Gas v/s diesel for trawlers

[psneeld]

whoaaa........i gotta thunk about this un....Ah, i got it, so simple why didnt i see the answer at first glance. The engines go in the keel and drive a system of pulleys and the mast via a system of clutches and gears controlled electronically via a computer. You boot up your pc, enter your destination and allow the computer to do the rest. A small single electric motor and electric solenoid controled switches should do the trick. Most of the energy to propell the vessel will be provided by him/her up there and the small left over can be provided by a small generator driven electric motor.........................................................................................
Didnt someone make a schooner like this back in the early years of this century? she had three masts computer controlled i beleive

At least what he said made some sense....

There are many possibilities...you just have to decide what works for you and your boat....

 

[Nomad Willy]

march wrote;

"I am sorry but I don't see any efficiency advantages to diesel/electric or diesel/hydraulic over a prop shaft driven by an engine through a transmission."

Of course because there isn't any.

But if you had 4 or 5 propellers and 2 or 3 engines you could design a system that would cruise at 15 knots as a regular single or twin screw boat and then slow down to 7 knots burning less fuel and not under loading an engine. That would be more desirable to many and it could be a very desirable option.

And march there are numerous advantages to DE drive like the ability to run very slow in the harbor. I think there's several maneuverability advantages and more. I have an article on DE in an old PMM and there are numerous advantages that would be well worth a 10 or 15% overall loss of efficiency. But the mag is not yet unpacked. I'd go for it but probably not the installation cost.

 

[Marin]

I like the idea of electric propulsion. It works great for railroads, both straight electric and diesel electric. It works great in large vessels as witness the diesel electric Washington State ferries.

Although it's interesting that the large tankers, bulk carriers, and container ships built today mostly seem to be diesel powered, not diesel-electric or turbine. I'd like to know why that is.

And it works great in vehicles with some limitations.

But so far the advantages of electric drive--- quiet, smooth power--- have eluded the recreational boat market. I assume this is partly cost and partly acceptance.

I don't think converting boats like our old GB to some form of electric drive is cost-effective. But I would find it very interesting to hear from the boat manufacturers themselves why they so far have not viewed electric propulsion in some form as a viable or marketable drive system be it diesel electric, fuel cell, or some other system.

 

[bfloyd4445]

march wrote;

"I am sorry but I don't see any efficiency advantages to diesel/electric or diesel/hydraulic over a prop shaft driven by an engine through a transmission."

Of course because there isn't any.

So you are saying cause you don't see any advantage that science could never find any? Even Albert Einstien admitted that just because he couldnt go any further didnt mean that his theroys were the end. And i don't think there are many others in his class whose theroy's hsave not been superceded in a short time. Facts show electric moves heavy loads more eficiently than any other technology known at this time. Granted a good workable marine system has yet to sail the seas but that dosent mean they won't in the future. To sit around and say, Bah humbug, it cant be done, is an attitude that would have kept us in the dark ages. Isnt it great that there are people out there that say, what if, even when faced with over whelming, it cant be done, comments. Good old orville and wilbur were told it cant be done and today we have squirt powerd aircraft......hummm.....cant be done????

not to be comfortational, one thing i will agree with you about is that it takes the same amount of energy to move a given object a given distance no matter what the power source is. However, as has been proven with autos things like regenerative braking etc. can greatly cut into the out of pocket expense for purchased energy so why cant we do the same for boats? Do you wish we stay with fifties technology when in the near future diesel fuell is likely to be $10.00 per gallon. What would be wrong with a power system that stores wind, sun, water energy for use in powering the vessel? I remember back in 2000 or there abouts when people said electric cars are no good they have no range and a guy in LA got a few phone batteries and a small generator and proceeded to drive accross country in his home built DC converted car. Since then we have advanced considerably, times are changing my friend

God bless, and merry christmas to all

B

 

[Andy G]

Our engine operating manual covers three versions of the "FL 120." These engines are based on the Ford of England Dorset diesel. There are a lot of subtle cubic inch variations in these engines and they're easy to overlook.

The first one is the" FL80." It's based on Ford of England's four-cylinder version of the of the engine called the 2712-E. It is a 254 cu in engine and develops 80 hp @ 2,500 rpm.

The second version is what we have,the "FL120." It is based on the Ford of England 2715-E six cylinder, 380 cu in, naturally aspirated diesel. It develops 120 hp @ 2,500 rpm.

The third version is the turbocharged version. Ford called it the 2704-ET. It is a six-cylinder, 363 cubic inch, turbocharged engine that develops 150 hp @ 2,400 rpm.

The Lehman model numbers for the marinized versions of these engines are 4D254 for the 80 hp four cylinder, 6D380 for the 120 hp six-cylinder engine, and 6D363T for the 150 hp six-cylinder turbocharged engine.

Lehman of New Jersey marinized a lot of different engines over the years, a number of them from Ford of England. As the turbocharged engine you are describing is 160 hp, I suspect it's not one of the three I listed above.

Lehman also marinized the later Ford of England Dover engine. This is the base engine for the "Ford Lehman 135." Lehman actually called them "SP" engines for "Super Power." Ford of England made four variants of this engine.

The Ford (and Lehman) numbers are:

2722E (Lehman model SP90), four cylinder, 254 cu in, 90 hp @ 2,600 rpm.

2725E (Lehman model SP135), six cylinder, 380 cu in, 135 hp @ 2,600 rpm

2726E (Lehman model SP185), six cylinder 363 cu in turbocharged, 185 hp @ 2,500 rpm

2728E (Lehman model SP225), six cylinder 363 cu in turbocharged, 225 hp @ 2,450 rpm

2728E (Lehman model SP275) six cylinder 383 cu in, turbocharged/intercooled, 275 hp @ 2,500 rpm

Again, no 160 hp turbocharged engine in this group. So I don't know what Lehman engines are in the boat you are considering.

The above data was taken from our FL120 manual and the SP-135 manual on the GB owners forum.

That's interesting, thanks for the information.

 

[RickB]

Facts show electric moves heavy loads more eficiently than any other technology known at this time.

Horsepucky

Granted a good workable marine system has yet to sail the seas but that dosent mean they won't in the future.

More Horsepucky

 

[FF]

If I cruise 10hours in idle , I must full power at least 1minute twicw a day to clean the engines. Is it the same with gasoline engines?

NO. And 1 min will not clean the carbon buildup behind the rings, high piston temperature and time is required.

Perhaps a half hour ,,.

The nicest engine room I was able to visit was on a 55-60 ft Motor sailor called Feng Shuay (SP?)

It had a fine setup with the engine mounted an the bow!

The boat was heavy so a 6-71 at 2500lbs was not noticed , the noisemaker was there too.

The engine was walk around standing headroom, and the hull at deck level provided huge storage at eye level.

The shafting was std truck with the tranny at the usual after position absorbing thrust .Windlass , mechanical from the 6-71 with a clutch, no blown fuses.

With todays far lighter engines , and the fact that 60 years later the fore peak still sucks as a place to be , I think this configuration would be of far more interest than a D cell powered boat.

When the decimal moves 2 places on batts , smaller .,lighter, cheaper and far far more powerful, perhaps a noisemaker free (for a week) boat could be built.

 

[sunchaser]

Rick said:

"Horsepucky

More Horsepucky"

Having spent many decades working with electric wheel drives in off road applications, I can only but agree.

Dave Marchand is a pretty bright guy and his comments a few posts ago should be re-read bflloyd. Get off this "jus cause science caint prove it" nonsense and deal with the here and now. Oregon is green I know, but electric drives in our toy boats (at least mine is anyway) is best left out of a gas vs diesel comparison.

 

[Tom.B]

Horsepucky

Correct Potterism is HorseHOCKEY

Study Guide:
Stepchild of the Sun - A Guide to Colonel Potter Slang Or

 

[jeffnick]

Could the reason why diesel/electric is not popular in boats be because boats do not use multiple gears as do land based vehicles? Can you see clutching in and out to change locomotive gears while accelerating?. Electric eliminates the clutch and gearbox, neither of which is used in recreational boating.

 

[RickB]

Could the reason why diesel/electric is not popular in boats be because boats do not use multiple gears as do land based vehicles?

In a word, no.

In more than a word, what do you mean by "boats?" There are many marine applications where D/E makes a great deal of sense for many reasons.

Can you see clutching in and out to change locomotive gears while accelerating?.

Yes, the "clutching" is performed automatically in the very commonly used and very efficient geared locomotive drives used in European railways.

 

[sunchaser]

Jeff

I can assure you my boat has a gearbox - Hurth. It has a 2.5:1 reduction gear with a reverser. Some in fact claim that marine gearboxes have clutches. Furthermore, the propeller is variable speed as I move the throttles up and down. For our slow trawlers, what more do we need and why?

 

[psneeld]

I went to Antarctica and nearly the North Pole on diesel electric boats...

On the way to Iceland...one of the main motors burned up as the insulation on the windings was so bad (WWII vintage)...

We still continued north to within 400 or so miles of the pole on one motor and came all the way back on one engine and a little over 8 knots via Sweden and Denmark liberty/political calls...

 

[RickB]

Although it's interesting that the large tankers, bulk carriers, and container ships built today mostly seem to be diesel powered, not diesel-electric or turbine. I'd like to know why that is.

Because those ships operate for extended periods at a constant speed and load and have hulls optimized for that purpose and driven by engines and propellers optimized for extended operation at a specific power output and ship speed.

There is no advantage to adding another conversion between the fuel tank and the propeller.

Some "parcel tankers" that operate in coastal trades are diesel-electric because a tanker may consume as much power offloading as it does transiting.

Many LNG tankers use steam turbine propulsion because they can utilize the boil-off gas for fuel. The Japanese are building several now and are the leading supplier of boilers these days.

 

[Marin]

Could the reason why diesel/electric is not popular in boats be because boats do not use multiple gears as do land based vehicles? Can you see clutching in and out to change locomotive gears while accelerating?. Electric eliminates the clutch and gearbox, neither of which is used in recreational boating.

Most railroad locomotives have eight engine settings, referred to as "runs"--- run six, run eight. I have no idea how the system works but you can hear the prime mover (diesel engine) "shifting" as the locomotive accelerates and you can see these "shifts" reflected by in the exhaust plume.

 

[markpierce]

Most railroad locomotives have eight engine settings, referred to as "runs"--- run six, run eight. I have no idea how the system works but you can hear the prime mover (diesel engine) "shifting" as the locomotive accelerates and you can see these "shifts" reflected by in the exhaust plume.

Those "shifts" are merely changes in power/throttle settings. Possibly that's due to the throttles being electrically controlled. Most all the diesel-electric railroad locomotives were/are built this way such as from builders EMD, ALCO, and GE. This allowed one engine crew to control multiple locomotives (units). One builder, Baldwin (now long-defunct), however, had pneumatically controlled throttles which allowed "infinite" power settings as there were no "notches." Here, air hoses rather than electrical wires connected locomotives' throttles. Baldwin locomotives couldn't be "MUed" with other builders' locomotives.

Engine controls of a 1950s-era GE 70-ton diesel-electric locomotive (photo taken in 2009):

 

[JD]

Jeff

I can assure you my boat has a gearbox - Hurth. It has a 2.5:1 reduction gear with a reverser. Some in fact claim that marine gearboxes have clutches. Furthermore, the propeller is variable speed as I move the throttles up and down. For our slow trawlers, what more do we need and why?

Rest assured that your gear box has clutches just like the automatic transmission in your car has them. They are in what is called a clutch pack and are either engaged, which means compressed together or not engaged which then allows the engine to turn without transmitting power to the out put shaft. You control if they are in gaged or not buy the lever you push at the helm. One difference in your car and the boat is the car has one more link to the engine by way of the Torque Converter where the boat has a Damper Plate. This is a mechanism that allows your car to stay in gear while you are at a stop light yet there is no forward motion. The torque converter is a turbine affair in which one part is connected to the flywheel and the other is connected to the front shaft on the transmission. As the engine turns at low speed, idle, the Stator and the Rotor turn by each other, but as the engine speed increases the rotor causes pressure on the stator and the stator starts to move thus making the car move. A Torque Converter would not be needed in the car but then you would have to select drive, neutral or reverse constantly. When you were approaching a light you would have to shift into neutral every time just as you do on the boat as you approach the dock. Other wise the engine would stall. The boat transmission is simple because it only needs to select one ratio so it has only one clutch pack where the car transmission needs to select between several ratios and thus becomes more complicated by way of several clutch packs and other items.

More than anyone really wants to know about either I'm sure.

 

[Nomad Willy]

Perhaps the operative word is control.

You can putz around in a harbor at 1 knot and stay in "gear". I think you can reverse instantly at full power AND torque and then without a pause for the clutches slam into reverse. Don't remember the details perfectly as my PMM is in a box still but DE drive is has some really great advantages. Don't remember about efficiency though.

 

[markpierce]

Eric, my builder warned me about changing from forward to reverse saying it must be done at idle/near-idle engine speeds to avoid risk of damage.

 

[JD]

Eric, my builder warned me about changing from forward to reverse saying it must be done at idle/near-idle engine speeds to avoid risk of damage.

Mark,

I'm sure that the damage can be real. It is a lot like slaming into a wall at 50MPH so as you can go backward. A lot easier to slow down then go the other direction. Think about the twisting force on the shafts inside the transmission, the prop, the drive shaft. Even though the damper plate is traveling in the same direction the force of full pressure, then no pressure and then full pressuree all with in a second or so is scary.

 

[RickB]

I have no idea how the system works but you can hear the prime mover (diesel engine) "shifting" as the locomotive accelerates and you can see these "shifts" reflected by in the exhaust plume.

Those "shifts" are the transitions between series and parallel operation of the traction motors. There is a very short period during the transition when no power is delivered. That is what gives the impression of a gear shift as in a truck.

The "runs" or "notches" are governor limits that control the maximum amount of power available to the traction motors in a given configuration. They reduce the risk of overloading a motor by limiting the amount of power the engine can produce.

 

[bfloyd4445]

If I cruise 10hours in idle , I must full power at least 1minute twicw a day to clean the engines. Is it the same with gasoline engines?

NO. And 1 min will not clean the carbon buildup behind the rings, high piston temperature and time is required.

Perhaps a half hour ,,.

The nicest engine room I was able to visit was on a 55-60 ft Motor sailor called Feng Shuay (SP?)

It had a fine setup with the engine mounted an the bow!

The boat was heavy so a 6-71 at 2500lbs was not noticed , the noisemaker was there too.

The engine was walk around standing headroom, and the hull at deck level provided huge storage at eye level.

The shafting was std truck with the tranny at the usual after position absorbing thrust .Windlass , mechanical from the 6-71 with a clutch, no blown fuses.

With todays far lighter engines , and the fact that 60 years later the fore peak still sucks as a place to be , I think this configuration would be of far more interest than a D cell powered boat.

When the decimal moves 2 places on batts , smaller .,lighter, cheaper and far far more powerful, perhaps a noisemaker free (for a week) boat could be built.

yes, electric is quiet but without a noisy generator to run it the technology isnt really applicable to marine use at this time. I thought of solar but its not really possible to put enough solar cells on a small vessel to do the job without generqator backup. Has anyone tryed such a thing I wonder?

As for carbon, why not use a fuel additive to keep the carbon build up in check? I've beern doing that for years in my D pickups and cars.

 

[Nomad Willy]

Mark and JD,

I was talking about diesel-electric drive not clutching reverse gears. I don't think you need to pause or de-throttle w DE systems.

And Mark I definitely do go to idle and pause for 1 to 3 seconds before shifting into reverse unless it would save me from crashing into the float or another boat.

 

[psneeld]

yes, electric is quiet but without a noisy generator to run it the technology isnt really applicable to marine use at this time. I thought of solar but its not really possible to put enough solar cells on a small vessel to do the job without generqator backup. Has anyone tryed such a thing I wonder?

As for carbon, why not use a fuel additive to keep the carbon build up in check? I've beern doing that for years in my D pickups and cars.

Yes for once the boating mags and their infinite advertisements have a company that's advertising it...sorry I don't remember the name...I skimmed over it as useless for the next 5-10 years...WAYYYYY too expensive for my tastes/abilities...

 

[Tom.B]

Aren't pod-drive cruise ships, and the like, diesel-electric driven? Are the pod drives on the new trawlers like this or is it more like a stern-drive system with gears and CV joints?

 

[bfloyd4445]

Aren't pod-drive cruise ships, and the like, diesel-electric driven? Are the pod drives on the new trawlers like this or is it more like a stern-drive system with gears and CV joints?

thats a good question. Will ve tolook into that.

This looks interesting and they apear to be electric motor driven you were right
http://www.nauticexpo.com/boat-manufacturer/pod-drive-ships-20116.html

 

[markpierce]

Aren't pod-drive cruise ships, and the like, diesel-electric driven?

Most all cruise ships, pod-drive or not, are diesel-electric powered. They have multiple diesel engines. They turn on as few or many as needed to meet the power needs at any particular time.

 

[bfloyd4445]

Most all cruise ships, pod-drive or not, are diesel-electric powered. They have multiple diesel engines. They turn on as few or many as needed to meet the power needs at any particular time.

So they are using railroad tecknology. When i finally find what i am looking for in a DeFever 40-41 i plan on experimenting with electric power in a more conventional form. I think an ac electric motor generator driven power system that will power the original prop shaft arrangment the old bost was launched with might end up being very fuel efficient.
Very interesting idea multiple engines for diferent load conditions. I don't remember much of my electric motor training but a single electric motor wired to run on different voltages phases for different loads............naw, way to complicated for a 7-9kt vessel. But if she had a hulll designed to go fast then it would make sense. Wow! Just think of it a trawler that can go freeway speeds!! YAHOOOO

Hummmm......Guess thats why they use it on cruise ships and not toy boats

 

[markpierce]

An interesting arrangement would be a single, keel-protected propeller shaft/propeller turned by an electric motor and two small primary engines and possibly a genset connected to generators. For moving at up to hull speed, one primary engine would be used. Faster speeds (assuming the appropriate hull shape) could be provided by using both engines at the same time. If one primary engine broke down, there would still be the second, or even the genset if both primaries failed. Steering wouldn't be hampered by having only one of two offsetted propeller shafts not operating.

 

[psneeld]

So they are using railroad tecknology. When i finally find what i am looking for in a DeFever 40-41 i plan on experimenting with electric power in a more conventional form. I think an ac electric motor generator driven power system that will power the original prop shaft arrangment the old bost was launched with might end up being very fuel efficient.
Very interesting idea multiple engines for diferent load conditions. I don't remember much of my electric motor training but a single electric motor wired to run on different voltages phases for different loads............naw, way to complicated for a 7-9kt vessel. But if she had a hulll designed to go fast then it would make sense. Wow! Just think of it a trawler that can go freeway speeds!! YAHOOOO

Hummmm......Guess thats why they use it on cruise ships and not toy boats

NOT railroad tech...been around for a LONG time in the maritime industry...big electric motors driven by multiple gensets...I believe the USCGC Glacier 9wwii vintage) had 10 Gensets driving the motors and powering the vessel. She had 2 of the largest electric motors ever built at around 3 stories high.
She was a 15+ knot vessel, designed to break thick ice and ran as many gensets as needed to carry the drive and house load. At any given time one or more were being rebuilt underway.