The Martin bomber.This plane is equipped with two Liberty engines and has many long-distance records. It flew from Pittsburgh to Washington, a distance of 175 miles, in 1 hour and 15 minutes. It also flew from the Atlantic to the Pacific.
The Martin bomber.This plane is equipped with two Liberty engines and has many long-distance records. It flew from Pittsburgh to Washington, a distance of 175 miles, in 1 hour and 15 minutes. It also flew from the Atlantic to the Pacific.
The Martin bomber.
This plane is equipped with two Liberty engines and has many long-distance records. It flew from Pittsburgh to Washington, a distance of 175 miles, in 1 hour and 15 minutes. It also flew from the Atlantic to the Pacific.
The Gibson Company of Muskegon made the springs.
The Packard Company made the patterns and several dies in order to obtain drop-forgings of the proper quality. It also machined the crank-shafts.
After the preliminary tests passed by the 8-cylinder engine, August 25, 1917, Government Inspector Lynn Reynolds said “that the design has passed from the experimental stage into the field of proven engines.” The machine was tested at Pike’s Peak, Colorado, for altitude in August, 1917. Reports from the battle-field decided the board to build 12-cylinder engines. Thereupon standardized parts made interchangeable for all types of Liberty engines were detailed, and orders placed with the various firms named to build the same. Production was started on a large scale.
On October 17 the production of the Liberty motor started, over six months after we entered the war.
The delivery of the first Liberty 12 was made on Thanksgiving Day, 1917.
One of the unrecorded incidents of this period concerned the “scrapping” of $400,000 worth of semi-finished parts of an automotive aircraft engine, which was assumed O. K., and parts had been ordered for 250 motors. It was actually in production at the time Hall and Vincent were ignoring practically all its features and “laying out” the designs for the Liberty 8 and Liberty 12. It had never been tested in a plane, and its design and all its parts were rejected.
Owing to the slowness of production due to the newgigs, dies, tools, etc., necessary to build the engines, much criticism was directed at the lack of shipments of Liberty engines for army air service in the winter months of 1917.
Charged with the necessity of protecting the American army transport, the Navy Department had first call on all air-service equipment. As a result it received the first Liberty 12’s turned out. These were installed in navy aeroplanes, where they did good work.
The preliminary Liberty 8 was delivered to the Bureau of Standards, Washington, D. C., July 3, 1917, by the group of industrial concerns named. A 54-hour test was made of a Liberty 12 on August 25 by the Bureau of Standards. The Liberty 12 was detailed for quantity production, and the actual work was begun, and the work done by these companies in producing Liberty-engine parts is above praise. It was then that the mighty energies of their splendid organizations demonstrated the ability of American industrial life to fight the battle behind the lines.
War Department Statement
Departing from its policy of secretiveness concerning all things of a military character, the United States War Department on May 15, 1918, issued an authorized statement dealing with the technical features and characteristics of the Liberty 12, then in quantity production. This statement was published in theCongressional Recordof an early subsequent date.
Secretary of War Baker in his report published elsewhere in this book gives the following account of Liberty motors built:
Production of Service Engines
In view of the rapid progress in military aeronautics, the necessity for the development of a high-powered motor adaptable to American methods of quantity production was early recognized. The result of the efforts to meet this need was the Liberty motor—America’s chief contribution to aviation, and one of the great achievements of the war. After this motor emerged from the experimental stage, production increased with great rapidity, the October output reaching 4,200, or nearly one-third of the total production up to the signing of the armistice. The factories engaged in the manufacture of this motor, and their total production to November 8, are listed in Table 21.Table 21.—Production or Liberty Motor to November 8, 1918, By Factories:Packard Motor Car Co4,654Lincoln Motor Co3,720Ford Motor Co3,025General Motors1,554Nordyke & Marmon Co433———Total13,396Of this total, 9,834 were high-compression, or army type, and 3,572 low-compression, or navy type, the latter being used in seaplanes and large night bombers.In addition to those installed in planes, about 3,500 Liberty engines were shipped overseas, to be used as spares and for delivery to the Allies.Other types of service engines, including the Hispano-Suiza 300 horse-power, the Bugatti, and the Liberty 8-cylinder, were under development when hostilities ceased. The Hispano-Suiza180 horse-power had already reached quantity production. Nearly 500 engines of this type were produced, about half of which were shipped to France and England for use in foreign-built pursuit planes.Table 22 gives a résumé of the production of service engines by quarterly periods:Table 22.—Production or Service Engines in 1918:Name of engineJan. 1 toMar. 31Apr. 1 to,June 30July 1 toSept.30Oct. 1 toNov. 8TotalLiberty 12, Army1221,4934,1164,0939,824Liberty 12, Navy1426331,7101,0873,572Hispano-Suiza 180 h.p.......185284469Later the Statistical Department of the War Department issued the following. The number of planes and engines shipped by the Bureau of Aircraft Production to depots and storehouses from the date of the armistice to February 14:Liberty 12 service engines4,806OX-5 elementary training-engines1,261Le Rhone advanced training-engines994De Havilland-4 observation planes524Hispano 180 advanced training-engines343Hispano 150 advanced training-engines254JN6-H advanced training-planes174JN4-D elementary training-planes131The Packard Motor Car Company made the final deliveries of Liberty 12 motors during the week ended March 21, 1919. This completes all contracts. The following shows the number and per cent produced by each factory:FirmNumberproducedP.C.of totalPackard Motor Car Co.6,50032Lincoln Motor Co.6,50032Ford Motor Co.3,95019General Motors Co.2,52812Nordyke & Marmon Co.1,0005———Total20,478
In view of the rapid progress in military aeronautics, the necessity for the development of a high-powered motor adaptable to American methods of quantity production was early recognized. The result of the efforts to meet this need was the Liberty motor—America’s chief contribution to aviation, and one of the great achievements of the war. After this motor emerged from the experimental stage, production increased with great rapidity, the October output reaching 4,200, or nearly one-third of the total production up to the signing of the armistice. The factories engaged in the manufacture of this motor, and their total production to November 8, are listed in Table 21.
Table 21.—Production or Liberty Motor to November 8, 1918, By Factories:
Of this total, 9,834 were high-compression, or army type, and 3,572 low-compression, or navy type, the latter being used in seaplanes and large night bombers.
In addition to those installed in planes, about 3,500 Liberty engines were shipped overseas, to be used as spares and for delivery to the Allies.
Other types of service engines, including the Hispano-Suiza 300 horse-power, the Bugatti, and the Liberty 8-cylinder, were under development when hostilities ceased. The Hispano-Suiza180 horse-power had already reached quantity production. Nearly 500 engines of this type were produced, about half of which were shipped to France and England for use in foreign-built pursuit planes.
Table 22 gives a résumé of the production of service engines by quarterly periods:
Table 22.—Production or Service Engines in 1918:
Later the Statistical Department of the War Department issued the following. The number of planes and engines shipped by the Bureau of Aircraft Production to depots and storehouses from the date of the armistice to February 14:
The Packard Motor Car Company made the final deliveries of Liberty 12 motors during the week ended March 21, 1919. This completes all contracts. The following shows the number and per cent produced by each factory:
The Hispano-Suiza
It is evident from the records made by the German Mercedes, which are given in another chapter, that it was the best aviation motor in existence in July, 1914. Naturally, this motor had considerable influence on the aeronautical engineers of the Allies. Mr. Marc Birkright, a Swiss engineer to the Hispano-Suiza Company, automobile builders in Barcelona, Spain, and Paris, designed the aviation motor which now holds the world’s record for altitude—28,900 feet. When he designed the motor he had in mind the construction of the machine-tools necessary to build the same.
In the summer of 1915 the first motor of 150 horse-power was delivered to France after a test of 15 consecutive hours. The next two were tested for 50 hours, and proved satisfactory. France placed a large order, and the Hispano-Suiza factory began production at the end of 1915. Before the end of the war three Italian, fourteen French, one British, one Japanese, and one Spanish factory, besides 25,000 people in America, were producing Hispano-Suiza engines.
The motor had great success in the single-seater fighters flown by such men as Captain Georges Guynemer, Lieutenant Fonck, Nungesser, and dozens of other aces.
With the exception of increasing the horse-power from 150 to 180, 200, 300, very few changes were made in this motor in this country.
Four hundred and fifty engines were ordered by theFrench Government of the General Aeronautic Company of America early in 1916. When the Wright-Martin Aircraft Company was formed in September of that year, less than 100 motors had been delivered. At the end of July, 1917, 1,000 motors were on their books.
From July, 1917, the American factory concentrated on the 150 horse-power engine. The Wright-Martin Company had to build its own plant for aluminum castings for the engine. In November of that year the company was ordered to build 200 horse-power engines, and later the 300 horse-power was ordered. In May, 1918, the French and British Governments decided to use the 300 horse-power motor in large quantities, and by October the factories of the company in New Brunswick and Long Island City were tooled up to produce 1,000 motors a month, which represented a $50,000,000 order. Early in the spring of 1918, 15 motors a day were produced, and in August of that year the company was committed to a schedule of 30 engines a day.
The Rolls-Royce Motor
“There is no doubt,” saysLondon Motor, “that the conception of the Rolls-Royce aeronautic engine is extremely good, but no one will gainsay the fact that the care exercised in manufacture and the elaborate operations through which the various parts have to pass are in part the reason for its success. This refinement necessitates the passing of certain parts through fifty or sixty operations that might be easily carriedout in a comparatively small number if superfine finish were not desired or required.
“The Rolls-Royce ‘Eagle’ engine, originally designed as a 200 horse-power unit, developed 255 horse-power on the first brake test. Diligent research and experiment were pursued with extraordinary results, as will be seen in the following record of official brake tests, all made without any enlargement of the dimensions or radical alteration in design. A 12-cylinder engine, 4½-inch bore by 6½-inch stroke, developed in March, 1916, 266 horse-power at 1,800 R. P. M. By July the power was increased to 284 horse-power; nine months from this date, in September, 1917, it had risen to 350 horse-power, and in February, 1918, 10 more horse-power was added, making the total 360 horse-power. In addition to the ‘Eagle,’ a smaller engine giving 105 horse-power at 1,500 R. P. M. was turned out under the name of the ‘Hawk.’
“The ‘Eagle’ engine was used in the large Handley Page machine, and in the successful long-distance bombing raids into Germany. In 1916 another engine for fighting planes was added to the list, under the name of ‘Falcon,’ and was almost exclusively used in the Bristol fighting plane. The increase in the power developed by the ‘Falcon’ engine, which has a 4-inch bore, was as follows: April, 1916, 206 horse-power at 1,800 R. P. M.; July, 1918, 285 horse-power at 2,000 R. P. M.
“From the stamping-plant through the machine, gear-cutting, and grinding shops and welding department,the care with which each engine is turned out is apparent. Take apart a cylinder which has a stamped sheet-metal water-jacket welded externally, and the original billet is found out of which the cylinder was made, but reduced almost by half when it is ready to receive the valve cages, and during the process of removal of the metal and forming into proper shape the piece is subjected to several heat treatments so as to bring the metal to that stage of perfection needed for the work it has to perform. The elbow cages that are fitted to the cylinders might be cast and cored, but the valve cage is an actual solid stamping, and the right-angle bend through the elbow has to be bored out by special machines.
“One point illustrates the care in the choice of metal and the multifarious operations through which each part has to pass. A crank-shaft stamping with extension piece on the rear and about one foot long is cut off, and test pieces of this metal, properly numbered with each crank-shaft, are passed through the same treatment as the crank-shaft itself, and then subjected to minute examination by highly skilled engineers. The actual manufacturing side of the work would naturally be very similar to the manufacture of a car engine, but one obtains a better perspective of what an engine is subjected to by passing from the erecting and manufacturing shops to the engine-testing shop, where the ear-splitting reports from the open exhausts of a number of engines being tested at the same time are heard. Here one sees how dissimilarthe aviation engine is from the car engine. It is almost impossible, without having actually witnessed it, to picture to oneself a 12-cylinder engine running at 2,200 R. P. M. against a brake test. As the exhaust ports are on either side of the engine, the cylinders being placed in the form of a V, it is possible, by passing on either side, to look into the combustion-chamber and see the valves rising and the spit of the exhaust, and, what is almost incredible, that the exhaust valves are actually red-hot and run in this condition for hours. Little wonder is it that the valves have to be made of superfine material and of particular form.
“The variation in the color of the flame of the exhaust, due to strong and weak mixtures, makes it quite possible to test the good running of an engine by the color of its exhaust. The strength of the mixture has necessarily to be altered according to atmospheric conditions and the altitude to which the pilot desires to climb.
“No doubt airplane-engine practice of the last four years and the advance that it has made will be reflected in a very marked degree in the automobile, not necessarily by fitting large airplane engines in cars, but by applying to car practice the knowledge that has been gained in manufacture.
“The Rolls-Royce works had in 1907 an area of 5,312 square yards, and during the war this was increased to 67,935 square yards. At the present time the payroll is somewhere in the neighborhood of 8,650.”