pipe dream.  No boat yet.  I'm trying to think about what I would need and want and what components would work well for me, hence my question.  Thanks to ya'll answers, at least now I know I need a standard diesel engine!  Gotta start somewhere I guess. 

Share this post


Link to post
Share on other sites

Don’t fall for the trappings of the illusory perfect boat. Every boat is a compromise and the simpler it is the more actual redundancy you can maintain. 

 

  • Like 4

Share this post


Link to post
Share on other sites

no expert on comparing the 2 , but I always thought if I had to replace my diesel , volvo penta still runs great after 30 + years , of course yearly maintenance and repairs,

But any how having an electric motor to drive a sail boat , has alot of advantages, ask elon musk, electric motor has instant torque, unlike internal combustion, good for docking. Also there's many ways to keep the batteries topped off, solar, wind , even use the prop turning while sailing, and of course diesel or gas generators back up , which could also be used for heating /cooling the yacht , cooking with a electric stove and wife could even dry her hair! ( at anchor). And your don't have to worry about running out of dinosaur fuel. or have large tanks, Also todays batteries and electric motors have come a long way ie  Tesla

I once read ( years ago) a cat had electric driven props, so they set the up the boat for say 6kts motoring , then put up the sails, so the she start motoring , then motor sailing and then pure sailing while charging the batteries, At the end of the day they came back to the dock , batteries fully charged, 

So the best bet is do your home work , and If you race forget this !

  • Like 2

Share this post


Link to post
Share on other sites

Diesel electric is common in these applications:

1. Submarines. They use batteries underwater.

2. Tugboats. The electric motor can be easier to control and shift than a giant diesel and giant transmission. Remember they might go forward-reverse-forward more times in a day than you do in a month.

3. Cruise ships. They will have 2 or 4 electric motors and 4 to 6 (more??) gensets. The hotel loads on a cruise ship are huge, so it makes sense. Losing one diesel in mid-cruise is a non-event except for going a little slower.

4. Victory Ships (actually steam-electric). During WW II when they were built, the Navy had first call on reduction gears for turbines, so the Victory ships drove a generator with the steam turbine which powered an electric motor.

6. Railroad locomotives. The generator-electric motor combo takes the place of a clutch and transmission, which would never work with that much torque.

Where it is not common:

Yachts. Why add complexity to use more fuel and have a one-off high-tech system NO ONE in any port will have the faintest clue how to fix or support. Also note yachts are known to be WET and not have full time engineering staff.

BTW, a generator IS a diesel engine + electrical stuff. It isn't like it is more reliable than the same engine hooked to a tranny :rolleyes:

  • Like 5

Share this post


Link to post
Share on other sites
2 minutes ago, kent_island_sailor said:

Why add complexity to use more fuel and have a one-off high-tech system NO ONE in any port will have the faintest clue how to fix or support. Also note yachts are known to be WET and not have full time engineering staff.

BTW, a generator IS a diesel engine + electrical stuff. It isn't like it is more reliable than the same engine hooked to a tranny :rolleyes:

I wouldn't.  I didn't know it would use more fuel, so I asked that precise question.  Now that I know that the conversion from mechanical to electric to mechanical propulsion is way more inefficient than a diesel engine's mechanical propulsion, I'm sold. 

Since a generator IS a diesel engine, I had the thought that since I already know I'll have a generator, a diesel engine might be redundant.  Apparently it isn't, due to the conversion loss. 

Share this post


Link to post
Share on other sites
20 minutes ago, kent_island_sailor said:

Why add complexity

Also, I don't think anyone who brings up this point has seen an electric motor.  It's a metal tube with some copper windings and 2 wires.  It's infinitely less complex than a water cooled diesel engine with its own charging circuit (alternator, battery, etc) and which adds to the complexity of an electric system for the 'house' that may or may not need to work in conjunction with it.

Cutting out a diesel engine would reduce complexity.  The only rational reason to keep it (the factor that outweighs its complexity) would be if it's more efficient than an electric motor powered by a second diesel engine we already have onboard (the generator).

As you noted, electric motors on boats have been around since at least WWII, and are currently on tugs and cruise ships and all manner of seagoing vessels.  If you had to undo the 2 leads and bring in an electric motor to a far-off place, the locals would not go all The Gods Must Be Crazy and stone you to death for being a witch.  Electric motors are really common.  Even in boats.  (see your many examples)

  • Like 1

Share this post


Link to post
Share on other sites

Just buy diesel, its pre converted and compressed liquid sunshine, if youre into it you can even have a diesel stove and a diesel heater. Good stuff and it keeps the planet warm for cruising as an added benefit.

  • Like 4

Share this post


Link to post
Share on other sites
22 minutes ago, kent_island_sailor said:

Diesel electric is common in these applications:

 

3. Cruise ships. They will have 2 or 4 electric motors and 4 to 6 (more??) gensets. The hotel loads on a cruise ship are huge, so it makes sense. Losing one diesel in mid-cruise is a non-event except for going a little slower.

 

BTW, a generator IS a diesel engine + electrical stuff. It isn't like it is more reliable than the same engine hooked to a tranny :rolleyes:

Cruise ships have one more genset than the minimum, so one can be down for maintenance while the ship continues with no loss of performance. Also, their electrical loads vary a lot, so they bring on/drop off gensets as needed to support the loads & keep the gensets operating in their comfort zone.

  • Like 1

Share this post


Link to post
Share on other sites
2 minutes ago, toad said:

Just buy diesel, its pre converted and compressed liquid sunshine, if youre into it you can even have a diesel stove and a diesel heater. Good stuff and it keeps the planet warm for cruising as an added benefit.

This would be a recommendation for an electric motor then, as it takes more diesel to power it.

If anybody thinks I asked this cuz I'm a tree hugger, I'm not.  We're apparently not at a level yet where we can equal the efficiency of a diesel engine propulsion with electric.  So I'll go the actual tree hugger route and pick the more efficient diesel engine.  And another diesel engine that specializes in making electricity (for the 'house' electronics) ((a generator)).

Share this post


Link to post
Share on other sites

Generally you need an engine to motor about your cruising grounds but your boat does have sails and when the wind blows the boat goes....

I suspect youre pretty new to this game with a restricted budget, but just get a proven boat in good condition for your intended destinations, done bother reinventing the wheel. Generally the fringe dwellers- junk rigs, electric believers and ferro cruisers spend more time pontificating than doing. 

 

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Chris4943 said:

This would be a recommendation for an electric motor then, as it takes more diesel to power it.

If anybody thinks I asked this cuz I'm a tree hugger, I'm not.  We're apparently not at a level yet where we can equal the efficiency of a diesel engine propulsion with electric.  So I'll go the actual tree hugger route and pick the more efficient diesel engine.  And another diesel engine that specializes in making electricity (for the 'house' electronics) ((a generator)).

The vast majority of cruising sailboats do not have a generator. Unless you plan on having air conditioning, solar+alternator will do fine for you.

  • Like 3

Share this post


Link to post
Share on other sites

lol cruise ships are the worst examples to model after - they’re dirty, not environmentally friendly and the power generation is a priority because of all the annoying customers who want to basically live in a hotel staffed by Filipinos paid below the min wage. 

Unless you plan to have air independently propulsion like a diesel electric sub, why bother with expensive batteries. Just stop and keep the fanciful dream realistic. 

Pick a fast boat that can sail well even below 10 knots apparent - don’t carry shit you don’t need. Have a diesel and diesel tank for safety. Carry a few solar panels and hydrogen prop. 
 

done. 

  • Like 2

Share this post


Link to post
Share on other sites
17 minutes ago, Chris4943 said:

It's a metal tube with some copper windings and 2 wires.  It's infinitely less complex...

Maybe. 50 hp DC motors and generators are beasts. There are cooling fans. Temperature protection. Power switches. Field windings, their control circuits and perhaps another alternator. Brushes. Plus they are expensive, large and heavy. Tesla uses AC induction motors which are exceedingly complex to operate but it all works out in mass-production (I guess).

Add battery storage and the complexity will end pleasure cruising, guaranteed. Great engineering project though.

I would skip the second generator too, for sure, but that is just the way I roll. 

At some point in a thread like this some moonbeam will assert that an electric motor only needs to be 8 hp to replace a huge diesel engine. They always do....

  • Like 2

Share this post


Link to post
Share on other sites
2 minutes ago, Chris4943 said:

This would be a recommendation for an electric motor then, as it takes more diesel to power it.

If anybody thinks I asked this cuz I'm a tree hugger, I'm not.  We're apparently not at a level yet where we can equal the efficiency of a diesel engine propulsion with electric.  So I'll go the actual tree hugger route and pick the more efficient diesel engine.  And another diesel engine that specializes in making electricity (for the 'house' electronics) ((a generator)).

Diesel is good, you wont  regret it.

  • Like 1

Share this post


Link to post
Share on other sites
2 minutes ago, El Boracho said:

Maybe. 50 hp DC motors and generators are beasts. There are cooling fans. Temperature protection. Power switches. Field windings, their control circuits and perhaps another alternator. Brushes. Plus they are expensive, large and heavy. Tesla uses AC induction motors which are exceedingly complex to operate but it all works out in mass-production (I guess).

Add battery storage and the complexity will end pleasure cruising, guaranteed. Great engineering project though.

I would skip the second generator too, for sure, but that is just the way I roll. 

At some point in a thread like this some moonbeam will assert that an electric motor only needs to be 8 hp to replace a huge diesel engine. They always do....

I like to point out a 5 gallon  jug of fuel weighs 30 pounds and will take me 20-60 miles or so, depending on the weather. How far will a 30 pound battery take you - across the marina?

  • Like 2

Share this post


Link to post
Share on other sites

On and by the way you only need 2hp per ton to push your ship along and if electric you only need the engine out of your watch...

Share this post


Link to post
Share on other sites
4 minutes ago, toad said:

I suspect youre pretty new to this game with a restricted budget, but just get a proven boat in good condition for your intended destinations, done bother reinventing the wheel. Generally the fringe dwellers- junk rigs, electric believers and ferro cruisers spend more time pontificating than doing. 

 

You don't have to suspect, further up in the thread I noted that I don't even have a boat yet.  That gives me the freedom to think about what I will need.  Thanks to ya'lls advice, I now know I'll need a diesel engine.

I'm sorry you have to endure moon brained tree hugging electric zealots who think they can replace everything on a boat, but that's not me.

Share this post


Link to post
Share on other sites
1 minute ago, toad said:
4 minutes ago, Chris4943 said:

This would be a recommendation for an electric motor then, as it takes more diesel to power it.

If anybody thinks I asked this cuz I'm a tree hugger, I'm not.  We're apparently not at a level yet where we can equal the efficiency of a diesel engine propulsion with electric.  So I'll go the actual tree hugger route and pick the more efficient diesel engine.  And another diesel engine that specializes in making electricity (for the 'house' electronics) ((a generator)).

Diesel is good, you wont  regret it.

As of now, there is no battery that can store energy at the same density as diesel fuel. Therefore, carrying diesel fuel gives you more energy to use for devoting any given amount of cubic & weight. A corollary to this is that solar panels can provide electricity in the same way sails can provide propulsion... at unreliable intervals in modest quantity.

Propulsion is the biggest power load, it makes the most sense to size a diesel engine to propel the boat and use that same diesel engine to generate large amounts of electricity when needed (charging batteries quickly while also powering house loads).

Technology is advancing, already refrigeration has become more efficient and solar panels can support it, lighting has become almost free in terms of electrical demand. I expect this trend to continue but as of now, there is no rational reason to go to a "new" or unconventional configuration for your boat's power.

FB- Doug

  • Like 2

Share this post


Link to post
Share on other sites
23 minutes ago, Chris4943 said:

Also, I don't think anyone who brings up this point has seen an electric motor.  It's a metal tube with some copper windings and 2 wires.  It's infinitely less complex than a water cooled diesel engine with its own charging circuit (alternator, battery, etc) and which adds to the complexity of an electric system for the 'house' that may or may not need to work in conjunction with it.

Cutting out a diesel engine would reduce complexity.  The only rational reason to keep it (the factor that outweighs its complexity) would be if it's more efficient than an electric motor powered by a second diesel engine we already have onboard (the generator).

As you noted, electric motors on boats have been around since at least WWII, and are currently on tugs and cruise ships and all manner of seagoing vessels.  If you had to undo the 2 leads and bring in an electric motor to a far-off place, the locals would not go all The Gods Must Be Crazy and stone you to death for being a witch.  Electric motors are really common.  Even in boats.  (see your many examples)

No - electric motors are not a common way to move sailing yachts at all. Do yourself a favor and make the following decision:

1. I love engineering and want to make a new invention . I will have a lot of fun making an expensive one-off propulsion system and working out the many problems that come up. Meters and oscilloscopes are my passion. High voltage and wet bilges sounds exciting :D

2. I want to go someplace in a sailboat that is reasonably reliable and fixable by normal humans in distant ports B)

And for the love of King Neptune PLEASE ignore the occasional electric boat proselytizer. They always start off with outlandish claims and when pressed, admit they can't do X, Y, or Z but then decide they did not want to do any of that anyway :rolleyes:

  • Like 4

Share this post


Link to post
Share on other sites
7 minutes ago, Miffy said:

why bother with expensive batteries. Just stop and keep the fanciful dream realistic.

Because I realistically want to move into a boat and use it as a home.  I could rough it like survivor-man and drink my own urine I guess, but I don't think going super extreme is very realistic.  Solar has gotten to a level where I can actually use it to power a lot of creature comforts that would make such a life style change more realistic.  I was wondering if electric motors were a good way to go after seeing a few cruisers with them, but apparently not.  Solar definitely can't keep up with them, I knew that much.  Not even close.  Batteries can't either.  That left a generator, which I don't know much about.

Share this post


Link to post
Share on other sites

You seem to lack even the basic rudiments of knowledge about your newfound passion. No problem - so did I and everyone else at some point.

Lets cut to the chase - where are you trying to go and how much cash do you have to spend?

Share this post


Link to post
Share on other sites
11 minutes ago, kent_island_sailor said:

I like to point out a 5 gallon  jug of fuel weighs 30 pounds and will take me 20-60 miles or so, depending on the weather. How far will a 30 pound battery take you - across the marina?

Yeah a battery can't come close to storing the kind of energy needed to run a motor.  Since a generator can, I was wondering if that was a viable option.  

So, yeah.  Batteries can't.  Got it. 

But how about a generator?

Apparently also can't cut it, due to conversion.

If you read posts on forums you'd be up to speed on where this discussion is.  This was settled a while up. 

Share this post


Link to post
Share on other sites
4 minutes ago, kent_island_sailor said:

You seem to lack even the basic rudiments of knowledge about your newfound passion.

About my potential passion.  Which is why I asked the question.  Which was well answered already. 

You seem to not read this thread.

No problem, I just don't think this is a 2 way communication.  Go off. 

Share this post


Link to post
Share on other sites

Personally I think the next frontier is ocean battery powered electric drive. 

you build an aluminum boat. Stick some dissimilar mental a thru the hull. Connect it with wires and hook it up to a DC electric motor. It’ll be amazing - but you need to believe. 

  • Like 1

Share this post


Link to post
Share on other sites

you will be able to fix a mechanical diesel on board in the middle of nowhere but you wont be able to fix an electric drive train

Share this post


Link to post
Share on other sites

There is a ton of interesting stuff happening in power storage tech, from improved battery technology to graphene supercapacitors that you can print with your DVD writer (if you still have one).
 

Now seems to be a particularly bad time to get into electrical power unless you specifically want to experiment with bleeding edge tech. I'm a software engineer, and I can assure you that you want as little bleeding edge tech on your boat as possible, particularly if it has any software in it. Go with the cheapest conventional solution you can and watch what develops with electric power. 

 

Share this post


Link to post
Share on other sites
27 minutes ago, Miffy said:

Personally I think the next frontier is ocean battery powered electric drive. 

you build an aluminum boat. Stick some dissimilar mental a thru the hull. Connect it with wires and hook it up to a DC electric motor. It’ll be amazing - but you need to believe. 

Yep, good solution.  And, if you run low on hull during that 12 hour thrash off a lee shore, you can always use your inbuilt back up system - amalgam filling/silver foil/saliva.  It's a bastard getting the alligator clips in there though.

image.png.ca664438ed957b286287f416ad74d65c.png

  • Like 1

Share this post


Link to post
Share on other sites

one bonus with a el motor on a sail boat is when sailing you can make power to charge batterys

if you are willing to lose a bit of speed for free power the catch is battery cost/weight/space

Share this post


Link to post
Share on other sites
5 hours ago, nota said:

one bonus with a el motor on a sail boat is when sailing you can make power to charge batterys

if you are willing to lose a bit of speed for free power the catch is battery cost/weight/space

In catamaran you could replace two diesels with one. There seems to be options for that, but they are quite new, so you'll likely pay for it. Probably both in money and teething problems. And lack or redundancy that seems to be one selling point for catamarans, when considering cruising boats.

Share this post


Link to post
Share on other sites

As someone who designs tugs for a living, diesel-electric tugs are very rare! 

  • Like 1

Share this post


Link to post
Share on other sites
24 minutes ago, Zonker said:

As someone who designs tugs for a living, diesel-electric tugs are very rare! 

Yeah I had you pegged as a tugger 

  • Like 1

Share this post


Link to post
Share on other sites

Well last week it was consulting on a 30' fisheries research catamaran and I used to design sailboats. Done ferries, fireboats, barges, fast power yachts, small tankers, etc etc. About the only thing I haven't designed is fishing boats. 

Share this post


Link to post
Share on other sites

Fishing boats- piece of piss.. all you need is beer holders and somewhere to stick them big ol' bad boys on the tuck

 

yysw192807.jpg

Share this post


Link to post
Share on other sites

I am not so sure your question is as outlandish as everyone is making it out to be. I believe it is a question of use. If you want to be able to strike off in any weather and motor all day then battery electric just doesn't have the range and having sufficient solar to give you that range is not practical currently due to the area required for panels. If you just need to motor out of the marina and back and then plug her into shore power you might flourish with electric, and it sure is a lot easier at some times like putting her away for the winter! I also think it depends on the displacement and size of the boat. Smaller more easily moved boats make the equation more sensible but bug tubby cruisers start to run out of battery capacity sooner and batteries are expensive in money, space, and weight. 

Augmenting your batteries with a generator seems a great solution to me for the times you need more range, but finding real data on how much power you are going to need and how you are going to set it up is not an easy thing to find. In my case I am plugging the generator into the battery charger but then you have the limits of the charger and undoubtedly some extra losses of efficiency. 

Keep thinking and working on it, I believe solutions like this will evolve into great solutions for all of us! 

Share this post


Link to post
Share on other sites
2 hours ago, Zonker said:

As someone who designs tugs for a living, diesel-electric tugs are very rare! 

agreed, too expensive

speaking of electric tugs have you seen the new integrated electric Voith Schneider drive, very cool

 

Here's the first electric tug

https://www.maritime-executive.com/article/ports-of-auckland-buys-world-first-electric-tug

PS not quite true as ABB fitted out one in Europe as an experiment, it was a project to reduce pollution and fuel consumption which it did but with batteries and 6 gen sets must have cost lots...

Share this post


Link to post
Share on other sites

Apparently you can make a reasonable battery by sticking a bit of copper up your ass and an aluminum beer can in your hand, about 1.4 volts but the amps are pretty weak, but if you got a whole lot of cheerleaders to batteryfy themselves on the above fishing boat and connected them all up in series you could get some sparks going

Share this post


Link to post
Share on other sites
11 hours ago, kent_island_sailor said:

Diesel electric is common in these applications:

1. Submarines. They use batteries underwater.

2. Tugboats. The electric motor can be easier to control and shift than a giant diesel and giant transmission. Remember they might go forward-reverse-forward more times in a day than you do in a month.

3. Cruise ships. They will have 2 or 4 electric motors and 4 to 6 (more??) gensets. The hotel loads on a cruise ship are huge, so it makes sense. Losing one diesel in mid-cruise is a non-event except for going a little slower.

4. Victory Ships (actually steam-electric). During WW II when they were built, the Navy had first call on reduction gears for turbines, so the Victory ships drove a generator with the steam turbine which powered an electric motor.

6. Railroad locomotives. The generator-electric motor combo takes the place of a clutch and transmission, which would never work with that much torque.

Where it is not common:

Yachts. Why add complexity to use more fuel and have a one-off high-tech system NO ONE in any port will have the faintest clue how to fix or support. Also note yachts are known to be WET and not have full time engineering staff.

BTW, a generator IS a diesel engine + electrical stuff. It isn't like it is more reliable than the same engine hooked to a tranny :rolleyes:

Kent,

Partially correct on #4. Liberty ships were steam reciprocating for your transmission point but also for mass production as well.  Victory ships which came in 1944/45 were steam turbine direct, no electric motor drive.

Share this post


Link to post
Share on other sites
3 hours ago, Zonker said:

As someone who designs tugs for a living, diesel-electric tugs are very rare! 

I actually looked at one for sale. She ran fine, but the interior was nasty and you could see sunlight through rust holes in the superstructure. She had been a "railroad tug" before retiring to pleasure-tugging :D

My wife, ever the practical one, pointed out the interior looked like a dumpster and the boat wouldn't fit in our slip :(

Share this post


Link to post
Share on other sites
48 minutes ago, sailman said:

Kent,

Partially correct on #4. Liberty ships were steam reciprocating for your transmission point but also for mass production as well.  Victory ships which came in 1944/45 were steam turbine direct, no electric motor drive.

 I think you are wrong on that. Direct drive turbines are hugely inefficient and I have read a couple stories of merchant mariners dealing with Victory Ship electric drive systems shorting out due to wetness and old age. Hang on a sec - a little Google-Fu shows Victory ships got made with all kinds of engines, probably whatever was around that day. Some were diesel, some were reciprocating steam, some were turbines, most were oil fired, and some were even coal fired. Probably some electric drives made it in there too. It all seemed based on various materials shortages.

Share this post


Link to post
Share on other sites

See Sailing Uma youtube channel.  Dan is obviously a much more capable technician than most, but they've done 20k+ miles, crossed the pond, and never had a diesel, only an old electric forklift motor.  They have nice lithium batteries now, but started with lead acids.  They never even had regen until very recently when they updated to an oceanvolt saildrive, and only 400 watts of solar.  No genset.  They do have a nice dinghy with 15hp outboard, so they aren't total tree-huggers.

They are 'real' sailors, and actually sail their boat, and they are patient people, much different than most modern 'get me there now' sailors.

However, they are proof it can be done, and done with very reasonable comfort.

  • Like 2

Share this post


Link to post
Share on other sites
13 hours ago, Chris4943 said:

Appreciated.  But the whole allure of deleting a diesel engine actually would be in the hope of cutting out unnecessary components so that I would be doing less repairing of fussy crap in distant ports.  No diesel engine = no repairing diesel engine components.  I already do need a generator, so I was wondering if that would be a reasonable power source for propulsion.  But if deleting the engine would mean diesel costs/storage/stops for the generator would be ridiculously multiplied, it might not be worth it. 

Why do you need a generator? Most long distance cruisers don't have one. We had a 5 kW genset on our boat and rarely used it. We had a high output alternator on the engine, solar and wind for supply. Used our Monitor for steering way more often than our CPT autopilot. I think you should start from the demand end of things and work back to supply.

  • Like 2

Share this post


Link to post
Share on other sites
26 minutes ago, kent_island_sailor said:

I actually looked at one for sale. She ran fine, but the interior was nasty and you could see sunlight through rust holes in the superstructure. She had been a "railroad tug" before retiring to pleasure-tugging :D

My wife, ever the practical one, pointed out the interior looked like a dumpster and the boat wouldn't fit in our slip :(

Wives can bel like that. I am trying to convince my wife we need two boats, one on Lake Ontario for the summer and one in the Caribbean for the winter, not going well.

Share this post


Link to post
Share on other sites
7 minutes ago, Bristol-Cruiser said:

Wives can bel like that. I am trying to convince my wife we need two boats, one on Lake Ontario for the summer and one in the Caribbean for the winter, not going well.

The thought of refilling 10,000 gallon fuel tanks and marina fees of $3/foot X 120 feet was also a bit intimidating.

Share this post


Link to post
Share on other sites
11 minutes ago, nlmasopust said:

See Sailing Uma youtube channel.  Dan is obviously a much more capable technician than most, but they've done 20k+ miles, crossed the pond, and never had a diesel, only an old electric forklift motor.  They have nice lithium batteries now, but started with lead acids.  They never even had regen until very recently when they updated to an oceanvolt saildrive, and only 400 watts of solar.  No genset.  They do have a nice dinghy with 15hp outboard, so they aren't total tree-huggers.

They are 'real' sailors, and actually sail their boat, and they are patient people, much different than most modern 'get me there now' sailors.

However, they are proof it can be done, and done with very reasonable comfort.

I have sailed my boat with no engine at all when the engine was down for repairs and I really wanted to go out. Back in the day plenty of boats got all around the world with no engines, so obviously it is possible. It is also a huge PITA unless one has infinite patience and no job to get back to.

Share this post


Link to post
Share on other sites
13 minutes ago, kent_island_sailor said:

I have sailed my boat with no engine at all when the engine was down for repairs and I really wanted to go out. Back in the day plenty of boats got all around the world with no engines, so obviously it is possible. It is also a huge PITA unless one has infinite patience and no job to get back to.

Fortunately for them there is Patreon and nice sponsorships in the marine industry!  :)

Share this post


Link to post
Share on other sites
18 minutes ago, kent_island_sailor said:

I have sailed my boat with no engine at all when the engine was down for repairs and I really wanted to go out. Back in the day plenty of boats got all around the world with no engines, so obviously it is possible. It is also a huge PITA unless one has infinite patience and no job to get back to.

There are still a few boats engineless today. We crossed paths in the Pacific a few times with a young guy in Bristol 27 without an engine. He was seeing the same things as the guys with the 100 footers except you never see the hundred footers in remote spots. They are too busy getting the money to buy the 160 footer.

My point was not that one doesn't need an engine but that one does not need a generator. Basic diesel mechanics - changing filters, bleeding the fuel system, taking off the alternator or starter to go visit a shop thats or of thing is not hard. After all I learned how to do it. I said to my wife, here we are six university degrees between us and nary a course in Diesel engines. I said it was her fault since she has a doctorate in engineering physics, surely diesels came up at some point, but no. My degrees were in geography and education so you could imagine nothing about engines there.

 

Share this post


Link to post
Share on other sites

What about Hydrogen cell power?

My company is currently building a 365M containership powered with it.

Hat / Door..

Sail Safe!

Share this post


Link to post
Share on other sites
51 minutes ago, kent_island_sailor said:

 I think you are wrong on that. Direct drive turbines are hugely inefficient and I have read a couple stories of merchant mariners dealing with Victory Ship electric drive systems shorting out due to wetness and old age. Hang on a sec - a little Google-Fu shows Victory ships got made with all kinds of engines, probably whatever was around that day. Some were diesel, some were reciprocating steam, some were turbines, most were oil fired, and some were even coal fired. Probably some electric drives made it in there too. It all seemed based on various materials shortages.

I worked on some T-4 (the oil tanker equivalent) and some Victories when I first got out of the Navy. They were built quick with whatever was at hand, I recall the turbo-electric engine rooms. The turbogenerators were a mixed bag. The drive motor was probably 40 or 50 feet in diameter, not something you could replicate on a small sailboat scale unless you wanted to live your life crawling around & over the engine. The boilers were pretty standard 600lb M-types, I mostly worked on getting those tight & fire-worthy again, and the forced draft blowers & the regulating systems for all.

Steam power is simple but it's also HOT and dirty. Heavy per HP, too, which is why there have been rather few steam-powered aircraft in history. Diesels are much much better!

FB- Doug

Share this post


Link to post
Share on other sites
1 hour ago, kent_island_sailor said:

 I think you are wrong on that. Direct drive turbines are hugely inefficient and I have read a couple stories of merchant mariners dealing with Victory Ship electric drive systems shorting out due to wetness and old age. Hang on a sec - a little Google-Fu shows Victory ships got made with all kinds of engines, probably whatever was around that day. Some were diesel, some were reciprocating steam, some were turbines, most were oil fired, and some were even coal fired. Probably some electric drives made it in there too. It all seemed based on various materials shortages.

Direct Drive was not a correct term, they were Steam Turbine through double reduction gears.  I sailed on one.  It was a 600# plant with steam turbine DC generators, all the motors on the ship were DC there were motor-generator sets for AC power.  The Wiki entries about multiple engines were based on design spec, I think, there was one diesel powered Victory, no steam reciprocating engines.

Share this post


Link to post
Share on other sites
33 minutes ago, Bristol-Cruiser said:

My point was not that one doesn't need an engine but that one does not need a generator.

Unless the engine is electric and you want extend the motoring range from few miles to day or longer.

Share this post


Link to post
Share on other sites

So we have one person that actually worked on a reduction-gear turbine Victory ship and another one that actually worked on a turbine-electric Victory ship. This place is great :D

  • Like 2

Share this post


Link to post
Share on other sites
1 hour ago, SailRacer said:

What about Hydrogen cell power?

My company is currently building a 365M containership powered with it.

Hat / Door..

Sail Safe!

how are they making the hydrogen?

Gas or liquid storage?

What type of engine?

Share this post


Link to post
Share on other sites

Err.. it is on a need to know basis for me and I am a deck officer ashore and do not need to know.

Google may be your friend and reveal more than I know.

Sail safe!

Share this post


Link to post
Share on other sites
15 hours ago, kent_island_sailor said:

2. Tugboats. The electric motor can be easier to control and shift than a giant diesel and giant transmission. Remember they might go forward-reverse-forward more times in a day than you do in a month.

 

The tugs that are doing the kind of towing that requires what you describe, i.e. harbour and river tugs, will nearly all be using Azimuth, Voith Schneider or some other form of thruster.
Certainly the only old school tugs with normal drives and gearboxes we see around here are all decades old, certainly not diesel electric.

Share this post


Link to post
Share on other sites
10 minutes ago, MiddayGun said:

The tugs that are doing the kind of towing that requires what you describe, i.e. harbour and river tugs, will nearly all be using Azimuth, Voith Schneider or some other form of thruster.
Certainly the only old school tugs with normal drives and gearboxes we see around here are all decades old, certainly not diesel electric.

The diesel-electric tug for sale that we looked at was not close to new, so it may well be no one does it that way anymore. The tug was built for a railroad that had barges too, maybe for railroad cars to move across a river, so perhaps the railroad people were used to diesel-electric and wanted more of the same. The engine room was full of scary looking frankenstein switches, not a place for bare feet :o

The first one was built in 1930: https://en.wikipedia.org/wiki/Luna_(tugboat)

The one we looked at came from New York and was built in the 50s IIRC.

Share this post


Link to post
Share on other sites
19 minutes ago, kent_island_sailor said:

The diesel-electric tug for sale that we looked at was not close to new, so it may well be no one does it that way anymore. The tug was built for a railroad that had barges too, maybe for railroad cars to move across a river, so perhaps the railroad people were used to diesel-electric and wanted more of the same. The engine room was full of scary looking frankenstein switches, not a place for bare feet :o

The first one was built in 1930: https://en.wikipedia.org/wiki/Luna_(tugboat)

The one we looked at came from New York and was built in the 50s IIRC.

Hmm I stand corrected. She's a good looker as well.
I guess they never really took off, though I suppose in the low carbon future they will all be electric drive.

Honestly once you've been on a real ASD tug, its hard to imagine going back to the old twin screw business.

Share this post


Link to post
Share on other sites

Sailing Uma has 12 x 100 A.hr li-ion batteries. About $12k at retail pricing. I can buy a nice diesel for that price. And that does not include an electric motor, controller or cabling. 

1200 A. Hr of battery is ~10 KW.hr of capacity. So I can motor at 5 KW (7 hp) for 2 hours until the battery is dead. If very limited range is ok with you and you're a "real sailor" then sounds great. 

I'm their test video they say they can motor at 6.5 knots for 1 hour then thd battery is dead. Obviously if they motor at 3 knots they can probably motor for 6 hours or more. 

 

Share this post


Link to post
Share on other sites
9 minutes ago, Zonker said:

Sailing Uma has 12 x 100 A.hr li-ion batteries. About $12k at retail pricing. I can buy a nice diesel for that price. And that does not include an electric motor, controller or cabling. 

1200 A. Hr of battery is ~10 KW.hr of capacity. So I can motor at 5 KW (7 hp) for 2 hours until the battery is dead. If very limited range is ok with you and you're a "real sailor" then sounds great. 

I'm their test video they say they can motor at 6.5 knots for 1 hour then thd battery is dead. Obviously if they motor at 3 knots they can probably motor for 6 hours or more. 

 

The challenges for electric car and boats are basically the same. Battery cost quickly escalates and any weight and efficiency benefits from high voltage motors. And as you increase range? The environmental benefits quickly start looking less attractive. (E.g. commute golf cart with 50km range vs 400km range vehicle that weighs 3 tons). 
 

And to me, the ultimate pin that pops the fanciful notion is if I’m demasted - with 60 liters, 2 liters per hr and 5 knots? I can motor 150 nm. 

The expensive electric system? If fully charged? 30nm if you go along at 3 knots with no current or sea way. 

For what gain? I don’t get it. Batteries aren’t free and producing them has environmental costs too. 

  • Like 1

Share this post


Link to post
Share on other sites
29 minutes ago, MiddayGun said:

Hmm I stand corrected. She's a good looker as well.
I guess they never really took off, though I suppose in the low carbon future they will all be electric drive.

Honestly once you've been on a real ASD tug, its hard to imagine going back to the old twin screw business.

Diesel-Electric seems poised to make a comeback with the addition of batteries for a hybrid type drive and even straight battery tugs that recharge off shore power now seem to be a thing if the google results are to be believed. Not sure about twin screw business, the old girl we looked at had exactly one screw and no bow thruster. so that would be REAL old time ship handling.

 

Share this post


Link to post
Share on other sites
14 minutes ago, Miffy said:

The challenges for electric car and boats are basically the same. Battery cost quickly escalates and any weight and efficiency benefits from high voltage motors. And as you increase range? The environmental benefits quickly start looking less attractive. (E.g. commute golf cart with 50km range vs 400km range vehicle that weighs 3 tons). 
 

And to me, the ultimate pin that pops the fanciful notion is if I’m demasted - with 60 liters, 2 liters per hr and 5 knots? I can motor 150 nm. 

The expensive electric system? If fully charged? 30nm if you go along at 3 knots with no current or sea way. 

For what gain? I don’t get it. Batteries aren’t free and producing them has environmental costs too. 

You beat me to it. With cars you can plan a trip with recharging stations, with a boat? Nope. The offshore racing I do has your last paragraph as a requirement - relying on others to bail you out is stupid and selfish.  Always have a Plan B.

  • Like 1

Share this post


Link to post
Share on other sites
Just now, d'ranger said:

You beat me to it. With cars you can plan a trip with recharging stations, with a boat? Nope. The offshore racing I do has your last paragraph as a requirement - relying on others to bail you out is stupid and selfish.  Always have a Plan B.

And at sea, if you’re diverted, you can get more diesel. Seafarers will kindly float you five 20 liter jerrycans. 

If you run electric only - abandon the lithium ship to the ocean? 

Commercial shipping is all about operating cost and mission parameters - an azimuth pod driven ship with specific electric needs, or power system redundancy design may decouple mechanical linkages. Submarines naturally want air independent propulsion. Locomotives benefit from the torque at low rpm to get going and emission management. 
 

Sailboats? The only use case I can think of that’s rational would be club boats/day sailors that have a small battery for getting in and out from the dock.

For live aboard/ocean sailing? If you have air conditioning, electric cooking, lots of watermaking - luxurious cruising, then you’ll be running a high load genset & possibly supplementing that with a large solar array. Then maybe series hybrid electric drive would make more sense. But it won’t be environmental- it is just opulence. 

  • Like 1

Share this post


Link to post
Share on other sites
40 minutes ago, Zonker said:

Sailing Uma has 12 x 100 A.hr li-ion batteries. About $12k at retail pricing. I can buy a nice diesel for that price. And that does not include an electric motor, controller or cabling. 

1200 A. Hr of battery is ~10 KW.hr of capacity. So I can motor at 5 KW (7 hp) for 2 hours until the battery is dead. If very limited range is ok with you and you're a "real sailor" then sounds great. 

I'm their test video they say they can motor at 6.5 knots for 1 hour then thd battery is dead. Obviously if they motor at 3 knots they can probably motor for 6 hours or more. 

 

IME Diesel engines are unreliable, noisy and smelly. So for numpties like me who feel more at ease with a voltmeter than a filter wrench, the trade off isn't as bad as you make it sound.

PS : I am procrastinating on the internet instead of sailing due to a diesel maintenance that was delayed by COVID!

Share this post


Link to post
Share on other sites
1 minute ago, Miffy said:

Sailboats? The only use case I can think of that’s rational would be club boats/day sailors that have a small battery for getting in and out from the dock.

 

Here a yacht club now has a dozen RS21s.  Already obvious when doing a bay race they don't have the capacity to return if the wind quits or things go pear shaped. For getting to/from the RC? Perfect (as long as you can also sail).  Whether we like it or not fossil fuels rule. I surrendered for a battery weedwhacker that requires stupid expensive batteries (because they give you free spools) as it makes SWMBO happy.  All heavy equipment will run all day on a tank of diesel, ten minutes to refuel.  Electric has applications that make sense, in boats that is very limited.

Share this post


Link to post
Share on other sites

Back to the original problem, which as I interpret it was, how to get away from having both a diesel engine for propulsion and a diesel driven generator...

Having established that a D-E drive system does not make sense, you are better off trying to figure out how to ditch the dedicated generator engine.

So, look at better solutions for alternators on the main engine, and alternative power generation sources, along with better battery solutions.

  • Like 1

Share this post


Link to post
Share on other sites
27 minutes ago, Panoramix said:

IME Diesel engines are unreliable, noisy and smelly. So for numpties like me who feel more at ease with a voltmeter than a filter wrench, the trade off isn't as bad as you make it sound.

PS : I am procrastinating on the internet instead of sailing due to a diesel maintenance that was delayed by COVID!

You must have the wrong engines. The trade-off is about a 98% reduction in range to save learning how to change filters :P

  • Like 1

Share this post


Link to post
Share on other sites
18 hours ago, El Boracho said:

If your goal is truly to be a "go-anywhere self-sufficient cruiser" then stick with the tried-and-true. If your goal is engineering, experimentation and repairing fussy crap in distant ports then by all means knock yourself out with the bleeding edge.

Plus, there is not much reliable wind in paradise, but rather long narrow channels, harbors in the lee, days of cloud cover, etc. Keep it basic. Depart sooner. Repair less.

If you want green systems install them ashore at your home, auto, business etc. where it really makes a difference.

That's my opinion.

a voice of experience :)

trouble is ya giving it away for free so nobodys gunna listen 

now if ya was charging 100 / hr be a different thing ....

  • Like 1

Share this post


Link to post
Share on other sites
8 minutes ago, Expat Canuck said:

Back to the original problem, which as I interpret it was, how to get away from having both a diesel engine for propulsion and a diesel driven generator...

Having established that a D-E drive system does not make sense, you are better off trying to figure out how to ditch the dedicated generator engine.

So, look at better solutions for alternators on the main engine, and alternative power generation sources, along with better battery solutions.

I can make many scenarios for D-E drive. Imagine a big cat with two diesels and one genset, so she had 3 engines to maintain. Replace that with 2 electric engines and 2 gensets. We all know that diesels do not like a light load, so if you want to motor at 6 or 7 knots on a calm day, use one genset to power both electric motors and run hotel loads. One engine at 75% output beats two at 37.5% output :) You also have redundancy, one diesel offline still leaves you with electricity and power for both electric motors, just not as much.

This scheme falls apart in two ways: One is unlike a ship, this is not a check the box option, you are pioneering/inventing as you go along. Expense is liable to be high and reliability low because you have the only one of these specific combinations of parts in the entire world. The other way it blows up is when people get the idea to add a big battery bank and regen motor/generators and probably solar on top of all that. Now you get a horrendous level of complication that needs full time support staff. IIRC, some charter company tried it and could not keep the boats running.

 

Share this post


Link to post
Share on other sites

Okay, I should have said: " Having established that a D-E drive system does not make sense for the OP"

Perhaps, if you have a large cat, and are looking to replace a suite of 4 engines (2 propulsion and 2 gensets), you can start to look at some thing like you propose.  BUT, a diesel-mechanical drive engine even at low power is generally still more efficient than a diesel-electric (at least that is what we have found at work).  I know it's surprising and counter to what you would think, but the numbers don't lie.

As you say, for your scenario, you are looking at added complexity (and cost).

I work with Zonker, and as far as I know, we have yet to do a Diesel-Electric or Diesel-Electric-Hybrid (i.e. with battery) tug project that is 100% commercially funded (without some sort of government support) except perhaps something with very weird extenuating circumstances .  Certainly none of my projects have been.

Edited by Expat Canuck
clarity

Share this post


Link to post
Share on other sites
20 minutes ago, kent_island_sailor said:

Expense is liable to be high and reliability low

A custom D-E system on a cat is an ideal project for the person who loves spending money moving engineers, one-off parts and broken boats from place to place. Of course, doing the prototyping at full scale on an expensive yacht adds style points.

Share this post


Link to post
Share on other sites
40 minutes ago, kent_island_sailor said:

You must have the wrong engines. The trade-off is about a 98% reduction in range to save learning how to change filters :P

The issue is not filters or the engine itself but all the ancillaries that don't seem to be designed to marine specs : cooling system issues (pump, crap that gets in there), condensation in the tank, air in the fuel line, diesel that goes bad / crap in the tank, injector issues, belt tension...

Typically this just happens after a rough passage when you need it the least.

Share this post


Link to post
Share on other sites
9 minutes ago, Expat Canuck said:

Okay, I should have said: " Having established that a D-E drive system does not make sense for the OP"

Perhaps, if you have a large cat, and are looking to replace a suite of 4 engines (2 propulsion and 2 gensets), you can start to look at some thing like you propose.  BUT, a diesel-mechanical drive engine even at low power is generally still more efficient than a diesel-electric (at least that is what we have found at work).  I know it's surprising and counter to what you would think, but the numbers don't lie.

As you say, for your scenario, you are looking at added complexity (and cost).

I work with Zonker, and as far as I know, we have yet to do a Diesel-Electric or Diesel-Electric-Hybrid (i.e. with battery) project that is 100% commercially funded (without some sort of government support).  Certainly none of my projects have been.

Yah to find the “use case” that makes it sensible, you invariably end up looking at a modern DDG with an aesa radar array that pumps out enough energy to control airspace 300nm in diameter. 

And provide electric power for hundreds of crew, support services, battle control systems. 

It doesn’t require a lot of conservation of energy/mass understanding to see how diesel to kinetic, kninetic to electric, electric back to chemical, chemical back to electric, back to kinetic is... a strange idea for energy conservation. 

Share this post


Link to post
Share on other sites

The best energy conservation is a light boat and big sails ;) My cat example was an attempt to make a use-case that sort of made sense if you like to be a mad scientist.

 

Share this post


Link to post
Share on other sites
18 hours ago, El Boracho said:

Maybe. 50 hp DC motors and generators are beasts. There are cooling fans. Temperature protection. Power switches. Field windings, their control circuits and perhaps another alternator. Brushes. Plus they are expensive, large and heavy. Tesla uses AC induction motors which are exceedingly complex to operate but it all works out in mass-production (I guess).

Add battery storage and the complexity will end pleasure cruising, guaranteed. Great engineering project though.

I would skip the second generator too, for sure, but that is just the way I roll. 

At some point in a thread like this some moonbeam will assert that an electric motor only needs to be 8 hp to replace a huge diesel engine. They always do....

I lived with DC motors and brushed ac devices in a marine environment for many years. Horrible. Diesel Electric only survives because it is a very flexible propulsion system at scale providing gobs of torque and maneuverability. 3 phase AC motors are pretty simple and pretty efficient devices... shaft 2 bearings and some copper. It's the controls and various devices needed to convert the DC back to 3 phase AC that are the complex fussy, inefficient bits. Of course these fussy electronics do really well in a marine environment. Diesel has the one of the highest energy densities,  its a reliable, proven technology in a marine environment, parts and repairs available just about anywhere on the planet. (maybe not oem but someone will know how to fix a diesel) whats not to like?

 

Share this post


Link to post
Share on other sites