The Zeppelin-Staaken plant (Plate 17), located in the outskirts of Berlin is considered the most modern airship factory in the world.

Into it were put all the knowledge and experience of ten years of practical airship production. There were at one time two large sheds 820 feet (250 meters) long, 150.8 feet (46 meters) wide and 114.8 feet (35 meters) high, with a ring building shed between them, great workshops, research laboratories, administration building, hydrogen plant and all accessories.

The latest and most efficient machinery and tools then devised were provided. A large airdrome was constructed, as it was planned to make Staaken the post-war center of Zeppelin airship activity.

Here it was planned to locate both stationary and rotary sheds, the latter turning like a locomotive turn-table, making it possible to point their entrances in any direction the prevailing wind might dictate, to insure safe launching or landing of the Zeppelins. Then there were to be airplane factories on the same airdrome. It was at the Staaken plant that the L-59 was fabricated for the record flight to German East Africa and return. In all, twelve Zeppelins were built there.

The Duralumin Works

During the war two plants were put up in the vicinity of Friedrichshafen for making duralumin materials such as angle bars, strips, all kinds of girders, and other parts of the Zeppelin skeleton. They were operated for the most part with female labor.

[PLATE 33: The "DELAG" Pa.s.senger Zeppelin "Hansa", 1912.

The "DELAG" Pa.s.senger Zeppelin "Sachsen", 1913.]

The Woodworking Factory

A woodworking factory (Holzindustrie G.M.B.H.-Meckenbeuren) also was established near Friedrichshafen for the manufacture of propellers, etc.

It has recently been enlarged and is operating at full capacity producing materials for buildings, dwellings, etc. During the war the specially designed Zeppelin propellers were made at Goppingen.

The Maybach Motor Works

One of the accessory companies founded by Zeppelin in 1909 was the Maybach Motor Factory (Maybach-Motorenbau) (Plate 18), at Friedrichshafen. It was enlarged considerably during the war, supplying practically all the airship motors used. Today the Maybach works include three large three story factory buildings, parts of which are devoted to executive offices, two workshops of recent origin occupying two acres, many engine testing stands, laboratory, and a power plant fully equipped with the latest machinery. The entire plant is under the management of Mr. Maybach, inventor of the only motor designed for airships alone. One reason for the peculiar efficiency of the plant is the special workman's training department which has received considerable attention from the executives.

[PLATE 34: "DELAG"-Zeppelin Harbor at Frankfort a.M., 1912.

"DELAG"-Zeppelin Harbor at Baden-Baden, 1910.]

The first Maybach motors were produced in 1912 (Plate 19), and were 140 and 180 horsepower. They contributed largely to the success of the commercial Zeppelin before the war. In 1915 a 240 horsepower motor was built, and this was the princ.i.p.al motor used on the military and naval Zeppelins. Maybach produced an entirely new motor in 1917. It supplied from 260 to 320 horsepower and is noted as the first supercompression motor. Quickly recognized as the best engine for airplanes, it became the leading German aviation motor until late in 1918 when other motors built on similar principles appeared and were found more adaptable to the planes. Maybach, meanwhile, developed other types (Plate 20), princ.i.p.ally 160 and 260 horsepower units for heavier-than-air craft.

The following table ill.u.s.trates the development in types and performance of engines:

Performance of Engines-1892-1918

================================================================ | | | |Weight| Unit | Fuel | | | |Revolutions| Kg. | Weight |Consumption | Year | Motor | H. P.|per minute | |Kg./H. P.| Gr./hp-hr | ----------------------------------------------------------------| 1892 | Daimler | 11 | 440 | 500 | 45,5 | 500 | 1899 | Daimler | 15 | 680 | 385 | 25,7 | 400 | 1905 | Daimler | 90 | 1050 | 360 | 4,00 | ... | 1907 | Daimler | 100 | 1080 | 400 | 4,00 | 265-240 | 1909 | Daimler | 115 | 1100 | 420 | 3,65 | ... | 1910 | Daimler | 120 | 1100 | 450 | 3,75 | 225 | 1910 | Maybach | 145 | 1100 | 450 | 3,1 | 240 | 1913 | Maybach | 180 | 1200 | 462 | 2,56 | 225 | 1914 | Maybach | 210 | 1250 | 414 | 1,97 | 225 | 1915 | Maybach | 240 | 1400 | 365 | 1,52 | 200 | 1917 | Maybach | 260 | 1400 | 400 | 1,54 | 200 | 1918 | Maybach | 260 | 1400 | 390 | 1,50 | 200 | ----------------------------------------------------------------

The Employment and Training System

Apprentices and girls are given a thorough examination and test to determine their fitness for the work, which requires the utmost accuracy. Then they enter a twelve weeks probationary service. Their apprenticeship lasts four years. All apprentices are given instruction by engineers and foremen in physics, chemistry, knowledge of materials, model making, foundry work, algebraic calculation methods, the handling of graphics, curves, statistics, price calculation, machines and tools and particularly the principles and functions of internal combustion engines.

On January 1st, 1918, 1980 workmen were employed, 416 of them women.

There were 57 women on the executive and office staff of 217. On November 1st, that year, 3300 workmen and 349 others were employed, 599 of them women.

[PLATE 35: "DELAG"-Zeppelin Harbor at Hamburg, 1912.

"DELAG"-Zeppelin Harbor at Leipzig, 1913.

"Sachsen" landing for first time after completion of harbor June 1913.]

The Zeppelin-Maybach Gearless Car

In the fall of 1921 Maybach exhibited for the first time the 22-70 horsepower gearless motor car, designed to simplify operation. Only what is termed the direct speed is used in driving; except for grades of more than 10%, and for the starting on these grades, when apart from the rest of the mechanism a single gear is used by pushing down a pedal. When it is released, the direct grip is automatically restored without noise or vibration. Backing is accomplished with the electric starting motor by means of a pedal. Smaller cars of this type are now under construction.

New Methods of Gas Bag Fabrication

The early gas bags for the Zeppelins were made of rubberized cotton fabric. This material was comparatively heavy and further, it allowed the hydrogen gas to deteriorate during prolonged operations. Count Zeppelin experimented with various materials, particularly goldbeater skins, which are the big intestines of oxen and other cattle, treated until they become like leather and then they are very thin, tough and so durable that they wear much longer than fabric. Zeppelin learned that goldbeater's skins held gas better, also, and unlike rubberized fabric, practically eliminated the danger of electrical sparks due to friction or tearing.

He organized the Gasbag Manufacturing Company (Ballon-Hullen G.M.B.H.) at Tempelhof in 1912, to carry out this development and goldbeater's skins were used exclusively, as the loss of two Zeppelins that year was traced directly to the balloon fabric in the gas bags causing sparks which exploded the hydrogen. The ships were the LZ-12 and the Schwaben, the former exploding during inflation and the latter while moored at Dusseldorf.

[PLATE 36: "DELAG"-Zeppelin Harbors at Liegnitz and Dresden, 1913-14.

"DELAG"-Zeppelin Harbor and Manufacturing Plant at Potsdam (near Berlin), 1915.]

The goldbeater skins possessed certain disadvantages, however. For one thing, they were difficult to handle because of their small size; so they were shingled on to thin cotton fabric. Since 1917 silk has been used, the combination when prepared being so light and thin as to be transparent. In fact, the Zeppelins hulls are themselves nearly transparent, the fabric envelope and gas bags being so thin that one can make out figures silhouetted on the opposite side of the hull when it faces the light.

The Tempelhof factory, with Mr. Trenkmann as Manager, now includes many buildings and workshops, several put up recently for dyeing and treating fabrics. During the war a thousand persons were employed. The gas bags used in all the German airships were made there; and the factory working with another firm under a patent license agreement, made a majority of the German observation balloons.

The Maag-Zeppelin Gear Works

It was not long after the war started that Count Zeppelin had difficulty in securing delivery of cog-wheels, etc. In 1915 he co-operated with Mr.

Maag, a Swiss engineer, in starting the Friedrichshafen Cog-wheel and Gear Factory (Zahnradfabrik Friedrichshafen G.M.B.H.), another subsidiary (Plate 18.). The plant is as modern as they could make it.

The buildings occupy three acres. They include office buildings, workshops for hobbing, heat-treating, grinding and polishing cog-wheels and the complete gear transmissions. Aluminum castings are obtained from the foundry of the parent company, Luftschiffbau-Zeppelin.

The gear works is equipped throughout with automatic machines built on the Maag patents. His cog-wheel involves a new principle, giving utmost safety and freedom from wear and noise. Specially designed testing machines are used, guaranteeing precision of the gear wheels.

[PLATE 37: "DELAG" Zeppelin Route Chart, 1912-13.]

During the war the company made all the gearing on the Zeppelins and airplanes. The factory is now operating at full capacity, employing 500 men, making motor car gears, transmissions, etc. The manager is Dipl.

Ing. Count von Soden.

The Hangar Construction Company

Back in 1913 a subsidiary was founded, first as a consulting engineering concern; but soon thereafter it became the Zeppelin Hangar Construction Company (Zeppelin Hallenbau G.M.B.H.). Through long practical experience it is prepared to build and equip complete airship harbors and dock yards, prepare landing fields and airdromes. One of the princ.i.p.al developments with which it has been accredited is the rotary shed, single or double. It has erected special workshops, gas plants and all the accessories of a modern flying terminal.

The company designed and constructed the two modern sheds at Friedrichshafen, the entire Staaken plant, the "DELAG" airship harbors and nearly all the other airports in Germany. Many hangars and workshops in Germany today were put up by the company using specially patented construction methods. In all some twenty-four complete airship harbors have been built from start to finish by this organization, which is under the management of Mr. Milatz and his staff of experts varying between 20 and a hundred members.

Zeppelin Production of Airplanes

In 1916, the airship building personnel conducted experiments with airplanes made of airship duralumin girders covered with fabric. The object was to secure a plane which would meet the technical requirements of aerial photography. Though their activities were devoted to the airship building programme, the engineers managed to produce an experimental machine of that type. On its first trials, it proved so superior to existing types that the army urgently requested early delivery of a number of machines. There was little time to do the work, however, and at the end of the war only twenty had been completed. They were destroyed, afterward, under the terms of the Versailles treaty.