A correspondent who has done me the honour of reading a recent article in this series in which I referred to the discussions in 1908 of the representatives of the national automobile clubs about the “Gobron question,” suggests that I might well have prefaced this description with a rather fuller account of the Gobron-Brillie engine which gave rise to these discussions. As a matter of fact, I tended as it was to exceed my allotted space on that occasion, but as I always try to pander to critics, I will return to the charge, and the Gobron-Brillie, now.
Among present-day motorists, the name, it is true, is scarcely one to conjure with, but in 1907, when M Pierre Souvestre wrote his Histoire de l’Automobile, he included it among those of the dozen marques which he regarded as the prime architects of the fame of the French industry. Its actual origin is lost, for me, in the mists of antiquity, but it would seem that the main features of the design which made the Gobron-Brillie famous, were patented in 1897. These, of course. included the opposed-piston engine, but it seems highly probable that in this respect its designers were anticipated by Mr George Johnston, of Arrol-Johnston fame. Before the end of 1895, this gentleman was reported as running in the streets of Glasgow what may be described as a horseless dogcart, as it is stated that “in appearance it resembles a four-wheeled dogcart without the shafts.” Later editions of this machine were fitted with a horizontal two-cylinder engine, having two pistons in each cylinder operating a single crankshaft by means of cross-heads and connecting-rods, and if one may assume that a similar motor powered the first dogcart of 1895, Mr Johnston’s claim to have introduced the opposed-piston engine into automobile practice would be hard to refute.
In this case no very great importance would perhaps attach to the question of who was the originator of what came to be generally known in later years as the Gobron motor. Mr Worby Beaumont seems to discount the idea that the bulk of the credit should in fact be given to the first of the partners, as he refers to it consistently as the Brillie engine. On the other hand, M Lavergne, while he is non-committal about what he calls the Gobron and Brillie motor, attributes specifically to Brillie only the carburetter and the car’s steering gear. Yet another authority asserts that the “inventor” of the Gobron-Brillie was M Roland, who otherwise appears as a driver of these cars in the early races. No one seems to give much credit to M Gobron for the “Gobron” engine, and perhaps he owes his lion’s share of the fame in the matter to his having outlasted his colleagues. In 1908 it was he, it may be remembered, who spoke in favour of “his” engine to the delegates of the automobile clubs, so that clearly he was still interested at that date in opposed pistons. On the other hand, although some years later the company was still known as the Societe des Automobiles Gobron-Brillie, I find M Eugene Bribe advertising in 1907 the fact that the Societe des Automobiles Eugene Bribe were at that time the sole suppliers of omnibuses to the Paris Compagnie Generale, and that these vehicles were made in the artillery works of MM Schneider of le Havre. If this was the same M Brillie it seems that by then he may have parted company with M Gobron, and left him to go down to posterity as the apostle of opposed pistons. At any rate, until it is disproved I prefer this theory to the suggestion, which I consider almost flippant, that M Brillie’s lesser fame is merely due to the difficulty of pronouncing his name. After all, it was Levassor who was primarily responsible for his firm’s pioneering work in the development of the motor car, and Levassor is quite an easy name to pronounce. For all that it is a name far less well known than Panhard’s, and, outside France, nobody can pronounce Panhard at all.
However, to return to the Gobron-Brillie car: when it made its first appearance in this country, which was at the Automobile Club’s Richmond Show in 1899, it created so much interest that, although it did not take part in the Trials, it was awarded a silver medal “for novelty and ingenuity of the parts.” This is hardly surprising, for it undoubtedly bristled with ingenious novelties. In the first place the engine had two vertical cylinders, but in each cylinder there were two pistons, of which the lower ones moved up and down together on the same long crankpin. The connecting-rods of the two upper pistons were joined by a crosshead, at either end of which was another connecting-rod, and these latter ran right down the ends of the engine and were coupled to cranks at 180 degrees to those of the lower pistons. It seems fairly obvious that, if it was to work satisfactorily, an engine designed on these lines must be made with a high degree of precision. “This crosshead,” says Mr Beaumont, “is a rigid casting, which maintains the parallelism of movement of the parts connected to it, including the two [long] connecting-rods, which are firmly secured into its ends in the same plane as the two short connecting-rods. So long therefore as the two [long connecting] rods are of precisely the same length [my italics] there will be no cross stresses on the [upper] pistons, even when the explosive combustion occurs in the space of one cylinder only.” If they were not of precisely the same length, no doubt the most horrible things would happen.
In 1908, when the “Gobron question” was at its height, the chief advantage of this arrangement seemed to be that for a given crankshaft speed and a given combined stroke of the two pistons in each cylinder, piston speed was at any rate nearly halved compared with that obtaining in a normal engine. (It was not necessarily exactly halved for a reason that will become apparent in a moment.) It seems tolerably clear, however, that this consideration hardly entered into the calculations of the designers of the original Gobron-Brillie engine at all : its normal speed was only 700 revolutions a minute, and its combined piston stroke was, no greater than the stroke of each single piston in such contemporary engines as the Amedee Bollee and Cannstatt Daimler which ran at about the same crankshaft speed. Nor would it seem that the designers were under any illusion that by doubling the number of pistons they were going to double, or, indeed, no more than perhaps fractionally increase, the power output. “The total expansion,” ‘says Mr Beaumont, “is, of course, the same as with the ordinary arrangement, only the rate at which expansion is effected is doubled, and this should give higher duty”—whatever exactly that may mean. No, the object of the Gobron-Brillie exercise was undoubtedly to improve the balance of a two-cylinder engine, and in this endeavour it obviously succeeded.
The matter, however, was a little more complicated than Mr Beaumont seems to have appreciated—or at least explained. “The motor cylinders,” he remarks of the 6-hp engine he is describing, “are 80 mm (3.15 in) in diameter and the same in stroke.” This is a rather cryptic saying, as it is not quite clear whether he means that the stroke of each piston, or the combined stroke of the pair in each cylinder, was equal to 80 mm; and I was astonished to find by admittedly rather crude measurement of his meticulous drawing, that the distance, between the centre lines of two crankpins at 180 degrees to each other, with the pistons at top and bottom dead centres respectively, did not appear to be equal either to the bore or to half of it. M Lavergne, however, supplies the answer to this conundrum. The coupling of the upper pistons, comprising the crosshead, he explains, is heavier than that of the lower pistons, but in return the throw of their cranks is smaller than the throw of the lower pistons’ cranks, “and the difference is calculated so that the strains of the two sets of pistons perfectly equilibrate each other. All the motor vibrations appear to be overcome.”
I will leave it to my more mechanically minded readers to assume a reasonable weight for the crosshead, to estimate the extra weight of the upper pistons’ short and long connecting-rods, and then to calculate the relative strokes of the upper and nether pistons which would “perfectly equilibrate” the strains. I should think that it would keep them quiet for some time. Meanwhile I will disclose that my crude measurements of Mr. Beaumont’s drawing suggest that the stroke of the lower pistons may well have been the same as the bore, viz 80 mm, but that the stroke of the upper pistons may have been no more than say 65 mm. It is rather interesting to compare this result with the known dimensions of the 8-hp Gobron-Brillie engine of 1901, which are given as 110 by 200 mm, and it is at least tempting to translate these figures as 110 mm, bore by 110 mm, stroke of lower pistons by 90 mm, stroke of upper pistons, because 110 is to 90 in very nearly the same ratio as 80 is to 65. When, however, we come to later Gobron-Brillie engines it is apparent that there is a distinct tendency, in those where I have been able to spot the dimensions, for the combined stroke to be exactly twice the bore. Thus in 1909 there was a 10-hp. two-cylinder of 90 by 180 mm, and in 1910 a 20-hp four-cylinder of the same dimensions; in 1913 there was a 12-hp four-cylinder of 75 by 150 mm, and a 16-hp of 80 by 160 mm, and in 1914 a 22-hp of 100 by 200 mm. From this it is at least tempting to conjecture that by this period Gobron-Brillie had found some method of “perfectly equilibrating” the crosshead other than by variation of the stroke of the two pistons, as for instance by counterweights on the crankshaft. From this assumption one may work backwards, at the risk of building a fantastic house of cards, and notice that the 110 by 200 mm two-cylinder engine of 1901 was followed in 1903 by a four cylinder with dimensions of 140 by 220 mm. The latter’s stroke was twice the bore of the former, and it is tempting to believe that the four cylinder engine already used a revised edition of the two-cylinder crankshaft, with equal throws for both sets of pistons. In that case the stroke of neither set of pistons exceeded 110 mm, and the piston speed was exactly halved compared with that of a normal four-cylinder engine with the same bore and the same capacity, running at the same crankshaft speed.
To return to the 6-hp model of 1899, the designer, whoever he may have been, had only succeeded, as a result of all his ingenuity, in producing an engine with a crankshaft the same shape as that of a four-cylinder, and I suppose that the results as far as vibration was concerned were not very different. As Panhard et Levassor had been using a four-cylinder engine at least since 1896, this alternative, and one would have thought simpler solution of the problem must have presented itself to the Gobron-Brillie designer when he took out his patents in 1897, and one may wonder in consequence why his opposed pistons still appeared so attractive. The answer, I think apart from the fact that people, fortunately, like doing ingenious things—may well have been that, like most nineteenth-century designers with the shining exception of Levassor, he was attracted by the idea of running his crankshaft in the same plane as the roadwheels. This inolved setting the engine athwart the car, a position in which excessive length is apt to be awkward, and the Gobron-Brlllie design prodered an engine which was little more than half as long as a four-cylinder of equal bore. What it saved in length it lost to some extent in height, but as it was placed at the back of the car, underneath the seat, this was of no great consequence. Admittedly this placed it between the back wheels, so that it was impossible to get a starting-handle direct onto the end of the crankshaft, but this difficulty was solved, at the expense of one pair of bevels, by running a shaft at right angles to the back of the car. On the other end of the crankshaft was a large straight pinion, gearing with another, forward of it, on the clutch shaft, there was an ordinary sliding-pinion gearbox, and final drive was by side chains.
There was nothing very remarkable about the valves, which were in a pocket at the side of the cylinders, with the automatic inlet valve directly above the exhaust valve. Contemporaries, however, were keenly interested in the carburetter—or what did duty for it. “The carburetter, as it is usually called,” says Mr Beaumont, from which I conclude that he did not consider it was one, “is, in fact, a rotative petrol measured feed apparatus and atomiser.” It was certainly very complicated, but what it did, as far as I can make out, was to feed metered quantities of liquid fuel, by means of a sort of multiple bucket device, into the inlet pipe, where, and in the combustion chamber itself, it was mixed with air. As it left this process to take place elsewhere the device was not, I suppose, strictly speaking a carburetter. “The amount of petrol spirit for each cylinder charge,” says M Lavergne, “is just what is required for uniform carbutetting, complete combustion, and the avoidance of odour. This, at least,” he adds cautiously, “was the inventor’s object, and time will tell whether he has fully succeeded.” I am afraid that it did—in a negative sense; at least before very long the Brillie petrol meter seems to have been abandoned in favour of a genuine carburetter.
The remaining really remarkable feature of the original Gobron-Brillie car was the steering-gear, which worked on what was called the epicycloidal principle. Like most other things about this design it was exceedingly complicated, and the fact that, although situated on the right-hand side of the car, the direct control was to the left-hand front wheel, by means of an oblique push-and-pull rod, was, as far as I know, merely incidental to the scheme, the main object of which was to provoke varying degrees of deflection in the front wheels according to where they were pointing. Thus when the wheels were straight or very nearly, a given movement of the steering wheel produced very little effect on them; but as they approached either lock, the effect became increasingly marked. On the face of it, this steering would, I should have thought, have been horrid : while the car was running straight it must have felt so unresponsive as to tempt the driver to give it a sharp yank, whereupon, one would snppoee, it flung onto full lock like nobody’s business. The idea behind it, as far as I can make out, was to provide very irreversible steering at speed on the straight, which should nevertheless not be too low-geared for manoeuvring; and as one hears of no complaints about Gobron-Brillie cars suddenly dashing off the road with next best thing to no warning, it may have worked better in practice than one might imagine.
The sponsors of the 6-hp car which appeared at Richmond in 1899 may have been content to forgo the Trials and rely on novelty and ingenuity in order to secure a silver medal, but obviously if the car was to make any sort of a name for itself in France it had got to be raced, and, sure enough, the next year Brillie turned up at the start of the big race of 1900, Paris-Toulouse-Paris, with a Gobron-Brillie rated at 18 hp. In after years when the manufacturers supplied Gerald Rose with the particulars of all their later racing cars, they seemed to have forgotten all about this one, and one can only surmise that it was a much enlarged version of the 6-hp of 1899. With a weight of 1,400 kgms it was the heaviest car in the race, and it does not seem to have been very fast, as the outward journey of 421 miles to Toulouse, which had to be done in a single stage, took it less than half an hour under the full twenty-four. On the return journey, which was spread over two days, it was a little quicker, its running time being just under 20 hours, and it finished last of the big cars at an average of 19.3 mph. Nevertheless it had successfully completed the whole trip of 837 miles, and after that no one could say that the Gobron-Brillie system did not work.
Among those who were impreseed were apparently the directors of the Societe Nanccenne, who promptly acquired a licence to build cars on the same system. Moreover, those responsible for the Gobron Brillié design seem to have realised that if they were to do any good in racing, weight must be drastically reduced, and at the start of Paris-Berlin in June 1901. they appeared with some very much lighter vehicles than the 1,100-kg machine of 1900. Gobron contented himself with driving a car in the tourist section of the great international event, but Brillie started in the “heavy” car division of the race itself on a Naccenne rated at 10 hp, and weighing only 725 kgms. Nor was this all, or, indeed, half the story, for another 10-hp Nanccenne, driven by Ponton d’Amecourt, weighed only 640 kgms and was thus able to run in the light car section, Where the weight limit was 650 kgms, and in which Roland and Dernier drove 8-hp Gobron-Brillies weighing 640 and 645 kgms, respectively, and Rigolly a third car which, although rated at 12-hp, weighed only 600 kgms. As a matter of fact, in spite of these various ratings it seems probable that all the Gobron-Brillie and Nanccenne cars in the race used the same engine, having two cylinder with a bore of 110 mm, a combined stroke of 200 mm and a capacity of 3,601 cc.
Whatever was the exact power of his engine, it was obvious that Brillie could not do much in the heavy class against the 60-hp Mors and 40-hp Panherds, but at least he seems to have run quite consistently and finished the full 687 miles at 23.9 mph. In the light car class, Ponton d’Amecourt fell out on the first day, but the performance of the genuine Gobron-Brillies was much more impressive. The class was dominated by the Panhards and the Darracqs, but behind their leading representatives and a Peugeot, Roland came in in seventh place at 27.7 mph, with Dernier tenth and Rigolly thirteenth. No one else in the class except Panhard managed to finish with as many as three cars.
The French Government at this time was exceedingly keen to encourage the use of industrial alcohol, made from home-grown sugar beet, as a substitute for imported petrol, and Gobron-Brillie were only too willing to pander to this enthusiasm as it seems that this fuel suited their engine particularly well, although whether on account of the metering paracarburetter, or, as seems more probable, as a welcome assistance in keeping an opposed piston engine cool, I am not sure. In any case, when the Circuit du Nord race was organised in May 1902, for cars using alcohol fuel only, Gobron-Brillie promptly entered three light cars, to be driven by Rigolly, Berrue and Achille Fournier. Although now rated at 16 hp, they seem still to have used the 110 by 200-mm engine as in 1901, but the firm’s racing experience, short as it was, had already taught an important lesson, and the engine was now placed at the front of the car, with its axis along instead of across the chassis. Apart from this it looks as if a good deal more power must by now have been extracted from the engine, as although two of the Gobron-Brillies fell out in the course of the race, Rigolly on the remaining one finished third in the Class, behind a Darracq and a Panhard.
By now the Gobron-Brillie system had another admirer, in the shape of the Belgian Nagant concern, and in the great race of the year, Paris-Vienna, there was a tremendous turn-out, consisting of five Gobron-Brillies, driven by Rigolly, Berrue, Achille Fournier, Koechlin and Duray, and two Gobron-Nagants driven by Conrad and Dernier. Although the engine dimensions remained unchanged, all were now rated at 18 hp, but in the Gobron-Nagants the engines were still at the back across the frames. As an exception to prove the rule, moreover, it was one of the latter which put up the best performance, Dernier’s car finishing eleventh in the class at 29.6 mph, all the rest of the two teams duly reaching Vienna, however, with the exception of Arthur Duray.
In view of Gobron-Brillies Belgian connections it was hardly surprising that they entered for the Circuit des Ardennes race at the end of July. Roland and Rigolly driving French-built cars and Dernier and Conrad the Nagants. This time the latter seemed relatively slow, and Roland hit the kerb and broke a wheel, but Rigolly soon showed that he had the heels of all his rivals, and proceeded to win the light car class at 46.3 mph for the 318 miles. Gobron-Brillie had arrived.
In order to achieve real fame in French motoring circles, however, it was necessary, as even such light-car addicts as Renault and Darracq were soon to find out, to run with the heavy racing metal, and during the winter of 1902-3 Gobron-Brillie laid their plans to do so. The result was a monster racer, now with four cylinders. the bore being 140 mm, the combined stroke 220 mm and the capacity 13,547 cc. By the beginning of April it was finished, and when it arrived in the South of France for the Nice Meeting created such a furore that even the usually somewhat matter-of-fact correspondent to the Autocar was really excited. “What is known as the 120-hp Gobron-Brillie car made a sensational entry into Nice on Thursday fortnight,” he wrote. “Just imagine a vehicle more than 13 feet in length and having a wheelbase of 9.84 feet and a huge semi-circular bonnet tapering from the dashboard to a point in front, giving it the appearance of half a shell of some monster gun. The frame is made up of tubes girder fashion .. . The only things recognisable about the engine are the two vertical cylinders and four pistons” -and, if I may interrupt, these were just what evidently were not recognisable, as what looked like them were really two blocks, each of two cylinders, and altogether there were eight pistons-“enclosed in square vertical cases forming part of the engine bed. All the rest has been changed. Both the induction and the exhaust valves are operated mechanically by the same camshaft. The old positive carburetter has been replaced by one of the constant level type and the gases are conveyed to the other side of the engine by a pipe passing between the two [blocks of] cylinders. This pipe is jacketed, so as to be warmed by the water from the engine, this arrangement being particularly necessary in the event of its running with alcohol. The throttling valve is in the pipe just in front of the carburetter. The length of the engine is about 4 ft and the height is probably 3 ft 6 in It develops from 100 to 110 h.p.
“With such a huge engine it has been found necessary to adopt a system of double friction clutch, allowing the engine to be put into gear gradually. The variable speed gear is of the usual type, with direct drive to the countershaft on the top speed. The car was in charge of Rigolly, who informed us that it had only just been turned out from the works, and no test of its speed capabilities had yet been made, so that it is impossible to give an idea of what this wonderful vehicle can do. When being driven along the Promenade des Anglais we were particularly struck with the smoothness of running of this huge car. Rigolly appeared to have it under perfect control and drove it at any speed up to the legal limit, the noise being far less than in certain cars fitted with engines of two-thirds the power. The motor has to be started by a long straight lever, which brings the gases to compression by quarter turns, and then a good deal of knack seems to be necessary to start the engine with the text turn.”
Presumably it had been intended to run it in the mile sprint on the Promenade des Anglais, which was a regular feature of the Nice Meeting. but owing to the death of Count Zborowski at the start of the la Turbie hill-climb, the whole of the rest of the 1903 meeting was abandoned. and the opportunity, therefore, never presented itself. “It is a pity that no opportunity has yet been given of testing this car,” lamented the Autocar, “for its appearance conveys a wonderful impression of speed and it would go quite as fast as human skill could drive it.”
However by May, when Paris-Madrid was run, three 110-hp cars were ready and were driven by Rigolly, Duray and Koechlin. They did not particularly distinguish themselves, the fastest of them averaging only just over 44 mph, and they did no better in the Ardennes race, where, however, Tavenaux on a 40-hp two-cylinder Gobron-Brillie was second in the light car class at 45.9 mph. It was however in the sprint races at the end of the season that the big Gobron-Brillies really came into their own. In July there were flying kilometre trials at Ostend, when Rigolly made easily the best time with a speed of 83.4 mph, and Duray was the runner-up; and they made fastest and second fastest time of the day in the Laffrey hill-climb in August, at Chateau-Thierry in October and at Gaillon in November. Back at Ostend again in 1904, Rigolly improved his speed for the flying kilometre to no less than 103.5 mph.
They were obviously at that time the fastest cars over a short distance of any in existence, but in the long races they were never successful, although in the Ardennes in 1904 Rigolly was fourth, at 54.8 mph. After that the other two cars seem to have disappeared, but Rigolly’s wonderful old 1903 racer went on year after year, running in the French Eliminating Trials of 1905 and the Grands Prix of 1906 and 1907, always able to keep well up with more modern cars when it was running, sometimes finishing but more often going out with a leaking radiator. Only the bore limit imposed in 1908 and the decision of the authorities that it really had not four but eight cylinders stopped it running in the Grand Prix. That gave rise to the “Gobron question”, and that, as you might say, is where we came in.