Ammonia Motors

Gallery opened: March 2005

Updated: 13 Mar 2023

Frot's Ammonia Motor added

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The ammonia motor is a device so obsolete and forgotten that unearthing any information at all has proved quite difficult. The concept is thus; take a tank of ammonia, by which I mean pure liquid anhydrous ammonia, and not the weak aqueous ammonia solution that used to be sold for cleaning purposes. (I can remember my mother having a bottle of "Scrubb's Cloudy Ammonia", though why it was cloudy and who Scrubb was are entirely mysterious) The liquid ammonia is allowed to evaporate, which it does readily at ambient temperature, and the resulting gaseous ammonia used to drive something very like a steam engine.

There are of course serious problems with such a simple process. The exhaust gases are not only choking, but they are actively poisonous, and explosive to boot, so exhausting direct to atmosphere is not an option; there is also the point that ammonia costs money so you don't want to throw it away. Another difficulty is that the evaporation cools down the anhydrous ammonia, the rate at which gas is evolved slows down, and the engine is liable to freeze up.

Emile Lamm* solved both snags in one go by absorbing the exhaust ammonia in a tank of water that surrounded the anhydrous ammonia storage tank. Heat is evolved when the exhaust ammonia dissolves, keeping the anhydrous ammonia warm and aiding its evaporation. This neat process is reminiscent of a similar scheme using caustic soda: see The Soda Locomotives".

* It appears to have been Lamm, anyway. I have so far only discovered one earlier ammonia motor inventor, a Mr Gordon, and technical details are sadly lacking.

From "A History of The Growth of The Steam-Engine" by Robert H Thurston, AMCE

"In 1822, David Gordon patented a road engine, but it is not known whether it was ever built. At about the same time, Mr. Goldsworthy Gurney, who subsequently took an active part in their introduction, stated, in his lectures, that "elementary power is capable of being applied to propel carriages along common roads with great political advantage, and the floating knowledge of the day places the object within reach." He made an ammonia engine- probably the first ever made- and worked it so successfully, that he made use of it in driving a little locomotive."

And that's all he wrote. Unfortunately it leaves it unclear whether Gordon or Gurney devised the ammonia engine.


Left: The Delaporte Ammonia Engine: 1859

The ammonia boiler is at a, with a grate beneath it. Pipe b conducts the ammonia boiled off from aqueous solution to the cylinder d, which has a conventional slide-valve assembly. e is the exhaust (eduction) pipe leading to the condenser and dissolver f, into which water is sprayed by a rose-jet. The ammonia solution passes into the next chamber, from which it is pumped by piston h. It then goes through pipe u to a boiler feed-pump, and then via pipe v back to the boiler, passing through heat exchanger l. The incoming solution is warmed in l by water withdrawn from the bottom of the boiler through the lower pipe visible therein.

Apparently this water "has been deprived by heat of its ammonia" though how this is kept separate from the ammonia solution being pumped in is a good question; possibly it's simply a matter of density. This water, on leaving l by a connection not shown, is cooled and conveyed into the tank t, which is the source of the water sprayed into f.

It's a bit hard to say what the value of this engine was. it appears to have worked on a mixture of ammonia and steam, since the chamber f is referred to as both a condenser and a dissolver. If so, presumably the heat generated by the ammonia dissolving would have worked against the condensation of the steam, which doesn't sound clever.

Delaporte's engine is described in a Knight's book of 1881; however it must have been built long before that, judging by the beam-engine format, which would have been considered very antique in 1881.

From Knight's American Mechanical Dictionary, 1881 Edition


Left: Tellier and Flandrin's Ammonia Carriage: 1860

In 1860 Tellier and Flandrin used liquid ammonia to power omnibuses in the streets of Paris. The same system was later used in New Orleans.

The ammonia evaporated when the pressure on it was released, and after passing through a two-cylinder engine, was dissolved in water and then reclaimed by distillation. The ammonia throttle was presumably the small crank-handle by the side of the tank. Note the (probably ineffective) foot brake.

Source: Transactions of the American Society of Mechanical Engineers, Volume 7, p687. No other reference to Tellier and Flandrin has been found anywhere, which is slightly worrying.

Left: Tellier and Flandrin's Ammonia Carriage: 1860

This diagram of the ammonia carriage is somewhat less than self-explanatory. The tank labelled 'water' is where the ammonia is dissolved after it has been through the engine; in this water tank is a coiled pipe. The water will get hot as the ammonia is dissolved, and I suggest that the heat was used to warm the ammonia before it reached the engine, increasing the power output and perhaps preventing the engine freezing up. It is not clear where the liquid ammonia was stored; the drawing implies that the engine worked submerged in liquid ammonia, but this does not seem very practical.

The two-cylinder engine appears to have slide-valves worked by eccentrics in the usual way. It appears reversing was done by sliding the shaft at the top sideways, with the horizontal lever in the top picture. The driving chains have very small sprockets.

Source: Transactions of the American Society of Mechanical Engineers, 1886, Volume 7, p688


Left: Frot's Ammonia Motor: 1869

The picture shows only the condenser/absorber part of the engine. I quote:

"M. Frot exhibited an ammonia engine at the Paris Exposition of 1867, in which a solution of one part of ammonia in four parts of water was used in a boiler, the mingled gas and vapout from which was used in the cylinder of an engine, and then discharged into a condenser(Fig 225) where it met a spray of ammoniacal water drawn from the boiler and cooled, which, because of its lower temperature, re-absorbed the ammonia, aided by external refrigeration, after which it was pumped again into the boiler. The inventor claimed that it used but one-quarter of the fuel required by a steam-engine of the same power! The mode of action of this engine was identical with that of Delaporte's of 1859. President Barnard, in his report to the US government upon the machinery at the Paris Exposition, took pains to point out and demonstrate clearly that there was no advantage in such an engine except the possible saving of waste in the furnace. This might amount to five percent; not more."

Source: Transactions of the American Society of Mechanical Engineers, Volume 7, p688

Knight states that the engine resembled a steam engine so closely that comparative experiments between steam and ammonia vapour were made with it, and no more is said.

Source: Knight's American Mechanical Dictionary, 1881 Edition


It seems as though there wasn't one. A certain M. Froment was present as an exhibitor at the Universal Fair in Paris, but he was a jeweller and had nothing to do with engines. The adjacent report in the British journal Mechanic's Magazine, date unknown, seems to have confused M. Frot and M. Froment. As far as I can tell, the

Left: Report from Mechanic's Magazine on the Froment Ammonia Engine: 18??

The mode of operation described seems very close, if not identical to, that of the Delaporte Ammonia Engine decribed above.

From Knight's American Mechanical Dictionary, 1881 Edition


Left: Lamm's Ammonia Motor: 1869

The anhydrous ammonia fills the inner tank RR up to the line d; this is surrounded by a water vessel AA. Ammonia boils off and collects in the dome B, going through delivery pipe C and throttle x to the engine valve-chest E. The exhaust leaves the engine via pipe D and is led to the bottom of AA where it is absorbed, warming the water it dissolves in, causing more ammonia to evaporate from B. This description has a bit of a flavour of perpetual motion about it, because there isn't any energy input to the system; the energy is stored in the liquid ammonia in B; unless this is replenished the engine will stop.

The original drawing had some obvious mistakes, which I have corrected.

A few words on Mr Lamm:

"LAMM, Emile, inventor, born in Ay, France, 24 November 1834; died near Mandeville, Louisiana, 12 July 1873. (he was drowned)
As a boy he showed decided mechanical ingenuity, and in 1869 devised an ammoniacal fireless engine for the propulsion of street-cars. The system was tested by street railway companies in New Orleans, New York, St. Louis, and other cities, with satisfactory results; but owing to Mr Lamm's premature death and unfortunate management on the part of the company that controlled the patent, the motor has not been put into practical operation in the United States. The system has been introduced in France and Germany, where it has been improved and perfected, so that at present (1887) it is extensively used for street-cars and vehicles."

Adapted from Appleton's Cyclopedia of American Biography, 1887-1889.

Sci Am Feb 3,1894

The best-known application of Lamm's ammonia power system was the Saint Charles Avenue Streetcar in New Orleans. The line was established as "The New Orleans and Carollton Rail Road Company" in February 1833, and a service began in 1835. Through the early years the cars were successively powered by horses, mules, overhead cables, Lamm's ammonia engines, and steam engines; none were very satisfactory, and it was finally electrified in 1893.


Left: Report on the Horack Ammonia Engine patent: 1891

This is a complicated setup, not explained with any great clarity. It has some strange features, such as two separate boilers. It is not, as far as I can determine, a bottoming cycle making use of the heat rejected from a conventional steam engine; ammonia/water is the only working fluid.

It is not very clear in the diagram but M and Q are the cylinder of a compound engine.

The Horack engine is unknown to Google.

From Industries 14 Aug 1891, p168


Left: Article on the Campbell Ammonia Engine: 1891.

The Campbell ammonia engine, assumed it is correctly described here, does not work on the Lamm principle. Instead, water with ammonia dissolved in it is heated to drive off the ammmona, which after its use in an engine is redissolved in the water; the same approach as the Delaporte engine above. One advantage claimed is that the water was continually reused so there would be no scale deposition; however, the same applies to a conventional condensing steam engine. It is surprising to read that ammonia is a lubricant- I have no idea if this is true or not.
The claim that it used half the amount of fuel raises the eyebrows; if this was really the case I should have thought we would have heard a lot more of Campbell.

Campbell got as far as setting up the Campbell Engine Company, with headquarters were in the Mills Building on Broad and Wall Streets in New York. Shares were issued in 1888 and some certificates have survived.

At present I can discover no other mention of the Campbell system, so it was clearly not a great success.

From Manufacturer & Builder, July 1891


The MacMahon ammonia motor used the Lamm principle of heating the evaporating ammonia by absorbing the exhaust in water. A MacMahon ammonia motor was exhibited at the Chicago Exposition of 1893. It was intended to use it drive small streetcars. (called trams in the UK)

Left: Article on MacMahon's Ammonia Motor: 1892.

Note that when refueling it is necessary to change the ammonia-saturated warm water as well as replenish the supply of anhydrous ammonia.

Manufacturer & Builder, Nov 1892

Left: MacMahon's Ammonia Motor: 1894.

A is the warm water tank, surrounding the anhydrous ammonia cylinder B. Pipe D delivers the ammonia gas to the engine. The exhaust gas leaves the engine via pipe F; and by a sort of injector action causes the warm water in A to circulate through the cylinder jacket C, via inlet pipe G1 and outlet pipe H; this stops the engine from freezing up due to the expansion therein.

Left: Streetcar powered by MacMahon's Ammonia Motor: 1894.

The vertical ammonia engine is mounted on the driver's footplate. The lever R engaged one of two forward gear ratios by a crude system of dog-clutches. The chain drive between the engine and intermediate shaft can be seen at bottom left.

Left: Streetcar powered by MacMahon's Ammonia Motor: 1894.

The anhydrous ammonia tank and its surrounding warm-water bath are mounted longitudinally in the centre of the vehicle.

Two alternative different-sized gears for the final drive can be seen mounted on the axle.


This machine was described in the French journal La Genie Civil (Civil Engineering) in 1894. It makes it clear that once again, it was based on the Lamm system of dissolving the exhaust ammonia in water to maintain evaporation. Unfortunately the article leaves it wholly unclear as to whether the locomotive below was actually built, or if it was just a project. (It is not impossible that some subtlety in the original French has escaped me)
To add to the confusion, the article says that this locomotive was designed for a funicular railway, which imposed the conditions that the loco weighed no more than 3 tonnes, and was no more than 3.05 metres long. However, a funicular railway is one where the carriages are pulled by cable up an incline, so wheel adhesion is not an issue. These are deep (and ammoniacal) waters, Watson.

Left: Side View of the French Ammonia Locomotive: 1894.

Once again there is an anhydrous ammonia tank in the centre, a surrounding warm-water bath, and a nest of tubes between the wheels to increase the surface area for heating.

An interesting feature is that the brakes were also powered by ammonia pressure, which to me seem to have the distinct disadvantage that when you run out of anhydrous ammonia the brakes stop working- something that seems rather less than desirable in a loco intended for steep inclines. Hopefully there was a handbrake as well. In a rare diversion into hard fact, the article tells us that the ammonia brake cylinder was 76mm in diameter.

Left: Section of the French Ammonia Locomotive: 1894.

The water for absorbing the exhaust ammonia is shown in pale blue.

Left: Plan View of the French Ammonia Locomotive: 1894.

Images and information on the French Ammonia Locomotive most kindly provided by Haruyuki Makishima

One thing that all these ammonia engines have in common is a conventional "steam" engine to convert gas pressure to rotary motion. These all have stuffing-boxes, and they are not likely to be perfectly free from leakage. It would therefore seem highly probable that every ammonia motor would carry with it a pungent aroma of leaked ammonia.


The above ammonia engines are workable, though certainly inefficent and probably dangerous. The other area in which "ammonia engines" appear is the much less respectable realm of aspirations to perpetual motion.

There are two kinds of perpetual motion machines. A Perpetual Motion Machine of the First Kind breaks the First Law of Thermodynamics (essentially the principle of conservation of energy) by putting out more energy than goes in; these are clearly impossible. A Perpetual Motion Machine of the Second Kind, or PMMSK, is more subtle; it keeps the First Law, but breaks the Second Law of Thermodynamics, which says that you cannot generate power simply by withdrawing heat energy from one body- you must also reject that heat to a body at a lower temperature.

The classic example of a PMMSK is John Gamgee's well-known "Zeromotor". In 1880 John Gamgee devised an engine in which heat from the surrounding environment boiled liquid ammonia to drive a piston engine. The expansion of the exhaust was then supposed to cause spontaneous condensation of the ammonia, the liquid returning to a reservoir to complete the cycle. Gamgee may have been a crook or he may have been sincere, but if the latter he clearly had not tested the concept in reality. Nonetheless, he persuaded the Chief Engineer of the US Navy, B F Isherwood, of its practicality. Isherwood should have realised that the Zeromotor blatantly violated the Second Law of Thermodynamics, but instead recommended it to several cabinet officers, and even US President Garfield was enthusiastic. A working Zeromotor would have been of enormous benefit to a navy; at this period steamships were fuelled by coal, and long-range naval operations required expensive and far-flung networks of coaling stations scattered over the globe. The range of the ships would only have been limited by provisioning, if they were powered by heat from the very water they floated on.

Naval enthusiasm was short-lived; a working model would function only with the condenser disconnected, and then only unsatisfactorily. The problem is that ammonia must be cooled to -33 degrees Centigrade to make it to condense at atmospheric pressure, and with no part of the engine at that temperature the ammonia simply could not be condensed.
It appears Gamgee was proposing that the ammonia was to be recycled through the traditional condenser applied to marine steam engines, but since this is cooled by sea water in normal use, it could hardly have condensed the ammonia since it had previously boiled it.

John Gamgee is usually described as "A London professor working in Washington DC" which raises an eyebrow. In Britain a professor is a senior figure running a whole university department, and that does not square well with his dubious promotional activities in the USA. One source says that he created London's first artificial ice rink, which would certainly fit in with his interest in ammonia. (Ammonia was once widely used as refrigerant)

Wikipedia tells us only that John Gamgee lived 1841 – 1909, and describes him as a "English physician". It does however tell us a little about his ice-rink activities; he called it a Glaciarium. The Oxford Dictionary of National Biography calls him a "veterinary surgeon and inventor" and gives his dates as 1831–1894. His brother Arthur Gamgee seems to have had a more respectable career in medicine.

Another scheme that John Gamgee was involved in was the construction of a refrigerated hospital ship that would go from port to port, curing Yellow Fever (a most deadly disease) by chilling the patients. This could not have worked- there is no therapy for Yellow Fever to this day. The refrigerated ship story has fascinating ramifications as it brought about the widespread use of nickel steel.

Left: A rare (and possibly unique) diagram of the Gamgee Zeromotor: 1884.

Interestingly, this version of the Zeromotor uses a compound rotary engine, a technology that by by 1884 had been long notorious for poor performance due to inherent sealing difficulties, and thus piling impracticability upon impossibility.
Details of the rotary engine are not given, beyond that it had an eccentric rotor with some sort of sliding vane for sealing.

From The Practical Dictionary of Mechanics, Supplementary volume, by Edward H Knight, 1884. Pub Cassell & Co, London.

The explanation given below is a heavily edited (by me) version of that given by Knight, but nothing has been omitted. Knight does not use the term "Zeromotor", but refers to it as a Thermodynamic Engine. Un-Thermodynamic engine would probably be a better name. Here goes:

Pipe e conducts the ammonia vapor from the dome Ax of boiler A to the High-pressure cylinder B. The pipe d takes the ammonia from the high pressure cylinder B to the low-pressure cylinder B'.
D is the drive-shaft, connected to a large flywheel at the extreme left. The pipe f takes the exhaust from the low-pressure cylinder to the exhaust-vessel E. From this a pipe G leads to a two-stage compressor G,G', using the same rotary configuration as the engine, driven by the shaft D; the two stages of the pump are connected by pipe h. The output from the second stage of the pump is fed back to boiler A via pipe h'.

My astute readers will have spotted at once that this "explanation" actually gives no clue as to how the Zeromotor was supposed to work. If the ammonia is boiled by sea water in A, then what causes it to condense in exhaust-vessel E? Gases get colder as they expand, and there is some evidence that Gamgee thought, or at any rate claimed, that this cooling would be sufficient to make the ammonia condense again.

Knight also completely fails to explain the function of other parts of the machinery shown in the diagram, such as K, which appears to be some sort of heat exchanger. However, we can hardly blame the poor chap as it is not easy to explain the modus operandi of a machine that is a physical impossibility. There is a strong possibility that many of the parts were added simply to make the engine look impressively complex.

It is rather mysterious that the story of the Zeromotor, which is fairly well-known, has virtually no representation on the Web. No doubt this is all part of the General Conspiracy.


The French engineer Charles Tellier was a pioneer in the field of solar energy. In 1885, he installed a roof-top solar collector very similar to the flat-plate collectors used today for heating domestic water. His collector system was composed of ten units made of two iron sheets riveted together and connected by piping to form a single array. The collector plates were filled with ammonia, and after exposure to sunlight, sufficent pressure was created in the ammonia gas to power a water pump that Tellier had placed in his well, at the rate of some 300 gallons per hour during daylight.



The thermodynamic cycle used in conventional power stations is the Rankine cycle. One of its features is that most of the heat is transferred to the water at a constant temperature during boiling, and taken from it at constant temperature during condensing. The Kalina cycle is a relatively new devopment. It uses a mixture of 70% ammonia-30% water as the working fluid, and this offers significant potential efficiency gains over the Rankine cycle. The boiling of the ammonia-water mixture occurs over a range of temperatures, unlike steam, and so the temperature difference between the boiler gases and the fluid can be kept lower; as the gases cool they are directed over tubes containing working fluid at a lower boiling point. Thus the energy extracted from the gases is much greater. The Kalina cycle is well suited to use as a bottoming cycle working from medium or low gas temperatures such as a gas turbine exhaust, with gas inlet temperatures in the range of 400 to 1000 F. The lower the gas temperature, the greater the advantage over the Rankine cycle. It is also favoured for geothermal power generation, where the hot water coming out of the ground is a low-temperature heat source compared with a coal-fired boiler. (A bottoming cycle is a circuit of working fluid added to an existing cycle to exploit the heat rejected. If the original cycle is a conventional steam power plant, the exhaust steam which usually goes to the condenser is going to be at around 79 degF (26 degC) and while there is a lot of heat available, it is at too low a temperature to be of any use for most purposes.)

The condensation of an ammonia-water mixture also occurs over a range of temperatures, and this makes it easier to run an efficient cycle if the available cooling water is not very cool. In the Rankine cycle, warmer cooling water directly reduces the degree of vacuum achievable in the condenser, and hence the cycle efficiency. Changes in the water/ammonia ratio as the fluid goes through the Kalina cycle allow condensation without using impracticably low temperatures. Clever stuff!

The Kalina cycle was invented by Russian èmigrè Alexander Kalina.

I have not so far had time to put together a description of the Kalina cycle that does it justice, but here are some external links to explore:

The Kalina patents This is a great animation, for explanation see link above.

The U.S. Department of Energy built a Kalina cycle power plant in 1991, at the Energy Technology Engineering Center in Canoga Park, California. It said: "Data from the early operating trials confirmed the principle of the Kalina Cycle technology."
However, so far Kalina cycle technology has not got much beyond the experimental stage. With any exotic working fluid, leaks present a possibly serious problem.


There is another way to use ammonia for power generation- burn it as a fuel. There is currently interest in using ammonia as a fuel in IC engines. It delivers hydrogen without having any carbon content. There are obvious problems, such as the toxic nature of ammonia, and some less obvious- ammonia burns slowly compared with a petrol-air mixture.

A notable example of ammonia as a fuel was the XLR-99 rocket engine, which powered the famous X-15 manned research rocketplane. It was the first big man-rated throttleable and restartable liquid propellant rocket engine. The thrust was 262.400 kN (58,990 lbf) in a vacuum and 227.300 kN (51,099 lbf) at sea level. The throttle range was from 50% to 100% thrust, and the restart capability allowed it to be shut off in flight and started again if needed. The XLR-99 was developed and built the by Reaction Motors Division of Thiokol Chemical Company. The propellants were liquid oxygen (LOX) and anhydrous ammonia, fed into the engine by turbine pumps at a flow rate of more than 4500 kg per minute.

Left: The XLR-99 rocket engine, fueled by LOX and anhydrous ammonia.

The XLR-99 made 339 flights between 1959 and 1968.


Refrigeration is not of course a means of power generation- quite the reverse- but it is worth pointing out that ammonia is central to the operation of that most ingenious device the absorption refrigerator. (external link)

See also:

Ammonia is also still very much in use as a vapour-compression refrigerant in industry.
These chaps are quite keen on it: The International Institute of Ammonia Refrigeration as their name might suggest...

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