The Hindenburg Disaster
The Hindenburg disaster at Lakehurst, New Jersey on May 6, 1937 brought an abrupt end to the age of the rigid airship.
After more than 30 years of passenger travel on German commercial zeppelins – during which tens of thousands of passengers flew over a million miles on more than 2,000 flights without a single injury – the era of the passenger zeppelin came to an end in a few fiery minutes.
It seems clear that the disaster was caused by an electrostatic discharge (in simple terms, a spark) that ignited hydrogen that had leaked from a gas cell.
The exact cause of the discharge is open to discussion; the source of ignition could have been a coronal discharge (“St. Elmo’s Fire), but was most likely caused by a difference in electrical potential between the airship and the surrounding air. The airship was 60 meters (approximately 200 feet) above the airfield in an electrically charged atmosphere, but was grounded by its landing lines; the difference in charge between the airship and the surrounding air likely caused electrical discharges.
The cause of the hydrogen leak is more of a mystery, but we know the ship experienced a significant leakage of hydrogen before the disaster.
One thing is clear; the disaster was caused by the ship’s hydrogen had nothing to do with the zeppelin’s fabric covering. In fact, Hindenburg was just one of a long line of hydrogen airships destroyed by fire as a result of their highly flammable lifting gas.
Hindenburg began its last flight on May 3, 1937 [see complete Hindenburg Flight Schedule], carrying 36 passengers [see Hindenburg Passenger List] and 61 officers, crew members, and trainees [see Hindenburg Crew List].
The ship left the Frankfurt airfield at 7:16 PM and flew over Cologne, and then crossed the Netherlands before following the English Channel past the chalky cliffs of Beachy Head in southern England, and then heading out over the Atlantic shortly after 2:00 AM the next day.
Hindenburg followed a northern track across the ocean [view chart], passing the southern tip of Greenland and crossing the North American coast at Newfoundland. Headwinds delayed the airship’s passage across the Atlantic, and the Lakehurst arrival, which had been scheduled for 6:00 AM on May 6th, was postponed to 6:00 PM.
By noon on May 6th the ship had reached Boston, and by 3:00 PM Hindenburg was over the skyscrapers of Manhattan in New York City (view photograph).
The ship flew south from New York and arrived at the Naval Air Station at Lakehurst, New Jersey at around 4:15 PM, but the poor weather conditions at the field concerned the Hindenburg’s commander, Captain Max Pruss, and also Lakehurst’s commanding officer, Charles Rosendahl, who sent a message to the ship recommending a delay in landing until conditions improved. Captain Pruss departed the Lakehurst area and took his ship over the beaches and coast of New Jersey to wait out the storm. By 6:00 PM conditions had improved; at 6:12 Rosendahl sent Pruss a message relaying temperature, pressure, visibility, and winds which Rosendahl considered “suitable for landing.” At 6:22 Rosendahl radioed Pruss “Recommend landing now,” and at 7:08 Rosendahl sent a message to the ship strongly recommending the “earliest possible landing.”
Hindenburg approached the field at Lakehurst from the southwest shortly after 7:00 PM at an altitude of approximately 600 feet. Since the wind was from the east, after passing over the field to observe conditions on the ground, Captain Pruss initiated a wide left turn to fly a descending oval pattern around the north and west of the field, to line up for a landing into the wind to the east.
While Captain Pruss (who was directing the ship’s heading and engine power settings) brought Hindenburg around the field, First Officer Albert Sammt (who was responsible for the ship’s trim and altitude, assisted by Watch Officer Walter Ziegler at the gas board and Second Officer Heinrich Bauer at the ballast board), valved 15 seconds of hydrogen along the length of the ship to reduce Hindenburg’s buoyancy in preparation for landing.
As Pruss continued the slow left turn of the oval landing pattern, reducing, and then reversing, the power from the engines, Sammt noticed that the ship was heavy in the tail and valved hydrogen from cells 11-16 (in the bow) for a total of 30 seconds, to reduce the buoyancy of the bow and keep the ship in level trim. When this failed to level the ship, Sammt ordered three drops of water ballast, totaling 1,100 kg (2,420lbs), from Ring 77 in the tail, and then valved an additional 5 seconds of hydrogen from the forward gas cells. When even these measures could not keep the ship in level trim, six crewmen were ordered to go forward to add their weight to the bow.
(That Captain Pruss personally directed the ship’s heading and power settings during the landing evolution was an exception to the usual German operating procedure. Typically, during the landing of Hindenburg or Graf Zeppelin, the rudder and power were under the direction of one senior watch officer, while the elevators, ballast, and gas were under the direction of another senior watch officer; the ship’s captain observed all operations, but only intervened in the case of difficulty or disagreement with the actions of his officers. The German procedure was noted frequently by American naval observers, perhaps because it differed so greatly from the practice followed by the United States Navy. During Hindenburg’s final landing maneuver, however, Captain Pruss personally directed the rudder and power, while Albert Sammt directed the elevators, ballast, and gas. Perhaps Pruss was simply used to this arrangement from his time as a watch officer, or perhaps a re-ordering of roles occurred because of the presence of senior captain and DZR flight director Ernst Lehmann on the bridge, but as far as this author knows, Captain Pruss never commented on the matter publicly, nor did Pruss ever try to evade his responsibility as commander by suggesting that Captain Lehmann was in actual operational control at the time of the accident.)
While Sammt was working to keep the ship in trim, the wind shifted direction from the east to the southwest. Captain Pruss now needed to land into the wind on a southwestly heading, rather than the easterly heading he had originally intended when he planned his oval landing pattern. Hindenburg was now close to the landing area, however, and did not have a lot of room to maneuver before reaching the mooring mast. Anxious to land quickly, before weather conditions could deteriorate, Captain Pruss decided to execute a tight S-turn to change the direction of the ship’s landing; Pruss ordered a turn to port to swing out, and then a sharp tight turn to starboard to line up for landing into the wind. (Some experts would later theorize that this sharp turn overstressed the ship, causing a bracing wire to snap and slash a gas cell, allowing hydrogen to mix with air to form a highly explosive combination.)
After the S-turn to change the direction of landing, Pruss continued his approach to the mooring mast, adjusting power from the two forward and two rear engines, and at 7:21, with the ship about 180 feet above the ground, the forward landing ropes were dropped.
A few minutes after the landing lines were dropped, R.H. Ward, in charge of the port bow landing party, noticed what he described as a wave-like fluttering of the outer cover on the port side, between frames 62 and 77, which contained gas cell number 5 . He testified at the Commerce Department inquiry that it appeared to him as if gas were pushing against the cover, having escaped from a gas cell. Ground crew member R.W. Antrim, who was at the top of the mooring mast, also testified that he saw that the covering behind the rear port engine fluttering.
At 7:25 PM, the first visible external flames appeared. Reports vary, but most witnesses saw the first flames either at the top of the hull just forward of the vertical fin (near the ventilation shaft between cells 4 and 5) or between the rear port engine and the port fin (in the area of gas cells 4 and 5, where Ward and Antrim had seen the fluttering).
For example, Lakehurst commander Rosendahl described a “mushroom shaped flower” of flame bursting into bloom in front of the upper fin. Navy Lt. Benjamin May, the assistant mooring officer, who was atop the mooring mast, testified that an area just behind the rear port engine (where Ward and Antrim reported the fluttering) “seemed to collapse,” after which he saw streaks of flame followed by a muffled explosion, and then the entire tail was engulfed by flame. Navy ground crew member William Bishop described seeing flames “inside” the ship a little above and aft of the rear port engine car.
Several witnesses inside the ship also saw the beginning of the fire. Helmsman Helmut Lau, who was stationed at the auxiliary control stand in the lower fin, heard “a muffled detonation and looked up and saw from the starboard side down inside the gas cell a bright reflection on the front bulkhead of cell No. 4.”
Lau described the flames he saw at cell 4 at the inquiry: “The bright reflection in the cell was inside. I saw it through the cell. It was at first red and yellow and there was smoke in it. The cell did not burst on the lower side. The cell suddenly disappeared by the heat…. The fire proceeded further down and then it got air. The flame became very bright and the fire rose up to the side, more to the starboard side, as I remember seeing it, and I saw that with the flame aluminum parts and fabric parts were thrown up. In that same moment the forward cell and the back cell of cell 4 also caught fire [cell 3 and cell 5]. At that time parts of girders, molten aluminum and fabric parts started to tumble down from the top. The whole thing only lasted a fraction of a second.”
The fire quickly spread and soon engulfed the tail of the ship, but the ship remained level for a few more seconds before the tail began to sink and the nose pointed upward to the sky, with a blowtorch of flame erupting from the bow where twelve crew members were stationed, including the six who were sent forward to keep ship in trim.
In the port and starboard promenades on the passenger decks, where many of the passengers and some of the crew had gathered to watch the landing, the rapidly increasing angle of the ship caused passengers and crew to tumble against the walls, the furniture, and each other; passenger Margaret Mather recalled being hurled 15-20 feet against the rear wall of the dining room and being pinned against a bench by several other people.
The fire spread so quickly — consuming the ship in less than a minute — that survival was largely a matter of where one happened to be located when the fire broke out.
Passengers and crew members began jumping out the promenade windows to escape the burning ship, and most of the passengers and all of the crew who were in the public rooms on A Deck at the time of the fire — close to the promenade windows — did survive. Those who were deeper inside the ship, in the passenger cabins at the center of the decks or the crew spaces along the keel, generally died in the fire.
One passenger, John Pannes (the New York manager for the Hamburg-America Line, which handled passenger reservations for the Deutsche Zeppelin-Reederei), was in the dining room when the fire broke out; encouraged to jump by ship’s photographer Karl Otto Clemens, who escaped through one of the windows and survived, Pannes instead left the dining room to find his wife Emma, who had returned to their cabin for her coat. Both died in the fire.
Mr and Mrs Hermann Doehner and their three children (Irene, 16; Walter 10; and Werner, 8 ) were also in the dining room watching the landing, but Mr Doehner left before the fire broke out. Mrs Doehner and her two young sons jumped to safety, but Irene left the dining room in search of her father, and both died as a result of the crash.
Given the speed with which Hindenburg burned, survival for the crew was also largely a matter of luck. As the diagram below illustrates, those who were close to a means of exit at the time of the fire generally survived, including 9 of the 11 men in the engine cars, and 10 of the 12 men in the control car. Those who were deep inside the ship, such as the electricians in the power room along the keel, or Max Schulze in the smoking room bar on B Deck, or those on the starboard side (since the flaming ship rolled slightly to starboard as it hit the ground) were generally trapped in the wreck. And the men stationed in the bow — who were exposed to the column of flame that rose through the ship as the bow pointed skyward — had the least chance; the 9 men who were closest to the front of the ship at the time of the fire all died.
As the ship settled to the ground, less than 30 seconds after the first flames were observed, those who had jumped from the burning craft scrambled for safety, as did members of the ground crew who had been positioned on the field below the ship.
Natural instinct caused those on the ground to run from the burning wreck as fast as they could, but Chief Petty Officer Frederick J. “Bull” Tobin, a longtime airship veteran and an enlisted airship pilot who was in charge of the Navy landing party, cried out to his sailors: “Navy men, Stand fast!!” Bull Tobin had survived the crash of USS Shenandoah, and he was not about to abandon those in peril on an airship, even if it meant his own life. And his sailors agreed. Films of the disaster (see below) clearly show sailors turning and running back toward the burning ship to rescue survivors; those films are a permanent tribute to the courage of the sailors at Lakehurst that day.
Hindenburg left Frankfurt with 97 souls onboard; 62 survived the crash at Lakehurst, although many suffered serious injuries. Thirteen of the 36 passengers, and twenty-two of the 61 crew, died as a result of the crash, along with one member of the civilian landing party (Allen Hagaman).
The public seemed remarkably forgiving of the accident-prone zeppelin prior to the Hindenburg disaster, and the glamorous and speedy Hindenburg was greeted with public enthusiasm despite a long list of previous airship accidents.
But while airships like USS Akron (on which 73 died) crashed at sea, and the British R-101 (on which 48 were killed) crashed in the darkness of night — both far from witnesses or cameras — the crash of the Hindenburg was captured on film. Millions of people around the world saw the dramatic inferno which consumed the ship and its passengers. Oh, the Humanity!
At least, that’s the conventional wisdom about why the age of the zeppelin died that rainy day at Lakehurst.
But perhaps after 35 years of accidents and disasters — the crashes of LZ-4, LZ-5, Deutschland, Deutschland II, Schwaben, R-38, R-101, Shenandoah, Akron, Macon, and the list goes on — perhaps the public had just had enough.
And more importantly, despite its romance and grandeur, Hindenburg was obsolete before it ever flew.
On November 22, 1935 — three months before Hindenburg first took to the air — Pan American Airways’ M-130 China Clipper made the first scheduled flight across the Pacific. The M-130 could have crossed the Atlantic with ease; its 2,400-mile route San Francisco to Honolulu was longer than distance required to cross the North Atlantic. In fact, Pan Am’s M-130 was designed for the Atlantic, and it was only political (not technological) considerations that prevented Pan Am from inaugurating transatlantic airline service in 1935; the British refused to grant Pan Am landing rights until Britain had a plane that could make the same flight, but Britain was far behind America in the development of a long-distance airliner.
Between the cost of its infrastructure and crew, inherent safety issues, and the development of better technology, the rigid passenger airship was doomed long before Hindenburg landed at Lakehurst that fateful day in May.
More information about the Disaster: