Thursday, May 27, 2010

The Triplane: A Curiously English Contraption

When a chappie calls to mind a triplane, it is likely that the first image to be conjured is the gaudy, all-red affair of Manfred Freiherr von Richthofen, the Hun flying ace who used the machine to such deadly effect over the skies of France. Indeed, the Teutonic association with the triplane is so strong, that it might shock the modern reading public to learn that triplanes are not German innovations. Rather, they are wholly English. For it was in England that the machine was first devised, in England that it was refined, and in England that it first went to war.

The very first triplane was constructed in 1868, by Mr. John Stringfellow, a charter member of the Royal Aeronautical Society. The machine was powered by means of an exceptionally light steam engine. While only a model, the triplane could nonetheless leave the ground and fly for short distances under its own power. Further, the design of that triplane would have a great influence on later multi-plane machines.

As some of my gentle readers might recall, Mr. Stringfellow's triplane was put on public display by the Royal Aeronautical Society in the Crystal Palace in 1868. There, it amazed onlookers, eager to glimpse the future of transportation. Gentlemen and ladies alike marveled at its unique and innovative appearance, and no doubt the more technically-minded fellows were eager to examine its steam engine and the careful construction of its flight surfaces. The following sketch depicts the exhibition as it is fondly recalled by those who experienced it.

But it was some years before the triplane reappeared in the history of aviation. It wasn't until forty years after the Crystal Palace exhibition that Mr. A.V. Roe, founder of A.V. Roe and Company (the reputable aeronautical firm later to be known to the world as Avro), created a working triplane that was capable of carrying a man aloft.

The Avro Triplane was, at its time, the only triplane being produced anywhere in the world. Further, it was the first machine to combine the aerodynamic qualities of the monoplane fuselage, with the superior lift of the multiplane configuration. Heretofore, multiplane machines had been designed after those of Messrs. Wright and Farman. The Avro triplane represented a leap forward in the business of aeronautics, for soon all multiplane machines would utilize this configuration.

The control configuration of the Avro Triplane is more or less conventional. A control column coupled with a steering wheel control the elevators and the wing-warping, whilst a rudder bar controls movement in the yaw axis. The bottom-most plane of the machine is shorter than the other two, and it is this plane that is warped in order to effect the rolling movement necessary for banking the machine.

Flight magazine has provided your humble correspondent with a detailed sketch of the Avro Triplane, for those enthusiasts who wish to build one themselves, or for the budding young aeronaut who wishes to construct models of the machine.

But the evolution of the triplane, to borrow a term from Mr. Darwin's infamous work, did not cease in England. While the triplane fell out of favor with the start of the war, it wasn't long before the most brilliant aeroplane designer of his time, Mr. Thomas Sopwith, produced a triplane of his own.

The Sopwith Triplane was flown exclusively by His Majesty's Royal Naval Air Service. It began its career during the month of Bloody April, a time when Hun attacks were sweeping the Royal Flying Corps from the skies. The superiority of the new Albatross and Pfalz scouts caused the RFC its greatest losses of the war. But the same could not be said for the RNAS and their new Sopwith Triplane. The following account, taken directly from men on the ground who witnessed the action, demonstrates not only the triplane's superiority in combat, but also the superior spirit of the English aviator.

At 6:45 p.m. on April 7th, 1917, a Sopwith Triplane, working alone, attacked eleven hostile machines, almost all Albatross scouts, N.E. of Arras. He completely outclassed the whole patrol of hostile machines, diving through them and climbing above them. One Albatross scout, painted red, which had been particularly noticed by this section, dived on him and passed him. The Sopwith dived on him and then easily climbed again above the whole patrol, drawing them all the time towards the anti-aircraft guns. As soon as they were within range, the anti-aircraft guns opened fire on the patrol, which turned eastward, and the Sopwith returned safely. The officers who witnessed the combat report that the manoeuvering of the Sopwith Triplane completely outclassed the Albatross scout.

Indeed, the Sopwith machine was far superior to the biplane designs currently favored by all major powers during the war. Its rate of climb was noted, even amongst Boche reports, to be far beyond that of its contemporaries. Its maneuverability was exceptional. The only area where it lacked was in its speed in the dive, owing to the increased drag caused by the third plane. The following sketch gives one a sense of the clean, elegant lines that characterized Sopwith scouts generally, and the triplane in particular.

The Germans would not admit publicly to the superiority of the Sopwith machine. The reports they sent to their soldiers on the front questioned its strength and maneuverability, stating:

(The Sopwith) far as possible avoids any excessive demands upon itself, for it breaks up easily. ...after an unsuccessful attack, (the Sopwith) generally avoids a battle of turns.

My gentle readers are, no doubt, aware that the Boche are absolutely not to be trusted under any circumstances, least of all where the superiority of the English aviator is concerned. However, one need not belabor the point. The actions of the Hun after the introduction of the Sopwith Triplane make the reality of the situation clear enough.

The Boche, you see, whilst a generally humorless and cold race, are nonetheless eminently practical in military matters. Publicly, they may have denied Mr. Sopwith his due, as the designer of a brilliant new sort of fighting scout, but privately, they coveted the machine for themselves. Your humble correspondent, at great personal risk, has obtained definitive proof of the Germans' desperate attempts to copy English ingenuity. Here is a secret sketch, created by the Hun, analyzing the characteristics of a captured Sopwith machine.

In the same, secret, documents, the Germans have perjured themselves, stating that the Sopwith triplane, owing to its exceptionally light wing-loading, is an extremely fast scout, and further that it is possessed of a very high rate of climb.

The greatest proof of all, however, can be found in the actions of the German aircraft designers. It has been said, and not without justice, that imitation is the sincerest form of flattery. If such is the case, then one wonders if perhaps Messrs. R. Schubert, A. Fokker, J. von Berg, and B. Meyer, will not be courting Mr. Sopwith in the near future. All of these designers, and more, produced triplanes in the months following the introduction of the Sopwith scout. Indeed, such was the Teutonic fear of the machine, that there existed a veritable race to produce a worthy counterpart to the English scout.

The most famous of these "dreideckers" is, of course, the Fokker design, but Anthony Fokker was far from the only German designer who attempted to reproduce Mr. Sopwith's success. To give one an idea as to the depth of the German fear of the Sopwith machine, I have enumerated here a small sampling of the attempts made by the Germans and Austrians to duplicate the technology.

The AEG triplane reached the prototype stage but was never entered into series production:

The Albatros Flugzeugwerke, noted for its rather brilliant biplane scouts, nonetheless attempted to produce triplanes to match the Sopwith. Both designs failed.

The Aviatik corporation, which achieved only moderate success with its D.I scout on the Italian front, nonetheless produced an experimental triplane of its own, in reaction to the Sopwith's appearance.

Hansa-Brandenberg, an Austrian aircraft manufacturer noted for its successful C.I two-seaters, and relatively unsuccessful D.I single-seat scouts, attempted to create a triplane of their own, during the German dreidecker craze.

Even Deutsche Flugzeug-Werke, a company not known for its scouts, created a triplane for consideration by the German Jadgstaffelen.

Of course, as any student of aviation knows, only one German triplane met with any kind of success, and that was the Fokker Dr.1. The machine was used by some of the leading German aces such as Manfred Freiherr von Richthofen, and Werner Voss.

Curiously, both Richthofen and Voss perished flying the scout, and it was not well-loved by the Germans. Nor was it produced in any significant quantity. This might lead one to believe that the age of the triplane had passed, but it fell to one of our American cousins to prove the Hun wrong, and to illustrate the capacity of the type to continue to give good service.

Glenn Curtiss, inventor of the aileron, once the fastest man on Earth (owing to his remarkable V-8 motorcycle), refined Mr. Sopwith's triplane design, producing a new, two-seater machine which retained the trademark maneuverability and climb rate for which the type was noted. To that, Mr. Curtiss added his racing pedigree. He streamlined the design wherever possible, removing unnecessary struts and bracing cables. The result was the Curtiss 18T, known unofficially as the Wasp.

The Curtiss machine, owing to its remarkable four-hundred horsepower engine, is capable of speeds in excess of one-hundred and sixty miles to the hour. This speed is greater than any known German scout, and indeed, greater than any scout in the world. Despite being a two-seater, and carrying a full military load, the Curtiss Wasp nonetheless succeeded in achieving a world speed record. Furthermore, a refined version of the machine also suceeded in achieving a world altitude record, showing the phenomenal rate of climb for which triplanes have long been admired. The machine's wing-loading is lighter than the Fokker D.VII biplane, indicating that the Curtiss, despite the extra weight of an observer, might nonetheless be maneuverable enough to dogfight with enemy scouts.

For the moment, the Curtiss machine represents the pinnacle of triplane design. However, as the triplane is, and always has been, a curiously English contraption, it is the opinion of your humble correspondent, that it will not be long before an Englishman wrests that title away from Mr. Curtiss' fine aeroplane.

1 comment:

  1. A well done article on the subject. The Triplane craze spawned several curious examples. The French attempt at designing a triplane in late 1916 exhibited a very curious wing arraignment. During 1915, the Nieuport Triplane was designed by Gustave Delage for Société Anonyme des Établissements Nieuport. One example was sent to Great Britain for evaluation. The design was never adopted as a production aircraft because of the poor handling characteristics due to the aircraft's unusual wing configuration.

    Another equally bizarre doomed design was the Ungarische Lloyd Flugzeug und Motorenfabrik 40.15 triplane fighter prototype. The 40.15 was a rather ungainly aircraft with many unique features. It had fully cantilevered wings, probably of mixed veneer and fabric construction.

    Best wishes;