Salmson – a brief history.
Famous of course for being the spiritual home of Renault, but before Louis built his factory in Billancourt, an altogether different engineer set up shop here leading to some perhaps unexpected diversions. As with so many Victorian-era small time engineers, Émile Salmson (1858-1917) ran a workshop where he produced steam powered pumps for railway and military applications. Attracting the likeminded Georges Canton and Georg Unné, the company changed name to Émile Salmson & Cie, manufacturing pumps, magnetos and engines.
Further plans would include producing radial aero engines. Investment and excellent results found ES & C at the forefront of French aircraft engine production as the Great War began. At full capacity in Billancourt, some aero engine production migrated to Villeurbanne, near Lyon. This too would include an unsuccessful helicopter.
With hostilities over, priorities altered. Demand for aero engines fell, so typewriters and woodworking lathes would become the company’s mainstay, but the burgeoning private car business was seen as the way forward. Management realised the fastest route to automotive production was through licencing – the English GN marque being chosen and signed up in 1919. The first Salmson-built GN was produced in just ninety days, with that year’s Paris Auto salon adorned with new GN models strategically placed to raise the Salmson profile.
Salmson’s sales director André Lombard sought more performance and higher sales, the catalyst being fellow Parisian based engineer, Émile Petit. In 1922, the aero-engine and car manufacturing entities were split, founding the Société des Moteurs Salmson (SMS).
Introducing Petit’s air-cooled engine to the GN chassis brought approval from the SMS board – however, they insisted upon water cooling. Petit took up the challenge, taking a mere three months to have a production ready unit. This 1086cc liquid-cooled engine had overhead valves – a single pushrod actuating both inlet and exhaust valves – pulling open the inlet then pushing out the spent gas. Petit’s engine was then thrust into the motorsport arena, tackling the brutally tough Swiss Six Day Trial, earning a gold medal. At the inaugural 1923 Le Mans race, the car finished 12th overall[1], winning the 750-1100cc class.
Private entrants took up the racing baton with Salmsons raking in over 500 victories over the years: one notable success being at Brooklands. The company returned to the Circuit de la Sarthe in 1927 with an incredible second and third places, just behind the winning Bentley. Sunday’s racing successes however did not bring Monday morning sales.
The GN car was abandoned as a multitude of Salmsons left the Billancourt plant over the next few years, powered by a new Petit engine design. Believed to be the world’s first production DOHC engine, Salmson’s push toward engineering excellence was badly mistimed. Just as rivals Citroën and Renault began mass production, the onset of the depression left Salmson a somewhat niche product, especially since their clientele remained within the wealthier echelons. More horsepower also equated to heavier taxation, another sales stumbling block.
Petit even delved into building a straight eight engine but only two examples were created as funds began to dry up. Regardless, Salmson ploughed their furrow with a selection of exemplary vehicles that altered little over twenty-five years – the S-series which ran from 1932. Over time, independent suspension, rack and pinion steering and increasingly powerful engines were gradually introduced. These vehicles saw Petit leave SMS with Andre Kow, an art-deco designer taking over design reins.
About this time, efforts were made to bring Salmson to Britain, with the enigmatically named Moteurs Salmson set up in Raynes Park, London. A consortium of investors led by racing driver Howard Martineau took the helm, renaming it British Salmson Aero Engines Ltd, building cars under licence. One primary difference however saw the British version fitted with conventional gearboxes, whereas homegrown affairs used the Cotal system. UK Salmson production would continue until the outbreak of the Second World War.
Meanwhile, back in France and under enemy occupation, the S-series was deemed too complex for use by the French military. The factory was put to general engineering work until it was heavily bombed by the RAF in 1942. Rising from the ashes, production of the S continued in 1946 with a selection of coupé and saloon body styles which garnered the unprepossessing sobriquet, “enlaidissement des carrosseries”[2]. Modern day observers might mellow over the car’s looks, although sightings remain scarce.
Sales never really picked up, just several hundred spaced out over the remaining few years which makes the 1951 reveal of the luxurious Randonnée four door saloon and cabriolet somewhat difficult to justify. Five hundred examples were sold, with an overtly luxurious cabriolet farmed out to coachbuilding concern, Esclassan, widening an already parlous financial situation. Dwindling to sales in double figures, bankruptcy was declared with production managing to limp on until 1957 when the company quietly faded from the car business, and neighbours, Renault took over the site[3].
We conclude our Salmson story however with a twist of fate. In his youth, Jacques Cousteau possessed loftier ideas than his later passion for the deep. Undergoing navy pilot training near Bordeaux during the inter-war years, he could often be found behind the wheel of his father’s 1.5 litre twin cam Salmson S4C Roadster when off-camp. Late for a friend’s wedding, Cousteau, a spirited driver by all accounts, was negotiating the hairpins of the Vosges mountains. The cover of darkness barely hindered progress when unexpectedly the lights failed, the Salmson plunging into a ravine.
His recollections were “of flying through the inky blackness”, awakening the following day in a hospital bed with his left arm broken in five places, his right paralysed. Aviation plans scotched, he took to the water which not only assisted with his recuperation but precipitated his subsequent career change, although it’s unclear if he ever drove with such elan again.
[1] During practice for the 24-hour endurance, Lombard changed the supplier of the car’s electrics, failing to inform Petit. Post-race, where the sister car finished 15th overall, a huge row between Petit and Lombard saw the latter leave the company and racing activities halted for three years to concentrate on road car sales.
[2] Which roughly translates as “disfigurement of bodywork.”
[3] Salmson still exist today. Wilo Salmson France SAS are a multinational company still producing pump equipment.
Data Sources: amicale-salmson.com, motor-car.net, uniquecarandparts.com, velocetoday.com.
Driven To Write 
Andrew, thank you for reminding me of this car, and adding some details I was unaware of. In the age before classics were invented, a schoolmate told me that his father had a British Salmson. Apart from the obvious Bentleys and Bugattis, my motoring history was sketchy and this meant nothing to me, though he seemed very proud of it. Of course when this crass little schoolboy finally saw it, it seemed like just another old banger. I wish I’d known more and had the sense to ask for a close look, or better still a drive as a passenger, so that I could now share something more than my regrets.
And this, with a rather satisfying ‘oily rag’ patina and inviting interior, could be yours for €9,500.
https://www.lesanciennes.com/annonce/salmson-s4-61-1949-a314131
Interesting article Andrew.
In the early 70’s I could drive a late 30’s saloon that belonged to a friend of mine who was a vintage cars collector. It had a DOHC 2.3 liter engine with a Cotal gearbox. Gosh, that was fun! Even though it was a rather heavy four-door with an antiquated suspension technology, its extremely punchy engine and the fantastic Cotal gearbox made the driving experience very involving. I had already driven modern cars like the Citroën DS and the Renault R16 but they were boring or even unpleasant like the latter.
Why the heck, Citroën who was never able to design a correct engine, didn’t buy Salmson and Cotal when they went bankrupt just to acquire the engine and the gearbox? That’s what the DS deserved.
In the early 60’s a company called SFERMA (Société française d’entretien et de réparation aéronautique) commissionned the development of a 1600cc and a 2000cc engines upon the Salmson technology. They were quite effective. They were to be used by Facel-Vega but backrupcy hit this one too. Only prototypes were ever built. Citroën would have been were well advised to buy the license.
The Salmson engine and the Cotal gearbox proved extremely reliable even though they were cutting-edge technology in the 30’s. My friend told me that it needed only basic maintenance and that 4 decades later there was never an issue. Most vintage luxury car makers like Delahaye and Delage used the Cotal too.
Gear shifting was practically instantaneous and you didn’t need to use the clutch pedal (although it’s now recommended by the collectors to do so when shifting because it may be hard on the engine and the transmission). Clutching was necessary only when pulling away.
So it was both a pretty easy manipulation (more so than the DS) and a fun driving experience. And it went down the drain. Sigh.
Nick
I forgot to mention that the Cotal gear shifter was dubbed “le pot de moutarde” (the mustard pot) because of its resemblance to the pots found in restaurants that had a wooden spoon with a small ball on top.
See:
https://www.conceptcarz.com/view/photo/2989245,15266,1/1938-Delage-D6-70_photo.aspx
This one is elegantly painted in white. I wonder if it’s original. Most were just bare aluminum. Some had a fancy top like a dice.
Nicolas. That’s a tantalising suggestion about Citroen taking on the Sampson twin-cam for the DS. Naturally, pride would never have allowed them to. Still …
Though I’ve never used one, from descriptions I have long thought that the minimal inputs of a Cotal box would have been far more in keeping in the DS and its spiritual successors than the more prosaic manuals used – though the 4/5 speed DS box was no bad thing in itself.
And yet Citroën commissionned Maseratti to design the engine for the SM. The Salmson or the SFERMA engines would have certainly been more reliable and probably just as powerful. Being in-line fours they were certainly cheaper to manufacture. The Salmson had no belt nor chain timing drive but a vertical shaft. I bet it was fail safe.
To me the Cotal gearbox was a marvel. I am sure it would be still relevant today. The funny thing is that it had no integrated reverse gear but an inverter. Therefore you had four gears in each direction. Therefore to go backward you had to put the inverter in reverse and choose a gear… any of them.
Citroën and particularly its president of the time Pierre Bercot were certainly paragons of corporate hubris.
Too bad Salmson with the other French premium and luxury car makers were all shut down in the 50’s. Sigh.
If you tell me again how to post pics on this forum I will send some.
Nick
A 4 speed reverse! I just gets better and better. I have a great deal of respect for Bercot, but I suspect he was a snob (at least an intellectual one) and considered Maserati as far more exotic than he would Salmson. Not that there was anything wrong with the Alfieri V6 – at least once the things that were wrong were put right.
Here’s DTW’s instruction on embedding photos.
I am using a Mac and it seems there is no version of Imgur for it.
You can see pictures of the engine and the gearbox here:
1. At the rear end of the engine you can (hardly) see in the cutaway the timing mechanism with its vertical shaft and its helical gears in a crossed configuration.
2. The clutch.
3. The inverter with its small lever. It has 2 positions: forward and reverse.
4. The cylindrical thing is the gearbox. Its diameter is rather big but it’s quite short. It’s a planetary, electro-magnetically actuated system.
Another view:
You can see photos of the restoration of a 1950 model here:
https://www.techni-tacot.com/restauration-en-cours/restauration-salmson-s4-61-1950/
I looks pretty much like the one I drove.
I am not fond of that style of cars and I find Salmsons particularly bland. It’ just OK for me.
Nick
I remember a friend having a pre-war MG PA or PB with a shaft driven OHC for its’ (Morris ?) engine. Of course the shaft wasn’t just a shaft – it was the core of the dynamo.
Nick. Imgur is online http://www.imgur. com , so your device shouldn’t make a difference. Anyway you seem to have got the photos up. The engine and gearbox seem to be a satisfyingly solid piece of (over)engineering. Which makes me suspect that it could never have been an economically sensible proposition for Citroen – not that that would have stopped them.
Yes, the S6-61 is bland, but satisfyingly bland to my eyes, though it won’t be going into my fantasy garage. Interestingly from the restauration photos is the small forest involved in the car’s construction and the fact that, Lancia like, it does without a B pillar.
You can’t imagine how asthmatic the DS engine was in the 50’s and 60’s. My father had his first one in the late 50’s when I was about 15. I could drive it when I got my driving license: I floored the throttle and… nothing happened until a sluggish movement told me we were on our way. Very frustrating.
The Salmson engine would have made an attractive proposition for high-end DS models while the IDs (the poor man’s DS) would have kept the old pushrod 11CV’s engine.
The Salmson derived SFERMA engine would have been even better:
(I dowloaded these pictures years ago and I couldn’t find where. So I can’t tell the copyright).
It’s obviously a rather sporty thing:
• Almost hemi head.
• Double ignition.
• Double carburator.
• Oversquare. Bore: 94mm, stroke: 75mm.
• 140hp at 7500rpm.
But it could certainly be detuned.
How many missed opportunities and waste of efforts!
Nick
PS. In my preceding post i just pasted the link to images and they got displayed. It’s actually the same thing with Imgur.
Was 10 hp enough to move a car? Could someone express the experience of driving these cars?
I wrote a post this afternoon and it’s not in line. Do I have to redo it?
Nick
Hi Nick. Apologies: because your comment had more than two images embedded, WordPress automatically sends it to the moderation queue. Eóin is currently on vacation and I am still trying to get things in order after our house move, so only recently noticed your comment. It’s now approved.
OK, Daniel, thanks.
If people need explanations about this restoration I can do some translation (don’t expect me to translate it all though ;-)).
It’s interesting. I learned a lot of details in particular about the engine. It has quite a few archaic features along with many modern ones. In the 50’s it was cutting-edge. I had been wondering why the block is in 2 parts: one for the cylinders and one for the cranckcase. It’s because it’s impossible to insert the piston+connecting rods from the top because the connecting rod heads are too big for the cylinders. So you had to do the insertion piston first from the bottom of the cylinder block then assemble the latter with the cranckcase. Labor cost was not an issue at that time.
Yet I am still frustrated I couldn’t learn more about the Cotal gearbox. Along the years I could gather some informations and blueprints but I never could find shots of the components or of a cutaway. In an other restoration of a Ford Vedette of the 50’s the repairman says the gearbox needed no maintenance at all.
Nick
Hello gpant. The 10HP, 7CV etc horsepower references are various theoretical fiscal figures, mostly based on formulae based on fixed parameters produced in the early 20th Century. They differed from nation to nation, but the British RAC rating, for example, used the diameter of the cylinder and the number of cylinders, but took no note of the stroke (hence the proliferation of tax saving long stroke engines in the UK at the time). When they were produced they were maybe vaguely in line with actual engine power, but as engines improved they soon became irrelevant. So by the 30s, the Citroen Traction known as the 11CV in France, was the 15HP in the UK, but probably developed around 55hp which made it perfectly fine to drive.
Nick. Oh yes, I’m totally in agreement about the original ID/DS engines. Having looked in wonder at Deeses floating past, when I was finally driven in one as a schoolboy passenger I was hugely disappointed at the agricultural sounding engine, and this was a ’68 car, so it would have had the heavily revised (new, if you prefer) 5 bearing engine from 1965. Admittedly, Citroen did relative wonders with the engine to power the fuel-injected DS23 and then even more so when it was taken over for the CX, but it was never smooth.
Good afternoon all. Many thanks to Nicolas and Bristow for the excellent supportive information. Nicolas, you could’ve done an article on the engine and gearbox alone…us poor authors are allowed only around a thousand words.
And under 10k for that 1949 model? Tempting but my schoolboy French may become problematic. But at least I’d have plenty of mechanical information, here.
I guess all mechanical nerds, when they see the pictures of such an engine, with a couple of supplementary information like the type of timing mechanism, just do some mental reverse-ingeneering. The Salmson one is pretty straighforward: you could almost tell the angles of the valves.
On the other hand the Cotal gearbox is a black box (a cylindrical one for that matter). Knowing it’s an epicycloidal, electromagnetically actuated type isn’t giving you a clue. My friend had shown me the engine but of course the gearbox was invisible and anyway there is nothing to see on it. It remained an itch for decades. I finally got the clue thanks to very confusing documents. There is very little on it on the net.
Yet it was rather popular until the 50’s: it was standard on premium brands like Salmson, Delahaye, Delage, Hotchkiss, etc., and even Peugeot would offer it as an option.
It would certainly deserve an article but the graphics I found are of very bad quality.
Nick
Some more shots of the engine with a better view of the timing mechanism:
Nick
I just got the information about why there is so little documentation on the Cotal geaboxes: the boxes were sealed in the factory, MAAG, the manufacturer, would provide no technical data and no parts, and for repairs they had to be sent to the company. Fortunately they were quite reliable so it was hardly ever needed. Yet, nowadays, they do suffer from old age and collectors have to manage to reshuffle them. I read that a workshop charges €12 000 for a complete overhaul!
The Salmson owners association has some documentation reserved to its members. Membership is €60.
I had found long ago an image and I had to struggle to find it again because its name had been modified:
I have a collection of such views that are not self-explanatory at all. One needs a textbook to understand. The file name is “Cotal electrically-activated epicyclic gearbox (Autocar Handbook, 13th ed, 1935).jpg”. It’s name reveals its origin so if anyone could lay his hand this handbook and share it it would be nice.
Since it’s in the Wikimedia Commons I looked which Wikipedia article it was in. I had to struggle again and eventually found it : it used be in and was removed from the page: “Talk:Preselector gearbox”, https://en.wikipedia.org/wiki/Talk%3APreselector_gearbox#File:Cotal_electrically-activated_epicyclic_gearbox_(Autocar_Handbook,_13th_ed,_1935).jpg_Nominated_for_Deletion.
BTW I saw several times that the Cotal gearbox is of the preselector type comparable to the Wilson gearbox. It’s wrong: with the Cotal the speed is engaged as soon as selected and when shifting gears you don’t need to declutch even though you can as in a standard gearbox. IMHO it rivals with the dual-clutch type in terms of shifting speed.
It made the cars it equipped like the Salmsons, the Delahayes, etc., extremely pleasant to drive, especially when mated with a powerful engine.
Nick