LZ 127 Graf Zeppelin

LZ 127 Graf Zeppelin () was a German passenger-carrying hydrogen-filled rigid airship that flew from 1928 to 1937. It offered the first commercial transatlantic passenger flight service. The ship was named after the German airship pioneer Ferdinand von Zeppelin, a count () in the German nobility. It was conceived and operated by Hugo Eckener, the chairman of Luftschiffbau Zeppelin.

Graf Zeppelin made 590 flights totalling almost 1.7 million kilometres (over 1 million miles). It was operated by a crew of 36 and could carry 24 passengers. It was the longest and largest airship in the world when it was built. It made the first circumnavigation of the world by airship, and the first nonstop crossing of the Pacific Ocean by air; its range was enhanced by its use of Blau gas as a fuel. It was built using funds raised by public subscription and from the German government, and its operating costs were offset by the sale of special postage stamps to collectors, the support of the newspaper magnate William Randolph Hearst, and cargo and passenger receipts.

After several long flights between 1928 and 1932, including one to the Arctic, Graf Zeppelin provided a commercial passenger and mail service between Germany and Brazil for five years. When the Nazi Party came to power, they used Graf Zeppelin as a propaganda tool. The airship was withdrawn from service after the Hindenburg disaster in 1937 and scrapped for military aircraft production in April 1940.

Background

The first successful flight of a rigid airship, Ferdinand von Zeppelin's LZ1, was in Germany in 1900. Between 1910 and 1914, Deutsche Luftschiffahrts-Aktiengesellschaft (DELAG) transported thousands of passengers by airship. During World War I, Germany used airships to bomb London and other strategic targets. In 1917, the German LZ 104 (L 59) was the first airship to make an intercontinental flight, from Jambol in Bulgaria to Khartoum and back, a nonstop journey of .

During and just after the war, Britain and the United States built airships, and France and Italy experimented with confiscated German ones. In July 1919 the British R34 flew from East Fortune in Scotland to New York and back. Luftschiffbau Zeppelin delivered LZ 126 to the US Navy as a war reparation in October 1924. The company chairman Hugo Eckener commanded the delivery flight, and the ship was commissioned as .

The Treaty of Versailles placed limits on German aviation which the Allies relaxed in 1925. Eckener saw an opportunity to start an intercontinental air passenger service, and began lobbying the government for funds and permission to build a new civil airship. Public subscription raised (the equivalent of US$600,000 at the time, or $ million in 2018 dollars), and the government granted over ($ million).

Design and operation

thumb|left|upright|Construction of Graf Zeppelin in Friedrichshafen: the keel and axial gangways are highlighted green with main rings in red; two people are shown in yellow.|alt=Looking down the interior of a partially completed airship frame. Two passageways are highlighted; one along the bottom and one right through the middle. The closest two structural polygons are also highlighted; the cantilevers on the nearest one are visible. The two people in the foreground are barely visible.

The LZ 127 was designed by Ludwig Dürr as a "stretched" version of the zeppelin LZ 126 rechristened the USS Los Angeles). It was intended from the beginning as a technology demonstrator for the more capable airships that would follow. It was built between 1926 and September 1928 at the Luftschiffbau Zeppelin works in Friedrichshafen, on Lake Constance, Germany, which became its home port for nearly all of its flights. Its duralumin frame was made of eighteen 28-sided structural polygons joined lengthwise with of girders and braced with steel wire. The outer cover was of thick cotton, painted with aircraft dope containing aluminium to reduce solar heating, then sandpapered smooth. The gas cells were also cotton, lined with goldbeater's skins, and protected from damage by a layer containing of ramie fibre.

Graf Zeppelin was long and had a total gas volume of , of which was hydrogen carried in 17 lifting gas cells (Traggaszelle), and was Blau gas in 12 fuel gas cells (Kraftgaszelle). The Graf Zeppelin was built to be the largest possible airship that could fit into the company's construction hangar, with only between the top of the finished vessel and the hangar roof. It was the longest and most voluminous airship when built, but it was too slender for optimum aerodynamic efficiency, and there were worries that the shape would compromise its strength.

Graf Zeppelin was powered by five Maybach VL II 12-cylinder engines, each of capacity, mounted in individual streamlined nacelles arranged so that each was in an undisturbed airflow. The engines were reversible, and were monitored by crew members who accessed them during flight via open ladders. On a typical transatlantic journey, the Graf Zeppelin used Blau gas 90% of the time, only burning petrol if the ship was too heavy, and used ten times less hydrogen per day than the smaller zeppelin L 59 did on its Khartoum flight in 1917.

Graf Zeppelin typically carried of ballast water and of spare parts, including an extra propeller. Calcium chloride was added to the ballast water to prevent freezing. The ship retained grey water from the sinks for use as additional ballast. Both fresh and wastewater could be moved forward and aft to control trim.

thumb|right|One of the engine nacelles, preserved in [[Zeppelin Museum Friedrichshafen|alt=A dilapidated egg-shaped streamlined nacelle on display in a museum. The pointed end is towards the camera and has a large adjustable rectangular vent.]]

The airship usually took off vertically using static lift (buoyancy), then started the engines in the air, adding aerodynamic lift. Normal cruising altitude was ; it climbed if necessary to cross high ground or poor weather, and often descended in stormy weather. To measure the wind speed over the sea, and calculate drift, floating pyrotechnic flares were dropped.

When preparing to land, the crew advised the ground either by radio or signal flag. Ground crew lit a smoky fire to help the airshipmen judge wind speed and direction. The airship slowed, then adjusted buoyancy to neutral by valving off hydrogen or dropping ballast. Echo sounding with the report from an 11-mm blank round was used to measure altitude accurately. Up to 300 people manhandled the airship into a hangar or secured it by the nose to a mooring mast.

Graf Zeppelin<nowiki>'</nowiki>s top airspeed was at ; it cruised at , at . It had a total lift capacity of with a usable payload of on a flight. It was slightly unstable in yaw, and to make it easier to fly, had an automatic pilot which stabilised it in that axis. Pitch was controlled manually by an elevatorman who tried to limit the angle to 5° up or down, so as not to upset the bottles of wine which accompanied the elaborate food served on board. Operating the elevators was so demanding and strenuous that an elevatorman's shift was only four hours, reduced to two in rough weather.

Layout

thumb|center|upright=1.75|Gondola deck plan|alt=A plan of the airship's gondola accommodation, as described in the text.

The operational spaces, common areas, and passenger cabins were built into a gondola structure in the forward part of the airship's ventral surface, with the flight deck well forward in a "chin" position. The gondola was long and wide; its streamlined design reflected contemporary aesthetics, minimised overall height, and reduced drag. Behind the flight deck was the map room, with two large hatches to allow the command crew to communicate with the navigators, who could take readings with a sextant through the two large windows. Also along this corridor were petrol, oil and water tanks, and stowage for cargo and spare parts. Branches from the keel corridor led to the five engine nacelles, and there were ladders up to the axial corridor, just below the ship's main axis, which gave access to all the gas cells.

Electrical and communications systems

thumb|right|Many people were needed to hold down the airship. The [[ram air turbine electric generator is just under the radio room window.|alt=The gondola while the airship is being manoeuvred on the round. Around forty people on the ground are manhandling it. Two officers are visible in the gondola, one looking down at the people, the other looking backwards. The ram air turbine is folded flush with the gondola's side.]]

The main generating plant was in a separate compartment mostly inside the hull. Two Wanderer car engines adapted to burn Blau gas, only one of which operated at a time, drove two Siemens & Halske dynamos each. One dynamo on each engine powered the oven and hotplates, and one the lighting and gyrocompass. Cooling water from these engines heated radiators inside the passenger lounge. Two ram air turbines attached to the main gondola on swinging arms provided electrical power for the radio room, internal lighting, and the galley. Batteries could power essential services like radios for half an hour, and there were small petrol generators for emergency power.

Three radio operators used a one-kilowatt vacuum tube transmitter (about 140 W antenna power) to send telegrams over the low frequency (500–3,000 m) bands. During most of its career, it was operated by Luftschiffbau Zeppelin's commercial flight arm, DELAG, in conjunction with the Hamburg-American Line (HAPAG); for its final two years it flew for the Deutsche Zeppelin Reederei (DZR).

Passengers paid premium fares to fly on the Graf Zeppelin ( from Germany to Rio de Janeiro in 1934, equal to US$590 then, or $ in ), and fees collected for valuable freight and air mail also provided income. On the first transatlantic flight, Graf Zeppelin carried 66,000 postcards and covers.

Eckener had earned his doctorate in Psychology at Leipzig University under Wilhelm Wundt, and could use his knowledge of mass psychology to the benefit of the Graf Zeppelin. He identified safety as the most important factor in the ship's public acceptance, and was ruthless in pursuit of this. He took complete responsibility for the ship, from technical matters, to finance, to arranging where it would fly next on its years-long public relations campaign, in which he promoted "zeppelin fever". On one of the Brazil trips British Pathé News filmed on board. Eckener cultivated the press, and was gratified when the British journalist Lady Grace Drummond-Hay wrote, and millions read, that:

Graf Zeppelin was greeted by large crowds on most of its early voyages. There were 100,000 at Moscow and possibly 250,000 at Tokyo to see it. At Stockholm, spectators launched firework rockets around it, and on the return flight from Moscow it was punctured by rifle shots near the Soviet Union-Lithuania border. On one visit to Rio de Janeiro people released hundreds of small toy petrol-burning hot air balloons near the flammable craft. The airship captured the public imagination and was used extensively in advertising. On visits to England, it photographed Royal Air Force bases, the Blackburn aircraft factory in Yorkshire, and the Portsmouth naval dockyard; it is likely that this was espionage at the behest of the German government.

Proving flights

During 1928, there were six proving flights. On the fourth one, Blau gas was used for the first time. Graf Zeppelin carried Oskar von Miller, head of the Deutsches Museum; Charles E. Rosendahl, commander of USS Los Angeles; and the British airshipmen Ralph Sleigh Booth and George Herbert Scott. It flew from Friedrichshafen to Ulm, via Cologne and across the Netherlands to Lowestoft in England, then home via Bremen, Hamburg, Berlin, Leipzig and Dresden, a total of in 34 hours and 30 minutes. On the fifth flight, Eckener caused a minor controversy by flying close to Huis Doorn in the Netherlands, which some interpreted as a gesture of support for the former Kaiser Wilhelm II who was living in exile there.

First intercontinental flight (1928)

thumb|right|Graf Zeppelin in Lakehurst, with damage to the port fin after hitting a squall line, 16 October 1928

thumb|right|A piece of the damaged fabric removed from Graf Zeppelin in October 1928|alt=A piece of badly distressed fabric on a red background. The fabric is crossed by three seams and there are three eyelets at the bottom of it.

In October 1928, Graf Zeppelin made its first intercontinental trip, to Lakehurst Naval Air Station, New Jersey, US, with Eckener in command and Lehmann as first officer. Rosendahl and Drummond-Hay flew the outward leg. Ludwig Dettmann and Theo Matejko made an artistic record of the flight.

On the third day of the flight, a large section of the fabric covering of the port tail fin was damaged while passing through a mid-ocean squall line, and volunteer riggers (including Eckener's son, Knut) climbed outside the airship and made repairs to the torn fabric. Eckener directed Rosendahl to make a distress call; when this was received, and nothing else was heard from the airship, many believed it was lost. After the ship arrived safely, there was some annoyance from the Lakehurst personnel that the Zeppelin had not answered repeated calls for its position and estimated arrival time. Eckener explained that because the airship was forced to fly at a reduced speed due to the damaged fin, the wind-driven generator could not generate enough power to send messages. The crossing, the longest non-stop flight at the time, had taken 111 hours 44 minutes.

Clara Adams became the first female paying passenger to fly transatlantic on the return flight. The ship endured an overnight gale that blew it backwards in the air and off course, to the coast of Newfoundland. A stowaway boarded at Lakehurst and was discovered in the mail room mid-voyage. The airship returned home and on 6 November flew to Berlin Staaken, where it was met by the German president, Paul von Hindenburg.

Mediterranean flights (1929)

thumb|right|Graf Zeppelin over Jerusalem on 26 March 1929

Graf Zeppelin visited Mandatory Palestine in late March 1929. At Rome it sent greetings to Benito Mussolini and King Victor Emmanuel III. It entered Palestine, flew over Haifa, Jaffa, Tel Aviv and Jerusalem, and descended to near the surface of the Dead Sea, 150 metres below sea level. The ship delivered 16,000 letters in mail drops at Jaffa, Ramla, Athens, Budapest and Vienna. The Egyptian government (under pressure from Britain) refused it permission to enter their airspace. The second Mediterranean cruise flew over France, Spain, Portugal and Tangier, then returned home via Cannes and Lyon on 23–25 April.

Forced landing in France (1929)

thumb|left|Emergency landing in France, May 1929|alt=A black-and-white photograph from under the airship's hull while on the ground. In the right middle ground a crewman wearing a leather cap is leaning out of one of the engine nacelles. The wooden grain is visible in the two-bladed propeller, which is stationary and horizontal. The rear engine nacelle is visible and the bottom of the fin. Around 30 people are visible, and about 10 are around the rear nacelle. One man is walking briskly towards the camera. In the background are two large hangars, of unequal size.

On 16 May 1929, on the first night of its second trip to the US, Graf Zeppelin lost four of its engines. With Eckener struggling for a suitable place to force-land, the French Air Ministry allowed him to land at Cuers-Pierrefeu, near Toulon. Barely able to control the ship, Eckener made an emergency landing. The incident, and the forced comradeship it engendered, softened France's attitude to Germany and its airships slightly. The incident was caused by adjustments that had been made by the chief engineer to the four engines that failed.

On 4 August, the airship made it to Lakehurst on the second attempt. Aboard was Susie, an eastern gorilla who had been captured near Lake Kivu in the Belgian Congo and sold by her German owner to an American dealer.

Round-the-world flight (1929)

thumb|right|Graf Zeppelin and [[USS Los Angeles (ZR-3)|USS Los Angeles in the airship hangar at NAS Lakehurst, August 1929]]

thumb|right|Drummond-Hay on board the Graf Zeppelin, August 1929

thumb|right|Graf Zeppelin over Tokyo on 19 August 1929

American newspaper publisher William Randolph Hearst's media empire paid half the cost of the project to fly Graf Zeppelin around the world, with four staff on the flight: Lady Hay Drummond-Hay, Karl von Wiegand, Australian explorer Hubert Wilkins, and cameraman Robert Hartmann. Drummond-Hay became the first woman to circumnavigate the world by air.

Hearst stipulated that the flight in August 1929 officially start and finish at Lakehurst. Round-the-world tickets were sold for almost $3000 (), but most participants had their costs paid for them. The flight's expenses were offset by the carriage of souvenir mail between Lakehurst, Friedrichshafen, Tokyo, and Los Angeles. A US franked letter flown on the whole trip from Lakehurst to Lakehurst required $3.55 () in postage.

Graf Zeppelin set off from Lakehurst on 8 August, heading eastwards. The ship refuelled at Friedrichshafen, then continued across Eastern Europe and the Soviet Union to Tokyo. On 19 August, LZ 127 arrived in Tokyo. Among the passengers were Werner Heisenberg and Paul Dirac, who gave scientific lectures there in September.

After five days at a former German airship shed that had been removed from Jüterbog and rebuilt at Kasumigaura Naval Air Station, Graf Zeppelin continued across the Pacific to California. Eckener delayed crossing the coast at San Francisco's Golden Gate so as to come in near sunset for aesthetic effect. The ship landed at Mines Field in Los Angeles, completing the first ever nonstop flight across the Pacific Ocean. The takeoff from Los Angeles was difficult because of high temperatures and an inversion layer. To lighten the ship, six crew and some cargo were sent on to Lakehurst by aeroplane. The airship suffered minor damage from a tail strike and barely cleared electricity cables at the edge of the field. It was the fastest circumnavigation of the globe at the time.

Eckener became the tenth recipient and the third aviator to be awarded the Gold Medal of the National Geographic Society, which he received on 27 March 1930 at the Washington Auditorium. Before returning to Germany, Eckener met President Herbert Hoover, and successfully lobbied the US Postmaster General for a special three-stamp issue (C-13, 14 & 15) for mail to be carried on the Europe-Pan American flight due to leave Germany in mid-May. Germany issued a commemorative coin celebrating the circumnavigation.

Europe-Pan American flight (1930)

thumb|right|$2.60 [[1930 Graf Zeppelin stamps|Europe-Pan American issue (C-15), 24 April 1930|alt=A rectangular postage stamp, torn from a perforated sheet. It is in landscape format and is printed with blue ink on a white background. At the top it says "Graf Zeppelin: Pan-American Flight" and on the bottom "$2.60 United States Postage $2.60". In between is a depiction of the airship, flying from right to left, against a background of the planet Earth. Stylised clouds swim across the scene, and rays of sunlight are shining in from the top-left corner.]]

On 26 April 1930, Graf Zeppelin flew low over the FA Cup Final at Wembley Stadium in England, dipping in salute to King George V, then briefly moored alongside the larger R100 at Cardington. It then flew to Rio de Janeiro, where there was no post to tether to, so it was held down by the landing party for the two hours of the visit. A few hours from home, when the Graf Zeppelin flew through a heavy hailstorm over the Saône, the envelope was damaged, and the ship lost lift. Eckener ordered full power and flew the ship out of trouble, but it came within of hitting the ground.

The Europe-Pan American flight was largely funded by the sale of special stamps issued by Spain, Brazil, and the US for franking mail carried on the trip. The US issued stamps in three denominations: 65¢, $1.30, and $2.60, all on 19 April 1930.

Middle East flight (1931)

The second flight to the Middle East took place in 1931, beginning on 9 April. Graf Zeppelin crossed the Mediterranean to Benghazi in Libya, then flew via Alexandria, to Cairo in Egypt, where it saluted King Fuad at the Qubbah Palace, then visited the Great Pyramid of Giza and hovered above the top of the monument. There was a large community of Germans in Brazil, and existing sea connections were slow and uncomfortable. Graf Zeppelin could transport passengers over long distances in the same luxury as an ocean liner, and almost as quickly as contemporary airliners.

Graf Zeppelin made three trips to Brazil in 1931 and nine in 1932. The route to Brazil meant flying down the Rhône valley in France, a cause of great sensitivity between the wars. The French government, concerned about espionage, restricted it to a -wide corridor in 1934. Graf Zeppelin was too small and slow for the stormy North Atlantic route, but because of the Blau gas fuel, could carry out the longer South Atlantic service. On 2 July 1932 it flew a 24-hour tour of Britain. and was used four times by Graf Zeppelin and five by Hindenburg. It now houses units of the Brazilian Air Force. The airships flew in tandem around Germany before the vote, with a joint departure from Löwenthal on the morning of 26 March. They toured the country for four days and three nights, dropping propaganda leaflets, playing martial music and slogans from large loudspeakers, and broadcasting political speeches from a makeshift radio studio on Hindenburg.

Retirement and aftermath

thumb|right|Graf Zeppelin flying over Germany later in its career, with swastikas on the tail fins|alt=A black-and-white photograph from slightly above of the Graf Zeppelin, a large slim airship, flying from right to left against a low sun. The ground below is misty and consists of rolling hills, woods, and a meandering road which is catching the sun. The silvery airship is also reflecting the sun. It bears black swastikas on white circles on its vertical tail surfaces.

The crew heard of the Hindenburg disaster by radio on 6 May 1937 while in the air, returning from Brazil to Germany; they delayed telling the passengers until after landing on 8 May so as not to alarm them. The disaster, in which Lehmann and 35 others were killed, destroyed public faith in the safety of hydrogen-filled airships, making continued passenger operations impossible unless they could convert to non-flammable helium. Hindenburg had originally been planned to use helium, but almost all of the world's supply was controlled by the US, and its export had been tightly restricted by the Helium Act of 1925.

Graf Zeppelin was permanently withdrawn from service shortly after the disaster. On 18 June, its 590th and last flight took it to Frankfurt am Main, where it was deflated and exhibited to visitors in its hangar. President Roosevelt supported exporting enough helium for the Hindenburg-class LZ 130 Graf Zeppelin II to resume commercial transatlantic passenger service by 1939, but by early 1938, the opposition of Interior Secretary Harold Ickes, who was concerned that Germany was likely to use the airship in war, made that impossible. On 11 May 1938, Roosevelt's press secretary announced that the US would not sell helium to Germany. Eckener, who had unsuccessfully intervened, responded that it would be "the death sentence for commercial lighter-than-air craft."

Modern airships like the Zeppelin NT use semi-rigid designs and are lifted by helium on their mainly sight-seeing duties.

Specifications

thumb|right|upright=2|Internal components and gas cell locations shown schematically, excluding passenger and engine gondolas

References

Notes

Citations

Bibliography

External links

British Pathe video clips
San Diego Air & Space Museum: Henry Cord Meyer Collection, Flickr