The “Socité de Moteurs Salmson” was founded by Emile Salmson. Before, it was dedicated to the manufacture of equipment and tools.

“Salmson logo”

-Curiously, in 1908 it began to produce engines as rare and complex as those of the barrel type, which in the case of Salmson were called “Obus”, perhaps because of its shape.

-The place where this activity began was the Boulogne-Billancourt factory, Seine, near Paris.

-That same year, Obus A and B came out.

-The A in the illustration had 7 cylinders and two pistons in each of them. It gave 55 CV.

“Salmson 55 CV barrel engine”

-There were other “barrel” or “revolver” type engines such as the C and D of 1910, the E and F of 1911 and the K of 1912.

“Salmson type E”

-All known as “Obus”, (bombshell in English) but perhaps the most deserved name was for the K model.

“Salmson K”

-The K had 7 double cylinders and 14 pistons, which drove two extreme inclined plates, oscillating.

-Salmson acquires the licenses for the engines from the Swiss company “Patents Swiss Canton-Unné” to manufacture them in France.

-They were better known as “Swiss Canton-Unné.”

-These engines were not common as they were fixed, water-cooled radials, requiring radiators, either between cylinders or separately.

-There were 5-, 7- and 9-cylinder engines and also in double row.

-At first glance, the appearance of all the red copper cylinder liners stands out.

“Salmson Canton-Unné, 5 and 7 cylinders”

-The radiators are between the cylinders.

-The cylinder heads are interconnected and at the top of these two engines there is a small supply tank to maintain the level of the cooling water.

“Salmson C-U 9-cylinder”

-Magnificent looking because, as has already been said, they had their inner steel cylinders and had shiny red copper sleeves.

-In this case it requires separate radiators.

-We see the lower cylinders interconnected by the bases and the upper ones by the cylinder heads.

“Salmson engine with radiators”

-In this case it is an M9 on a Bleriot. But it was in 1911 when the A7 and A5 engines were made, followed by the manufacture of the C9 in 1912.

A radial B model engine with horizontal transmission is also from 1912. This architecture was used by other manufacturers of the time.

“Salmson B, horizontal”

-We note that these motors have a vertical outlet as well.

-The B model gave way to the adaptation, with the same system, of what is known as the first engine practically built by Salmson, the M7, with 11 liters of displacement and which gave 85 CV at 1,250 rpm. The M9 version would follow, with 9 cylinders and 130 CV.

-But we are going to take advantage of the topic of engines with horizontal output to show the M7 with this way of working.

“Salmson M7, horizontal”

-Later another engine came out with the same layout giving 150 CV. The reduction was 1.8 to 1.

“Salmson horizontal, 150 CV”

-Between 1912 and 1914, Salmson granted the rights to manufacture its engines to the Dudbridge Iron Works Ltd. of Gloucester in England, although it was later learned that the B9 and M9 were subcontracted for their manufacture to Williams and Robinson Ltd. See .

-From 1913 is the following photograph of a horizontal engine with a 90° angled transmission and giving 180 CV.

“Salmson horizontal installation”

-The A9 (sometimes confused with the later 9A), started with 230 CV, rising to 240 CV at 1,280 rpm, in the process of its development.

“Salmson A9”

-In the photograph it seems that it already uses a kind of Naca-type fairing ring, but if we look closely it is the exhaust manifold because the cylinder outlet exhaust pipes are introduced into the ring and around the periphery of it there are exits to the outside.

-In the following diagram of the A9 we have a front view, with a propeller and the two branches of the intake manifold with two carburetors at the ends, very low.

“Salmson A9, schematic drawing”

-And in an extreme example, the same layout as the A9 but with larger extensions for the intake ducts. The carburetors were Zenith.

“Salmson A9”

-By coupling two A9 engines, the 18 cylinder with 23 liters of total displacement was obtained. This happened in 1913.

-The Salmson M9, shown without gear and with propeller and then with gearbox. They did not have a master connecting rod.

“Two Salmson M9 engines”

-In 1913, a double version of the M7 came out with two coupled rows, that is, a 14-cylinder engine that gave 220 CV.

-The 9C (or C9?) water-cooled radials had several versions such as Cm, Cmb and the 18Cm, which was a union of two 9Cm engines. They were from 1912/1913 as well.

“Salmson 9Cm”

-In Russia, near Moscow, a Salmson factory was opened with more than 20 thousand square meters of surface area.

“Salmson 9Cm”

-In the illustration, the 9Cm appears with front radiators and supply tanks at the top of the engine.

-The 18Cm engines were one of the last water-cooled ones from Salmson. The 18Cmb, from 1923, gave 520 CV and was a special and very robust engine for tests, raids, and competitions. They were the double version of the 9Cm.

“Salmson 9Cm”

“Salmson 18Cm”

-The P9 model from 1915 did not work out because of constant breakdowns due to material and assembly defects.

The R9, from 1915/1916, had aluminum pistons and gave 160 CV. In 1916 the water-cooled X9 was also released. This engine gave 150 CV

“Salmson X9”

-During 1917, they made the Z9 (a C-U Z9, variant giving 260 CV) that gave 250 CV at 1,600 rpm. In this engine the connecting-rod system was changed to one master connecting rod and eight slave rods.

“Salmson 9Zg version”

“Salmson Z9”

-It was a water-cooled engine that was used on Farman, Hanriot, Caudron, Salmson airplanes and on some airships.

-In 1921 the 18-cylinder version of this Z9 would be made and it would be the Z18 giving 500 CV at 1,600 rpm. It was the union of two Z9 cylinder blocks and was used as a test engine only. It would give 560 CV at 1,700 rpm.

-During war times, significant quantities of 130 CV Clerget engines were manufactured at the Salmson factory.

-Around 1922 the line of water-cooled engines under Canton-Unné licenses was broken and new families of air-cooled engines with their own technology began.

“Salmson 9RA”

-Once the war was over, the demands are no longer state-based and they also go in search of various powers.

-It seems that the first one was the air-cooled 9RA that was derived from the Canton-Unné 9R (?). It gave 220 CV.

-It seems that the identification of the engines also changed because the number of cylinders was placed before the letters of the series. Before it was the other way around, first the letter and then the number.

-A new era of sports and tourism aviation was beginning, so small powers were more necessary for the new airplanes that were being designed.

“Salmson 3Ad”

“Salmson 3AD, schematic drawing”

-The arrangement is not the usual one for fixed radial engines since it places a cylinder at the bottom, which would collect all the oil from inside. Usually there is a vertical cylinder at the top so that there is space for a small collection tank at the lowest point.

“Salmson 3Ad installation”

-Using the same size of cylinders, the 5, 7 and 9 cylinder engines would be made and the 6Ad would be made up of two engines alternated with the 3Ad.

“Salmson 7Ac cross-section”

-In the following illustration we see another front cross-section of the same engine and the position of the master connecting rod in cylinder number 4. There is no rule, it always depends on the tests that are done and the main connecting rod is in the place that affects the least, or where the engine vibrates less. It gave 95 CV.

“Salmson 7Ac frontal cross-section”

“Salmson 7 Aca”

-Continuing with the Ac series engines, the 9-cylinder version was the 9Ac, giving 120 CV. The bore was 100 mm and the stroke was 130 mm.

-Do not confuse the Ad series engines of very small power with the Ac engines of more than double, with the same number of cylinders.

-Thus the 3Ad gave 16 CV, the 6Ad from 1925 gave 25 CV and the 9Ad reached 40/45 CV (50 CV at 2,000 rpm).

“The Salmson 9Ad at the Brussels museum”

-The 9Ad was a small, air-cooled radial engine that was mounted on the Caudron, Mauboussin, Klemm, Couzinet (3 engines) model 30, etc.

“Salmson 9Adb”

-The 9Adb cylinders measured 70 x x86 mm and produced only 45 CV.

-The 9Adr was geared. By 1930, another British company built Salmson engines: British Salmson Aero Engines.

“Nice view of the Salmson 9Adr”

-As a curiosity, the engines built in England changed the name, so the 9AD and 9Adr became AD9 and AD9R and were seen mounted on the Comper CLH7, Boulton-Paul P41 and Angus Aquila.

“British Salmson AD9 MkII”

-In England the ADs were built with 3, 6 and 9 cylinders.

-The ACs were made with 5 cylinders (65 CV), 7 cylinders (95 CV) and 9 cylinders (120 CV). But the first to appear was the 9-cylinder followed by the 5- and 7-cylinders.

-We return to France. The air-cooled 9Abs are very similar to the water-cooled 1917 Z9s.

“Salmson 9Ab”

“Salmson 9Ab”

-By joining two 9Ab blocks, the 18Ab came out, in 1926. It gave 550 CV.

-This same engine with supercharger was renamed 18Abs and gave 635 CV at sea level.

“Two Salmson 18Ab engines”

-Two different versions of 18Ab are shown here. As in many Salmsons, the exhausts were joined to a front manifold and to the outside by two pipes, in this case located at “3” and “9”.

-The 9Na gave 300 CV at 1,800 rpm. The supercharged version was the 9Nas, with 380 CV.

“Salmson 9Na”

-The 9Nc had 10 mm more stroke than the Ac, and gave 135 CV. As the 9Ncs had a Rateau compressor, it gave 165 CV.

“Salmson 9Nc”

-The 9Nd rotated at higher revolutions, and compared to the 9Nc, it increased its power to 205 CV at takeoff.

“Salmson 9Nc, another view”

-The 9Nh engine was intended for use on helicopters.

“Salmson 9Nh”

-Below, a difficult photograph of a 5AP.OI, which did its 100-hour test between April 19 and May 3, 1939.

“Salmson “AP.OI”

-By 1932 the engines that were marketed were mainly those with 9 and 18 cylinders as we see in the following ad:

“Salmson ad from the 1930s”

-And in a way they would be the following:

-9Adb, 45 CV.
-9Adrs, 60 / 80 CV
-7Ac, 95 CV.
-9Ac, 120 CV.
-9Nc, 135 CV.
-9Nct, 135 / 170 CV.
-9Ab, 230 CV.
-9Na, 300 CV.
-9Nas, 300 / 450 CV.
-18Ab, 500 CV, y
-18Abs 500/650 CV.

“9Adrs, with reduction gear and supercharging”

-As we have observed, Salmson's product offer was complete between 45 to 650 CV.

-Around 1934, inverted, in-line, 6-cylinder engines were tested, such as the 6Af, 6Ag or 6Te that gave 170 CV at 2,300 rpm, reaching a maximum of 188 CV at 2,350 rpm.

-This last supercharged one was the 6Tes that gave 250 CV.

-There were other engines that were not well known such as the 12 Vars, an attempt to build a competition engine. It was Air-cooled, and with 12 inverted-V cylinders it gave 450 CV.

-Another frustrated attempt in 1916 was the C12, which was abandoned shortly after.

-The C12 was a 12-cylinder W, with three rows of four cylinders each.

-The gearbox that was used in the Salmson 9Adr is not common in a radial engine. A French collaborator (Durand Gilles) who owns one and also "Manuel de Entretien" has been kind enough to send me an illustration with the details of this gearbox.

“Durand's Salmson 9Adr”

“Front detail of the Salmson 9Adr”

-The crankshaft has an extension with a small pinion that gears with an inner teethed crown of a much larger diameter, thus producing the reduction.

-It is original in concept because as a result there is no continuous line of traction. It is neither a unique case since later, another case has already been seen with the Allison V12 engines of the US Army's P-40 Warhawk aircraft. which also had this type of gear.

“We are dealing with the latest example of this picture”

“Salmson 9 Aers, 75 CV”

-Due to the difference in height between the engine shaft and that of the propeller, a type “f” gearbox is used, as we can see in the above illustration.

“Salmson 7-cylinder with superposed gearbox”

-Below we see an airplane that used the Salmson-Szydolowski, special-architecture engine. See main text with this compound name.

“Airplane with Salmson 250 engine”

-This aircraft has a very special engine fairing with a large number of slots for air to escape from the inside.

-There also is a front circular shutter to control the air circulating through the engine compartment.

“Two Salmsons, the 300 CV horizontal one and the 150 CV one”

“By illustration these Salmsons use the same cylinders"

-The Salmson engines were built with licenses from the Swiss “Canton-Unné”, which is why the following photograph is identified as that of a “Salmson-Canton/Unné” engine.

“Canton-Unné made by Salmson on a aircraft”

“Salmson C12”

-During the Second World War, and in the midst of the German occupation, the Argus AS10c were manufactured like the Salmson AS8, with 240/260 CV depending on which version it was, the -04 or the -06, for example.

“Salmson AS8-04, installed”

-After the war, the 5AP sports engine that we already saw in this text was continued to be manufactured.

-In the post-war advertisement that we show, the 5-, 7- and 9-cylinder radials are offered, as well as the AS8.00.(8AS.00).

-Eventually, in 1951, the Salmson company was liquidated.

-We close this chapter with the aforementioned ad and also with a photograph of the SM-1 airplane from Salmson itself in which the engines were curiously placed one on each side of the fuselage and through transmissions and gearboxes for direction changes, to the wing propellers.

“Salmson post WWII ad”

“Curious installation of some Salmson engines”

-We now add the addendums planned for this chapter of Salmson compiled after the 2003 edition, with information collected from new publications and especially from “in situ” visits to Aeronautical Museums.

-A crankshaft, connection-rod system and piston system of a Salmson Canton-Unné, which is on display at the Turin Polytechnic. You can also see the enormous masses that counterbalance the rod-system assembly with its pistons, on the opposite side of the crankshaft neck.

“Salmson Canton-Unné connection-rod system”

-It is, as we see, a nine-cylinder fixed radial. Probably a water-cooled model.

-But more surprising are the six cams for the distribution and actuation of the valves.

“Distribution cams”

-Although four cams appear at first glance, there are two others interspersed below this drum, which also rotates at a different speed from the crankshaft that passes through the center.

-Curiously, it does not use a master connecting rod but rather a collar where all the connecting rods come together.

Note from the Author: In the Salmson engine we have seen the two fixed masses of the crankshaft to counterbalance the connection-rod assembly

-Shortly later they would become floating (or at least one of them) to compensate for the vibrations that occur while the engine is running due to the intermittent explosions in the chambers.

“Photo of the Salmson B9 from L’Aeroteca

-A photo of an Elizalde B-9 connecting-rod system is attached. The masses compensate for the opposite rod-system. The rear mass is fixed and what we see is floating due to the two shafts and housings being very loose. The centrifugal force keeps it strongly outward but allows it to act as a damper if there are vibrations in the assembly.

-The personnel who observe starting or stopping these engines hear metallic noises when the rotation is slow. The masses fall on descent and hit again when they are raised.

-This sharp metallic knock has raised more than one alarm among those who do not know this system.

-A barrel engine picture has been obtained that is identified as a Salmson type-K, something different in appearance from the K Obus in the main text.

-The possible cone of the propeller is what gives the shape of the aforementioned K.

“Salmson K?”

-We take this opportunity to include a photograph of the M7.

“Salmson M7”

-And also the Salmson P9 engine.

-Both are water cooled and were clearly licensed by Canton-Unné.

“Salmson P9”

“Salmson AZ9”

-The Salmson AZ9 has a formidable reduction gear as we can see in the above photo.

-The AD3 engine (actually 3AD), this time located in the USA where we see a curiosity: the normal propeller has small blades at 90°, undoubtedly to cool the engine.

“Salmson 3AD”

“Salmson Z9”

-In 1917, the air-cooled Z9 engine was experimentally made. It gave 230 CV at 1,500 rpm.

-Remember that the Canton-Unné licenses were for water-cooled engines.

“Salmson 9AC”

-The 9-cylinder 9AC gave 120 CV at 1,800 rpm. It had a front exhaust ring.

“Salmson 9AD”

-The 9AD was a small engine giving 40 CV at 2,000 rpm.

-The 9ADr model was geared.

-An engine with a gearbox is represented below. It is the 9 AErs that has superposed gears with an interesting appearance. It is an engine from 1934 and gave 75 CV at 2,850 rpm.

“Salmson 9 AErs”

-Salmson also made in-line engines like the 6TE, an air-cooled, inverted six-cylinder. It was the brand's first design of this type. This engine was made in 1935 and gave 170 CV.

“Salmson 6 TE”

-Below a new snapshot of the Salmson SH-18 engine, made according to Szydolowski's design, from a two-stroke Diesel engine.

-But curiously with two pistons per cylinder with a different stroke and a single chamber for both.

“Salmson SH-18”

-Finally we present a front view of the five-cylinder engine, the 5 AP-01.

“El 5 AP-01”

-This 5-cylinder engine produced 83 CV at 2,300 rpm.

-In the Le Bourget Air and Space Museum Reserve (MAE) there is a obus-type barrel engine, model C, which we show below.

“Salmson C model”

“Salmson Obus C model”

“Salmson type B from the same MAE reserve stock”

“Salmson AD3”

“Salmson 9 ADR”

“Salmson A9, annular exhaust manifold”

“Salmson AP.OI, at the MAE”

“Salmson M ó P”

“Another Salmson barrel-type engine at the MAE”

On the left side of the engine you can see a wooden wheel that enables the engine to be turned and to observe the inclined plate, the connecting rods and how everything works inside there. The cover is transparent.

“The same engine on the other side”

“Mechanism details”

-The special Salmson 18-cylinder double-row radial is the one we are going to discuss next. It is special because the two rows are not alternated, but fully aligned.

“Salmson 18 cylinders at the MAE”

-It is not a common way in this type of engine and this leads to poorer cooling of the rear cylinders, although only in an in-line cylinder engine. It's an impression.

-Many radials have cam plates front and rear. In this case all the rocker arms pivot on the front cylinder and reach the rear valves with extraordinarily longer rocker arms. The dish tracks are all in front.

“Detail of the cylinders in the Salmson 18”

-Another small 9-cylinder Salmson can be admired today in the private collection of J. Castellsaguer of Mataró, Catalonia, Spain.

“Salmson 9 AD”

-The front collar through which the ignition ramp cables run are lacking.

From Appendix 6: The 110 CV engine is not clear enough in the main text, which is why another of the same type is provided.

“Salmson water-cooled 9-cylinder”

-The following photographs of models built by this brand are from 1914. They are water cooled and licensed by Canton-Unné.

“The 7-cylinder Salmson radial”

“Another view of the Salmson 9-cylinder”

-A view of the Salmson AC.7 is offered below as it is not included in the main text. It is an air cooled engine.

“Salmson AC.7 side view”

-Now we can offer the SH-18 model mentioned in the main text in an almost side view to be able to see more details of its unusual construction. It was a Diesel engine that gave 600 CV..

“Salmson SH-18”

-Two new clearer photographs.

“Salmson M7, horizontal”

-In the previous M7 we see the cylinder heads and the location of the magneto more clearly.

“Salmson A of 55 CV, sharper image”

-The A is a double barrel type, with the combustion chamber in the center of each cylinder.

-The 12 Vars is an air-cooled, inverted-V 12-cylinder with a power of 450 CV at 3,800 rpm and at 4,000 meters of altitude.

-We see a superimposed gearbox with a reduction of 23/40.

“Salmson 12 Vars”

-The small 9 Aers radial that gave 75 CV at 2,850 rpm and 85 CV at 2,950 rpm with gearbox is shown below.

“Salmson 9 Aers”

From Appendix 9: We have located another Salmson of the barrel or revolver type. This time it is not one of those mentioned in the main text chapter. It's even more beautiful.

-Similar to the K, also called “Obus”. It has seven cylinders with double opposed pistons in each, two inclined plates. and a fan to force cooling air.

“Barrel-type Salmson engine”

-Below we show another logo of the brand and perhaps used in aviation and/or cars.

“Salmson logo”

-From an American publication we have the following photographs, indicating powers but not the models.

“Model A barrel-type”

“It seems to be a C model”

-By comparison with those shown in the main text it seems that it is a C model, also known as “Obus” due to its general shape.

-Although the author notes several differences, so it may be a variant of the main model, modification, prototype, etc.

-An axial type Salmson engine is now offered, with 7 double cylinders (total 14 pistons) and oscillating plates. They were known as the “Obus” (bombshell) type because of their shape similar to ammunition.

-The one in the photo is air cooled and has a fan behind it to force this air which, with deflectors and appropriate ducts, undertakes its mission.

“Salmson Obus (possibly a C type)”

-We have also known a horizontally installed radial engine but without a 90° outlet as the Salmsons in a lowered position usually have. Unless it is the small stem that appears on the left side.

“Salmson ¿300?”

From Appendix 10: Salmson radials, especially those licensed by Canton-Unné from Switzerland, were water cooled. and it had variants as the collaboration with Szydlowski and Planiol, like the SH-18.

-The hoods of the Salmson airplanes were distinguished by their shape. The English call the standardized engine hoods for each make and model “Power Egg”.

““Aircraft with a Salmson engine, clearly””

-In front of the plane a French pilot, with his typical military “Kepi” hat, unmistakable. Returning to the Salmson engine hood, it appears to be complicated in manufacturing.

-Below is an interesting photograph of an engine whose footer describes it as Salmson. Then it must belong to one of the first engines made by the Swiss licensed brand of Canton-Unné. It is revealed by the fact that, being a radial, it has a cylinder precisely in the lower central part, which is not usual in radials because that is where the oil collector from the crankcase usually goes.

-Another detail is the water supply tank at the top.

-That is why it is interesting, the beginning of a brand is usually unknown.

“One of the first 7-cylinders”

- Salmson radial engines were mostly based on the Swiss Canton-Unné patent.

-They are water-cooled, fixed, radial engines, which already makes them different from the common other brands.

“The Salmson 200 CV is a double-row 18-cylinder radial engine”

“200 CV wet sleeves”

-Precisely in this last diagram it is observed that there is no master connecting rod and all the rods are subject to a collar that is on the crankshaft journal, which indicates that the ovals they generate are equal and therefore the compression ratios do not vary between cylinders and a better engine running is assumed.

From Appendix 12: Two new illustrations of two of the brand's engines.

“Salmson 9-cylinder, 75 CV”

“Salmson 9 AD, 40 CV”