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Free, unlimited electric power from the salty sea may soon replace gas, diesel engines in marine use.

EVERY so often someone comes up with an idea so simple and apparent that millions of Monday-morning quarterbacks promptly kick themselves and mutter “Now why didn’t I think of that?” Occasionally the idea is completely original. Usually, however, it is an old chestnut that has been kicked around until some bright lad finally dopes out a way to make it work. Ralph E. McCabe, designer and patentee of a practical, new salt water battery, does not claim to be the first to conceive the notion of extracting electric current from the ocean brine. He does claim to be the first to produce a seagoing wet cell that will pull enough juice from Davy Jones’ locker to run a boat and haul a payload!

McCabe’s battery is the result of no sudden stroke of genius. Since he first latched on to the basic idea back in 1948, he has slowly and painfully developed it to its present state of efficiency. During that time no less than 36 model boats have been built and tested at various points in the Atlantic, Pacific and the Gulf of Mexico. His latest models, Mamie and the Eighth Wonder of the World, are each 21 in. long with a 4-1/2 in. beam and they weigh 2-1/2 and 3 lbs. respectively. Each produces a little over one volt and up to three amperes of current, enough to drive them through the water at speeds up to five mph. This, as any boatman can tell you, is quite impressive for a working model of that size. In addition to the propulsion motors, some of the models are fitted with electric fights, foghorns, etc., all operated from the same basic power source.

The theory behind McCabe’s power plant is simply that of the familiar wet battery. The salt water of the sea acts as a conductor of the electric current flowing between a carbon-graphite positive plate and a nickel-zinc negative plate. This current operates a D. C. electric motor which, in turn, drives the boat’s propeller. The plates are corrugated or grooved to provide increased working area without increasing their overall dimensions.

Some of McCabe’s earlier models stalled after a short run due to the polarization or “balancing” of the ions. Eventually this difficulty was overcome and his latest boats have ticked along steadily until the motor brushes or armatures became dirty—a running time of five-and-a-half hours and a distance of some 20 miles. After cleaning they promptly took off again as strong as ever. With stand-by motors and facilities for automatic changeover, there is no reason why such a power plant should not run indefinitely.

McCabe has applied his boat-battery principles to a newly patented flashlight cell which he hopes to have on the market this year. Circular in section, it embodies a grooved carbon-graphite positive rod in the center surrounded by a cylindrical, zinc negative plate, deeply corrugated for increased area. He states that this new arrangement produces twice the amperage of the present cell of similar size and lasts twice as long.

The dry cell set-up, shown in the diagrammatic insert in the lead illustration, suggests an efficient wet battery arrangement suitable for large, seagoing freight and passenger ships. Encased in long tubes stretching fore and aft between the longitudinal bottom members of the conventional double hull, the batteries „ would occupy the space now used for fuel-oil tanks. Subsurface intakes on either side of the bow admit seawater to the battery tubes in a through-flow system that exhausts it from exit vents beneath the stern. The moving water, with its constant saline content, forms a perfect electrical conductor. The current thus generated is fed into banks of storage batteries from whence it can be drawn in an even, steady supply to operate the ship’s propulsive motors and auxiliaries. Such a power plant can be controlled directly from the bridge with no engine room telegraph ‘ necessary. The D.C. motors are instantly reversible under full loads, eliminating heavy reversing gear and increasing the vessel’s maneuverability.

Assembled in short, quickly detachable sections, the battery tubes are easily accessible for cleaning, repair or replacement of worn electrodes. Individual pumps and gate valves, fore and aft, permit any particular battery to be closed off and drained without affecting the others. With a few extra units built in for reserve power, the ship can proceed at normal cruising speed while repairs are completed. At the voyage’s end, plates can be readily pulled and replaced without the necessity of dry-docking the ship.

Similar sea-water battery arrangements can be adapted to small pleasure craft. As shown in the diagram atop page 86, they can be hung in sheet form on either side of a sailing yacht’s keel or spread horizontally across the flatter bottoms of motor cruisers. While the original investment in generating and storage batteries, motors and wiring would undoubtedly equal or exceed the cost of an internal combustion engine with its exhaust pipes, plumbing, tanks, etc., the elimination of dangerous and expensive fuels, engine vibration, noise and mechanical reversing gear would make it well worth while in the long run. It would certainly be far simpler, more easily controlled, lighter and more dependable than today’s cranky power plants.

McCabe feels that while he has developed his sea-water battery to a fairly efficient stage there is still plenty of room for improvement. He hopes, therefore, that some of you MI readers will pick up the ball and carry it a few yards further, “as the amateurs did in the radio field.” With this in mind he offers a free permit to use his improvements in advanced experimentation and will be glad to discuss plans and procedures with any interested amateur. His ideas, however, are patented and can not be used commercially without specific permission.

To encourage their continued development, McCabe plans a series of sea-water-powered boat races late this summer. He explains that initial battery experiments can easily be conducted in the family bathtub if two or three per cent of salt is added to the water.

The basic idea seems perfectly valid and you may get in on the development of a brand new form of marine propulsion—free electric power from the seven salty seas! •

  1. Rick Auricchio says: January 27, 20091:36 am

    Let’s see here.

    100 horsepower, enough for a nice runabout, requires about 75000 watts of power. Round it up to 100kw to account for efficiency losses.

    The model generates 1v * 3a or 3 watts.

    So we’re probably looking at scaling the model up by a factor of 33000 to generate power for 100 horsepower. At that size, we’re looking at a boat way too large to move with only 100hp.

    Modern cruise ships do indeed use electric motive power, but they generate electricity with huge diesel-driven generators.

  2. Casandro says: January 27, 20096:30 am

    Wow, it’s a battery. The electrodes will corrode and consume themselves.

  3. Tracy B. says: January 27, 20094:40 pm

    yes, and the only way to recharge is to get more metal………..perhaps that is what the “caterpillar” was on the “Hunt for Red October”

  4. Richard C says: January 27, 20096:42 pm

    It’s like those “potato clocks” or “lemon batteries”. Nifty little 5th grade science experiments, but there are good reasons we don’t use them for practical power on a large scale.

    The expensive, energy-intensive part of a battery isn’t the electrolyte. It’s the energy needed to refine the materials that make up the electrodes.

  5. Jari says: January 29, 20092:55 pm

    Tracy, as far as I understood, the caterpillar from the Red October used superconducting coils to induce magnetohydrodynamic force to seawater. Similar than this:…

    Really cool looking ship, don’t you agree?

  6. NobodYouWanToKnow says: February 1, 20096:40 am

    See also : Warren Rice’s R&D :

    US Patent # 2,997,013
    Propulsion System


    tres interesant…

  7. Mark Fangue says: June 23, 20092:49 pm

    At least it is an attempt at transportation via clean energy. I think it is a great idea, it just needs to be improved further, but when bolstered with solar panels and/or wave energy it could definitely be viable for commercial size vessels and smaller. It is true that production of the parts to make advanced systems like these are (currently) expensive and it involves less than clean processes to produce, but that is the cost of production. The terrible thing that we are trying to get rid of is the inefficiency of the internal combustion engine, the lubrication fluids it requires, and the neverending demand of oil it requires that exhales tons of pollution. I encourage everyone to continue to work on this design or system and stop bad mouthing it.

  8. Casandro says: June 23, 20092:55 pm


    I’m sorry, but this system is total bolloks. It’s essentially a battery using salt-water. It’s just like using normal non-rechargable batteries. The only difference is that this battery is open and releases, potentionally hazardous, reaction by products into the sea.

    And just like with non-rechargable batteries, you need several hundred times more energy to produce them then you get out of them.

  9. Firebrand38 says: June 23, 20094:45 pm

    “At least it is an attempt”? What’s that supposed to mean? Coming up with an invention that costs a dime to make, sells for a dollar and is habit forming is a great idea but like the great idea of low taxes requires a little more effort to make it work.

    “Need to be improved”? You gotta have something in the first place to improve it.

  10. Paul says: March 11, 201011:28 am

    @Casandro & Firebrand38
    so what have you guys ever come up with that is better? Very little I should imagine.
    The principle is perfectly sound. Although we may not be able to do it, or something similar with todays technology, doesn’t mean we will never be able to.
    Open your mind!

  11. Casandro says: March 11, 201012:13 pm

    Well I do have something that is better than this: Normal non-rechargable batteries, or Diesel engines.
    This is nothing more than a galvanic cell.…

    The principle works and you can actually build something like that at home. Just take some aluminium foil (“tin foil” will do, too) and some copper wire and put both into salt-water. Between the 2 metals you will get a voltage and probably enought current to run a small lamp. Now leave it on for a few days. What will happen is that one of the metals will dissolve while the other one will get a coating and the battery will have stopped working. Now replacing the water won’t change a thing. If you replace both pieces of metal without replacing the water it will work again.

    This has nothing to do with having a closed mind. It has something to do with thinking something through and using logic and knownledge to see what will happen.

  12. Firebrand38 says: March 14, 20108:57 am

    Paul: Very juvenile argument. At this point it’s only your opinion that the principle is sound unless of course you have a little thing called “proof”? Lot more useful than mindless enthusiasm.

  13. Robert says: April 2, 20107:06 pm

    Nice drawings at the top of the page. The only problem is that they are just that: drawings. This would never get off the ground or water. Try scaling it up and watch the size of everything get waaaay beyond feasibility for propulsion. Man, it’s amazing how giddy even these magazines get, whenever “free” energy is supposedly mastered to cure the world’s problems. This is old news with the same results – fine for a lamp, but not feasibly possible to run a large ship – or even a normal sized runabout.

  14. Casandro says: April 2, 201011:32 pm

    @robert Actually it would scale. You could build that fairly large. However it’s not free energy. It’s a simple battery. No magic or free energy there. Of course it would work, for a while until the battery runs out. Just as with any battery this would mean that the metal on one side would be corroded away. The really bad thing about that idea is that it uses sea water and that the battery is open. This means that not only the efficiency will be lower, but also many reaction by products would go into the sea. That’s probably a bad idea.

  15. jayessell says: April 3, 201010:14 am

    Paul, what is your DVD region number?
    (It’s not off topic.)

  16. Firebrand38 says: April 3, 201011:41 am

    jayessell: He’s a Region 1. Probably a janitor at General Electric in Cincinnati.

  17. Douglas says: July 9, 20104:36 pm

    The point to overcome here would be to develop electrodes that are able to attract the ions nessessary to generate power but do not react themselves. I have no idea if this is possible since I am not a chemist nor a physicist. Imagine a material which is attracted to sodium but repels chlorine, and another which is oppisite. Any combination of this should work including the many trace elements in seawater. As long as the electrodes themselves remain intact they could be cleaned of the attracted material. As I said, I have no idea whether this is possible or feasible. But many of todays commonplace items and processess were once thought of as impossible or unfeasable.

  18. Firebrand38 says: July 9, 20104:55 pm

    Douglas: Wow! Now that the hard part is done of imagining a material which is attracted to sodium but repels chlorine, and another which is opposite we can proceed to get financing for this thing. Thanks for taking care of the heavy lifting! That’s like I don’t know about economics but it seems to me that you could make a lot of money buying stocks when they’re priced low and then selling them when the price goes up!

    Don’t be like that idiot Paul who believes that I can’t criticize a suggestion from 1954 that never took off just because I never designed a seawater powered ship.

    Important safety tip, a lot of those commonplace items are here because someone knew chemistry and/or physics (or engineering).

  19. salt says: July 20, 20108:39 pm

    I have tried making a wet cell battery using Mccabe theory to run a boat. I have found after several test that the zinc- carbon electrodes combination works the best.

    But after running a small D.C motor for 30 seconds it stopped working. Then I gave it a rest for 5 mins , washed the electrodes and it worked again.

    Can anyone tell me how I can make it run for atleast 5 mins. thanks

  20. Tom Hernon says: August 8, 20108:20 pm

    We are building a 26 foot electric boat that has the new batteries and charging system that is being used in the new chevy Volt. We are also looking for 10 small green generators that will help recharge the batteries. 1 Sun, 2 Wind, ext… Our new batteries will move the boat at 15 knots for 16 hours on a single charge. We hope the green systems we develop can boost that to 20 knots for 24 hours. Our gas generator can then kick in. We are planing on sailing the boat through the north west passage in July 2012. If anyone has any ideas and want to be involved in this project please contact me at [email protected] We have several engeneers from GM helping us along with my son (mach eng) our business partner (marine eng) and more joining the team soon… We need Ideas please help…

  21. Manoj says: August 12, 20106:34 am

    Can I know how much electrode is left behind unusable before cleaning and at last when no more cleaning possible. My idea consumes total electrode material.

  22. Firebrand38 says: August 12, 201011:07 am

    Manoj: Can any man truly know how much electrode is left behind unusable before cleaning and at last when no more cleaning possible?

  23. Casandro says: August 12, 201011:10 am

    @firebrand38 Yes you can calculate that. You need to know the chemical reaction then you can easily calculate it. Or of course you can build a small model and extrapolate. It should be linear with the charge you pull out of it.

  24. Firebrand38 says: August 12, 201011:21 am

    Casandro: Don’t talk about it, do it!

    And yes, I was being sarcastic towards yet another brilliant poster addressing a question to the author of an article published in 1954.

  25. Casandro says: August 12, 201012:08 pm

    @Firebrand38: Let’s make an estimate.

    OK, this is a zinc lead battery. Therefore it has a voltage of about 0.7 volts. Assuming a required power of about a Megawatt, which is probably little for such a large ship, you have about a Megaampere of current flowing. (with some care, this can be done easily)

    Now an Ampere is defined by 6.24e18 electrons per second. In the reactions taking place in the battery, you get 2 electrons out of each metal atom which reacts. So this means to get the 6.24e24 electrons a second you need 3.12e24 atoms of each metal per second. That’s about 5 mol per second, or about a kilogram of lead or 300 gramms of zinc. So about 1.3 kilograms of material would react every second. That’s about 112 tons a day for a small 1 Megawatt engine. (that’s about 1400 hp)

  26. Manoj says: August 15, 20108:09 am

    I’m sure its only design factor that’ll work.

  27. Firebrand38 says: August 15, 201011:04 am

    Manoj: Tell you what Edison, build it and they’ll come.

  28. Glen says: March 4, 201112:36 pm

    Ok , Let use A Big scale , Let’s Look at the Power it will take to Run , this new Ele. Train Across country, From cost to cost? and the water at each end, and the Batteries all the way from point to point, and at each end at the water’s edges Working and making Hydrogen, as a by product and charging the batteries all the time, . With the water moving in a Great Concrete tanks, at numerous points with batteries from point to point, and the hole way from point to point of the ele. train, and by it moving it could make some of it own power also by the movement and that energy could be stored in the very same batteries, and #1 not take as much power away from the main power grid, and the excess power from point to point, could be used as an over flow back to the main power grid, at the high or low volt side of the power made over all. Float that Boat on land and push the movement in with a Propane Motor after the ele. levitates the train.

    See basics use of levitating weight is to, = Levitation = Super Conductors + Earth Magnets + Liquid Nitrogen = Levitation

  29. Toronto says: March 4, 20112:26 pm

    No, you build a coast-to-coast canal in the form of a giant sluice box, and you slowly rock it back a forth, raising one end at a time. Cargo barges flow downhill from Long Beach to Myrtle Beach (via Phoenix, Lubbock, and of course, Roswell.) The weight of the cargo is insignificant compared to the weight of the canal and its water, and since it always returns to the same position, the energy loss is obviously zero…

  30. chuck stone says: December 23, 20113:16 am

    It is wise for thinkers to kick ideas around in hope of discovering an alternative to the established technology. In aerospace that is called “Brainstorming”. While the first person to advocate a new idea my miss the target, hopefully that effort will motivate others to counteroffer their ideas. This is much better than having people only complain about the bad condition with no ideas to counter offer.

    We are building an engine that uses water to power an otto cycle engine. That engine could well push a boat with adequate power. Go to Google and we explain why and how we are proceeding with a demonstration project. The established companies stay with what already works and what they feel is a low risk with only minor change0s.

    The pressure from “BIG OIL” to keep everyone on oil based fuels is enormous. The denial that the oil will ever run out is very short sighted. America is so dependent upon oil for fuel, they waste billions in wars to gain or sustain control of foreign oil. If just a portion of that money was put into an honest effort to get off the oil, we would already have enough alternatives to oil that we would not go to war for oil in the future. Cost of transportation would drop and that means cost of goods would drop for the consumer. When $5.00 a gallon gasoline hits the consumer changes will happen for the 99% of Americans who work for a living. Smaller cars with higher mileage will come into play. Electric cars and trucks will become more common. But what will happen to the business of shipping by water when the oil wells run dry? Or the cost become too high. Someone should be working on that problem – that is what is behind the idea of using salt water to power a boat.

    I for one say “GOD Bless” and full speed ahead to the inventor.


    To the critics – “The price of honest respect for your criticism is a better idea to solve the problem”.

  31. Al says: February 29, 201210:34 am

    I actually thought I was the first person to come up with this idea I got so excited that I had to google “boat that runs off water” now that we have some innovative thinkers here I say we should come together as a team and make this happen. You know Will Smith said something powerful and it reminded me of people who say things that are impossible or unrealistic the message really starts at 5:29…

  32. Casandro says: February 29, 201210:41 am

    Well in this case we actually _know_ what happens inside such a system. It is something which is well understood for many decades. Every chemistry student can tell you what it does. The water is completely irrelevant, it’s only there to make ions flow. It’s a wet battery, even the article states it. It runs off the parts of the battery, but not the water.…

  33. TOM HERNON says: February 29, 201211:07 am

    I am working on just such a boat only with several charging systems working together to power a 26 foot boat at 15 knots on free energy… I am in Michigan and could use smart people to help…

  34. saltboat says: November 14, 20123:12 pm

    well well well i thought i was the only man to think of this too! its been in my head for a long time now and just did a google search today and there it was! i see the probem of the battery corroding and im very sure there is a solution to the problem, it just needs a group of determind people to get the solution whitch is sitting there somewere. anyone intrested in making a facebook page were we can share ideas, our models, ect?

  35. 007jbond says: February 19, 20133:51 pm

    I’m new to this site but have extensive experience in this feild,
    By super heating a conductor in a pressurised chamber containing sea water, gas is produced, by compressing the gas and pumping the gas into a chamber, the gases can then be flowed into a hydrogen cell. ( via the cat, negative, and also using solar or wind to positively charge the carbon plates, thus producing a regenerative cell. )
    Electronics are a big part of this system, however, the cell is condensed.
    This system will and can operate efficiently via genset, I.e DPBLDVC motor.

    I have further details on this.

    Please email. [email protected].

    Heat is a big part of this system, the heat sink sources can be obtained from a number of installations on such a developed unit like this.
    Contact me.


  36. tsmth47201 says: June 29, 201311:27 pm

    Hang booms off side of ship to either dust or aerosol the electrolytic compound into the seawater, use natural conductivity to collect from as large an area as needed. Dust can be fine enough to decay before sinks too far. Conductors can be hung from booms to collect current more efficiently if needed. Provided dusting the area works, find a material that takes less than 112 tons of it to produce a megawatt a day. Maybe can determine a vibration frequency that could speed decay and produce more electric from a smaller area.

  37. al_packer says: July 3, 20139:41 pm

    There is a well-proven method for obtaining “free” energy to propel a boat. Vessels have been clocked at over 60 knots using it, and cargoes of all sorts have been carried by these boats. The system is so simple that it can be built by a villager in a third world country, although it has also been used in some of the most high-tech boats ever built. What is this system? It’s called “sail”.

    Oh, yes, having “loose” electrical currents around a boat hull is a very bad idea if there is any wet metal in the boat’s hull. We had an aluminum-hulled boat in a local boat yard a few years back whose skin was paper-thin in spots due to galvanic action (the hull was in effect the anode in a battery with sea water as the electrolyte and the bronze fittings the cathodes. Result: Quarter-million dollar yacht a total loss.

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