Saturday, February 19, 2011

The First Zeppelins of Count Ferdinand von Zeppelin

The construction of Count Ferdinand von Zeppelin’s first airship, LZ-1, began in June, 1898 in a floating wooden hangar on the Bodensee (Lake Constance) at Manzell (Friedrichshafen) in Southern Germany, not far from the Swiss border. The movable, floating shed allowed the ship to be positioned into the wind to enter or leave its hangar.

LZ-1 in its floating shed on the Bodensee.

The ship was completed in the winter of 1899, but Count von Zeppelin decided to wait until the summer of 1900 before attempting to fly his invention. The ship was inflated with hydrogen gas in June, and made its maiden flight on July 2, 1900. The first flight lasted about 18 minutes and covered about 3-1/2 miles over the lake.

LZ-1 (Luftschiff Zeppelin 1) was 420 feet long, 38-1/2 feet in diameter, and contained approximately 399,000 cubic feet of hydrogen in 17 gas cells made of rubberized cotton fabric. Two metal gondolas were suspended below the ship (one forward and one aft) and each gondola housed a 4-cylinder water-cooled Daimler gasoline engine producing about 14 horsepower. Each engine was connected by long shafts to two outrigger propellers mounted on either side of the hull. Pitch was controlled by a sliding weight suspended under the hull which could be shifted fore and aft; there were no elevators for pitch control, or fins for stability.

Luftschiff Zeppelin 1.

The first flight of LZ-1 was the culmination of years of planning by Count Zeppelin, but as a first attempt the ship had understandable weaknesses: LZ-1 was overweight, and a severe lack of engine power and speed made it difficult to control in even slight winds; the engines themselves were unreliable, and one failed during the short maiden flight; the ship suffered from poor controllability due to its lack of horizontal or vertical stabilizing fins and control surfaces, and the sliding weight system jammed, eliminating pitch control; and most importantly, the structure itself lacked rigidity due to its weak tubular frame, which hogged during flight, with its center portion rising high above its drooping bow and stern.

Attempts were made to increase the rigidity of the framework and address the other problems, and two additional flights were made, but the flights did not impress the military representatives in attendance that Zeppelin’s project deserved public funds, and Count Zeppelin was out of money. Zeppelin was forced to dismantle LZ-1.

But while LZ-1 itself was not a success, Count von Zeppelin’s basic concept — of a long rigid metal frame containing individual gas cells and covered by fabric — was sound, and formed the basis for all future zeppelin airships.

Count Zeppelin’s second ship, LZ-2, was not built until five years later, with funds raised partly from a lottery approved as a favor by the King of Württemberg, and partly by the mortgage of Countess Zeppelin’s family estates.

LZ-2 made its only flight on January 17, 1906. Zeppelin had replaced the 14 hp engines used on LZ-1 with 80 hp Daimler engines, which gave LZ-2 sufficient speed to maneuver in light winds, but engine failure forced an emergency landing during the ship’s very first flight, and it was destroyed on the ground by a storm that evening.

Destruction of LZ-2.

While an improvement over LZ-1, Count Zeppelin’s second ship still did not incorporate basic design elements which would later be recognized as essential to flight stability and control, such as vertical and horizontal stabilizers and control surfaces. But LZ-2 did represent a significant technical advance due largely to engineer Ludwig Dürr; the weak tubular girders of LZ-1 were replaced by triangular girders (visible in photo above), which provided dramatically improved rigidity and strength. Triangular girders similar to those used on LZ-2 would be used on every subsequent zeppelin airship, and Ludwig Dürr would remain as chief engineer, designing every ship built by the Zeppelin Company after LZ-2.

LZ-2. The stronger, more rigid frame provided by Ludwig Dürr's triangular girders can be seen, but the ship still lacked fins for stability or control.

The next two ships, LZ-3 and LZ-4, were even greater advances in technology, with huge increases in controllability, power, speed, range, and payload. Large horizontal fins and elevators finally provided greater pitch control and stability, and the ships were capable of producing aerodynamic lift. Longer and more reliable flights became possible; in 1907, LZ-3 made a flight of 8 hours, and on July 1, 1908, LZ-4 made a flight of 12 hours over Switzerland.

LZ-3 in flight.

The record-breaking Switzerland flight of LZ-4 brought national attention to the success of Count Zeppelin and his machine, and the public began to look on the airship as a practical innovation. On July 3, 1908, King Wilhelm II of Württemberg and his wife, Queen Charlotte, were passengers on the fifth flight of LZ-4.

Tail of LZ-3, showing horizontal stabilizers which were lacking on LZ-1 and LZ-2.

The German government promised financial support for Count Zeppelin’s efforts if his ship could make an endurance flight of 24 hours, and confidant in his ship’s ability, Zeppelin agreed to the challenge. LZ-4 departed the Bodensee on August 4, 1908, for a 24-hour trial.

LZ-4 leaving its hangar on the Bodensee for the 24 hour test flight that ended at Echterdingen.

Just as it seemed that Count Zeppelin and his team had mastered the basics of airship design and operation, LZ-4 was forced to make an emergency landing in a field at the town of Echterdingen on August 5, 1908, during the 24-hour endurance flight. Pulled by a sudden storm from its temporary mooring, the ship crashed and was soon destroyed by a fiery explosion of hydrogen.

Wreckage of LZ-4 at Echterdingen.

In response to the crash, rather than lose faith in Count Zeppelin’s work, the German public rallied behind Zeppelin’s efforts; in what became known as the “Miracle at Echterdingen,” Germans contributed 6 million marks for the construction of a new airship and gave new life to the zeppelin enterprise.

Wreckage of LZ-4 at Echterdingen.

The fervent financial and political support of the German public and government following the crash at Echterdingen allowed the Count to establish the Luftschiffbau Zeppelin (Zeppelin Construction Company) in September, 1908. Alfred Colsman was the Zeppelin Company’s business manager, and in 1909, journalist Hugo Eckener joined as the company’s director of public relations; within 2 years, Eckener would be an airship commander.

Early zeppelin under construction at floating hangar on the Bodensee.

Colsman would shortly establish DELAG, the Deutsche Luftschiffahrts-Aktiengesellschaft (German Airship Transportation Corporation Ltd) as a affiliate of the Zeppelin Company, to commercialize zeppelin travel by providing passenger service.

Early zeppelin at floating hangar on Bodensee.


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