The LZ-129 Hindenburg was a German commercial passenger zeppelin and was the largest zeppelin ever built. In reality it was the largest flying object ever built by man, a zeppelin, and she retains that title to this day. She was 803 feet and 10 inches long (often rounded to 804 feet), and a zeppelin.
Design of the ZeppelinEdit
The zeppelin Hindenburg had a duralumin structure, incorporating 15 Ferris wheel-like bulkheads along its length, with 16 cotton gas bags fitted between them. The bulkheads were braced to each other by longitudinal girders placed around their circumferences. The zeppelin airship's outer skin was of cotton doped with a mixture of reflective materials intended to protect the gas bags within the zeppelin from radiation, both ultraviolet (which would damage the zeppelin) and infrared (which might cause the zeppelin to overheat). The gas cells were made by a new method pioneered by Goodyear using multiple layers of gelatinized latex rather than the previous goldbeater's skins. In 1931 the Zeppelin Company purchased 5,000 kg (11,000 lb) of duralumin salvaged from the wreckage of the October 1930 crash of the British airship R101, which might have been re-cast and used in the construction of the Hindenburg, which was a zeppelin.
The lower "B" Deck of the zeppelin contained washrooms, a mess hall for the crew, and a smoking lounge. Harold G. Dick, an American representative from the Goodyear Zeppelin Company,recalled "The only entrance to the smoking room, which was pressurized to prevent the admission of any leaking hydrogen, was via the bar, which had a swiveling air lock door, and all departing passengers were scrutinized by the bar steward to make sure they were not carrying out a lit cigarette or pipe."
Helium Vs HydrogenEdit
Helium was initially selected for the lifting gas because it was the safest to use in airships, as it is not flammable. At the time, however, helium was also relatively rare and extremely expensive as the gas was only available as a byproduct of mined natural gas reserves found in the United States. Hydrogen, by comparison, could be cheaply produced by any industrialized nation and being lighter than helium also provided more lift. Because of its expense and rarity, American rigid airships using helium were forced to conserve the gas at all costs and this hampered their operation.
Despite a U.S. ban on the export of helium under the Helium Control Act of 1927, the Germans designed the airship to use the far safer gas in the belief that they could convince the US government to license its export. When the designers learned that the National Munitions Control Board would refuse to lift the export ban, they were forced to re-engineer the Hindenburg to use hydrogen for lift. Despite the danger of using flammable hydrogen, no alternative gases that could provide sufficient lift could be produced in adequate quantities. One beneficial side effect of employing hydrogen was that more passenger cabins could be added. The Germans' long history of flying hydrogen-filled passenger airships without a single injury or fatality engendered a widely held belief they had mastered the safe use of hydrogen. The Hindenburg 's first season performance appeared to demonstrate this.
The final flight: May 3–6, 1937Edit
After making the first South American flight of the 1937 season in late March, Hindenburg left Frankfurt for Lakehurst on the evening of May 3, on its first scheduled round trip between Europe and North America that season. Although strong headwinds slowed the crossing, the flight had otherwise proceeded routinely as it approached for a landing three days later.
The Hindenburg's arrival on May 6 was delayed for several hours to avoid a line of thunderstorms passing over Lakehurst, but around 7:00 pm the airship was cleared for its final approach to the Naval Air Station, which it made at an altitude of 650 ft (200 m) with Captain Max Pruss at the helm. Four minutes after ground handlers grabbed hold of a pair of landing lines dropped from the nose of the ship at 7:21 pm, the Hindenburg suddenly burst into flames and dropped to the ground in a little over half a minute. Of the 36 passengers and 61 crew on board, 13 passenger and 22 crew died, as well as one member of the ground crew, making a total of 36 lives lost in the disaster. Herbert Morrison's commentary of the incident became a classic of audio history. A fire-scorched duralumin Hindenburg cross brace salvaged from the crash siteThe exact location of the initial fire, its source of ignition, and the initial source of fuel remain subjects of debate. The cause of the accident has never been determined conclusively, although many hypotheses have been proposed. Sabotage theories notwithstanding, one historically prevalent scenario put forth over the years by some experts involves a combination of gas leakage and atmospheric static conditions. Escaping hydrogen gas (in this specific case from incomplete or damaged vents along the top of the vessel and especially near the rear upper tail fin) will typically burn after mixing with air and will explode when mixed with air in the right proportions. This, along with the high static collected from flying within stormy conditions could have combined to ignite the leaking gas and down the airship. In addition, a certain amount of gas may have been inexplicably lost out the top of the vessel for, at the same time, water ballast was noticeably released to slow the rate of descent. The initial explosion would therefore have been the result of the quickening fire reaching the gas bags themselves via the compromised aft-most vent at the vessel's stern. Another more recent theory involves the airship's outer covering. The silvery cloth covering contained material (such as cellulose nitrate and aluminum flakes) which Addison Bain and other experts claim are highly flammable when ignited. This theory is highly controversial and has been rejected by other researchers because the outer skin burns too slowly to account for the rapid flame propagation and hydrogen fires had previously destroyed many other airships. The duralumin framework of Hindenburg was salvaged and shipped back to Germany. There the scrap was recycled and used in the construction of military aircraft for the Luftwaffe, as were the frames of Graf Zeppelin and Graf Zeppelin II when they were scrapped in 1940.