LZ 130 Graf Zeppelin II

This article is about the second airship. For other meanings, see Graf Zeppelin.
Graf Zeppelin
Other name(s) Graf Zeppelin II
Type Hindenburg-class airship
Manufacturer Luftschiffbau Zeppelin
Construction number LZ 130
Manufactured 1936-38
Registration D-LZ130
First flight 14 September 1938
In service 1938–40
Flights 30
Fate Broken up April 1940
Preserved at Zeppelin Museum Friedrichshafen (bow)

The Graf Zeppelin II (Deutsche Luftschiff Zeppelin #130; Registration: D-LZ 130) was the last of the great German rigid airships built by the Zeppelin Luftschiffbau during the period between the World Wars, the second and final ship of the Hindenburg class named in honor of Paul von Hindenburg. The airship, which made 30 flights over 11 months in 1938–39 before being scrapped in 1940, was the second zeppelin to carry the name "Graf Zeppelin" (after the LZ 127) and thus is often referred to as Graf Zeppelin II.

Design and development

The Graf Zeppelin II was nearly identical to the Hindenburg, and originally designed to use hydrogen as lifting gas. After the Hindenburg disaster, however, Hugo Eckener vowed never to use hydrogen alone in a passenger airship again. The only source of helium in large enough quantities was in the United States, so Eckener went to Washington, D.C. to lobby for helium for his airships. He visited President Roosevelt himself, who promised to supply helium, but only for peaceful purposes. After the annexation of Austria in March 1938, U.S. Secretary of the Interior Harold Ickes refused to supply helium, and the Graf Zeppelin II was ultimately filled with hydrogen.

The design of LZ-130 incorporated a few improvements over the design of the LZ 129 Hindenburg. Initially, the engine cars were designed and installed to have same pusher configuration as the Hindenburg. After the Hindenburg disaster, however, the engine pods were completely redesigned and reinstalled, using diesel engines powering tractor propellers. These new pods were better insulated than those used on the Hindenburg and engine noise was noticeably quieter. In later flights, the airship used three-bladed propellers on both of its rear engines; trials were run on the forward port engine car as the ship neared completion, but only the aft-port engine car had a three-bladed propeller on its first flight. Unlike the wooden propellers of the Hindenburg, which had problems with moisture absorption causing imbalance, these three-bladed propellers were made of plastic wood and individual blades were assembled onto a main hub. The engines had a water recovery system which captured the exhaust of the engines, recovering water vapor present in the exhaust gases and condensing it for storage in tanks aboard the airship, to compensate for the fuel's weight lost during flight.

Model reconstruction of LZ 130 "Graf Zeppelin" (II) featuring tractor propellers. Note that the position of the engine cars and passenger deck is incorrect in this model.

The passenger decks were also completely redesigned to accommodate 40 passengers, compared to the Hindenburg's 72. The restaurant was moved to the middle of the quarters and the promenade windows were half a panel lower. The cabins would be more spacious and had better lighting compared to those of the Hindenburg; four of these were luxury cabins. The 16 gas cells were lightened and one was made of lightweight silk instead of cotton. The tail fins were slightly shorter and the number of intermediate ribs was reduced to save weight and reduce stress on the trailing edge of the fin. The lower fin had an upward curve similar to the Hindenburg's final design (after the fin was damaged during a propaganda flight). Other redesigns included the gas vent hoods, gondola windows and the landing wheel design. On the bow there were just two windows, as with the Hindenburg's original design (in the Hindenburg more windows were later fitted after its test flights). The German investigation on the Hindenburg Disaster suggested the poor conductivity of the Hindenburg's outer skin played a role in the ignition of hydrogen. As a result, the cords connecting the panels were treated with graphite to increase the outer covering's electrical conductivity. These changes were little-known and politically suppressed in fear of embarrassment for such a design flaw.

Construction time line

23 June 1936 – The keel of the airship was laid and the main rings were fastened onto the roof of the hangar.

14 February 1937 – The nose cone was installed. In the same month, the fabric was also applied over the framework.

6 May 1937 – The LZ 129 Hindenburg bursts into flames and crashes while landing at Lakehurst, NJ, killing 35 out of 97 people on board and one member of the ground crew. Although the LZ 130 was planned to be launched later in the year, the disaster prompted several redesigns of the airship, such that its construction would be further delayed.

15 August 1938 – Inflation began on gas cells.

20 August 1938 – Engines and electrical connections are tested.

22 August 1938 – The radio communication system is tested.

14 September 1938 – The ship was christened and flew the first time. Only Zeppelin Company officials and Hermann Göring were present; no other government representatives came to the christening to congratulate Eckener. The speech was held by Dr. Eckener.

14 November 1938 – By the time the Graf Zeppelin II was completed, it was obvious that the ship would never serve its intended purpose as a passenger liner; the lack of a supply of inert helium was one cause. The Reich Air Ministry permitted the Graf Zeppelin to fly "for one year until 1 September 1939 without any transportation of passengers and outside from tropical areas”.

Operational history

In total, the Graf Zeppelin made thirty flights:[1]

Flights 1 to 7

1. 14 September 1938 – The maiden voyage took place immediately after the christening of the ship under the command of Dr. Hugo Eckener. The ship took off from Friedrichshafen at 7:50 AM with 74 people mainly Air Ministry, and Zeppelin Company officials on board. Also on board were the builders, technicians and engineers of the airship. The engines were only started after the airship reached a height of approximately 100 m. The Graf Zeppelin flew across Munich, Augsburg and Ulm and returned to Friedrichshafen at 1:30 PM, travelling a total of 925 kilometres. Hugo Eckener described the trip as "satisfying" and "successful."

2. 17–18 September 1938 – The second trip was a 26-hour test trip under the command of Dr. Hugo Eckener and Captain Hans von Schiller with a total of 85 persons on board. It started at 8:08 AM on 17 September 1938. The morning was spent over the Bodensee with different measurements. At noon the ship flew north towards Stuttgart at 12:15 and Frankfurt am Main at 13:15, and then towards Eisenach and Eisleben. Towards evening Berlin was reached. After many circuits at low altitude the Graf started towards Hamburg. Over the outer-Elbe-estuary in the Wadden Sea further calibrations and tests were made. Afterwards it flew a direct course over Minden towards Frankfurt am Main and then towards Bodensee. There, the airship had to fly a large loop over Friedrichshafen, because the airfield lay in fog. At 10:17, LZ 130 landed after covering 2,388 km, and shortly before 11 o'clock was brought back into the Löwenthaler hangar.

3. 22 September 1938 – The third trial flight; 8:13–19:30 1215-km loop over Munich and Vienna and back again.

4. 25 September 1938 – Launch approx. 11:00 under Captain Hans von Schiller (duration approx. 7 h, 764 km, 40 crew members, 34 passengers and technicians). Tests at high altitude were made. Almost the whole trip took place at an altitude of about 2,000 m, without needing to valve much gas. Further atmospheric-electrical tests were made.

5. 27 September 1938 – eleven hours of trip duration, on behalf of the Reich Air Ministry (RLM). At the airport and airship-port Rhein-Main a radio beacon was set up. The idea was to attempt a Funkbeschickung (a calibration of the direction-finding equipment). Hazy air hindered the attempts despite good weather conditions. The calibration did not succeed perfectly – these problems arose even at later attempts. There were also first successes with the Ballastwassergewinnungsanlage (a water recovery system to save ballast). Three and a half tonnes of ballast water could be saved and the engines ran quieter because of the sound-absorbing effect of the device.

6 28 September 1938 – Further test flight on behalf of the RLM under Captain Sammt. Among other things, the test was intended to investigate whether electrostatic charges caused the Hindenburg disaster. Therefore, it was especially flown during thunderstorms. Flights during normal weather conditions brought no useful results. The ship was flown into the stormfront slack (gas cells under-expanded), to prevent the over-pressure valves releasing hydrogen. The trip lasted nearly 26 hours; covering over 2,500 km. The ballast water recovery system fulfilled the engineers' expectations by producing about nine tons of water.

7. 31 October 1938 – Launch around 2:15 under the command of Captain Sammt. This was simultaneously the last inspection flight and the transfer flight to Flug- und Luftschiffhafen Frankfurt am Main (the airship port at Frankfurt am Main). It landed after nearly 25 hours, covering over 2,100 km around 15:10. The airship and the crew were welcomed by Gauleiter Sprenger at the new home port. After this trip LZ 130 on 14 November 1938 received the Luftschiff-Zulassungsschein (airship registration document). Thus it was certified for air traffic and registered in the German Luftfahrzeugrolle (aircraft register), however with the restriction of no carriage of passengers.

Flight 8 – Sudetenlandfahrt

Post card carried from Frankfurt (Rhein-Main) to Reichenberg (Sudetengau) on the "Sudetenduetsch Freiheitsfahrt 1938" on the first mail flight of the "Graf Zeppelin II" (DLZ130), December 1–2, 1938

8. “Sudetenlandfahrt” ("Sudetenland journey") also known as the Sudetendeutsche Freiheitsfahrt 1938, was made at the behest of the Reich Ministry for Public Enlightenment and Propaganda (Reichsministerium für Volksaufklärung und Propaganda or Propagandaministerium). After the popular vote resulted in a large majority for Hitler and the National Socialist Party many propaganda channels were used – including a Zeppelin flight over the befreiten Gebiete ("liberated regions"). On board were 62 crew members and 7 passengers, among them military officers. Taking off on 2 December 1938, LZ130 arrived over Reichenberg (present-day Liberec), capital of Sudetenland (a German-speaking area in Czechoslovakia), timed to match Hitler's visit. Small parachutes were thrown out with swastika flags and handbills carrying the text "Dein JA dem Führer!" ("Your YES for the leader"). LZ 130's loudspeakers played music and National Socialist propaganda for the forthcoming December 4 elections. Afterwards LZ 130 flew to the Reichenberg airfield and dropped 663 kg of postally cacheted souvenir mails. Worsening weather hindered further flight, and after some time it was decided to turn back. After the ship left the Sudetenland, it came into low cloud and snow showers. It started to ice up. Later, the propellers blew broken-off ice shards through the ship's outer envelope. However, the crew immediately repaired the damage. The Zeppelin landed without problem in gusty winds at 17:46 and was brought into the airship hangar.

Flights 9 to 23

9. 13 January 1939 launched at 9:08, commanded by captain Sammt, different tests were performed. Duration: 7 hours and 523 km

10. 13 April 1939 Among other things, radio- and spy basket tests were performed. In a flight lasting approximately 30 hours it covered nearly 2,700 km (1,700 mi)

11. 15 June 1939 Duration: 28 hours; 2,800 km

12. and 13. Meiningenfahrt 2 July 1939 ; 18:40 landing at Meiningen airfield, flew back to Frankfurt am Main at 19:22.

14. and 15. Leipzigfahrt (Leipzig trip) 9 July 1939; among other things landing in Leipzig-Mockau airfield with post office delivery

16. Nordseefahrt (North Sea trip) 12 July 1939. Launch: 22:25

17. and 18. Görlitzfahrt (Görlitz trip) launch: 16 July 1939 00:34 under captain Sammt

19. 20., and 21. Bielefeld-Münster-Fahrt (Bielefeld-Münster trip): 23 July 1939

22. and 23.:To Kassel: 30 July 1939

Flight 24 – Spionage

24. The Spionage ("espionage trip") of 2 to 4 August 1939, taking over 48 hours and covering 4,203 km (2,612 mi), was the longest trip the LZ 130 made. The main goal was to secretly collect information on the British Chain Home radar system.[2] To do this the airship flew northwards close to the British east coast up to the Shetland Isles and back. As well as the 45 crew, 28 personnel engaged in the measurements were carried. Lifting off was around 20:53 on 2 August 1939, it overflew Hildesheim at 23:38, seen by very few people.[2]

According to the memoirs of Albert Sammt, Mein Leben für den Zeppelin (translation: "My life for the zeppelin") in the chapter Mit LZ 130 Graf Zeppelin auf Funkhorch- und Funkortungsfahrt ("with the LZ 130 Graf Zeppelin on the radio-listening and radiolocation trip") a radio-measuring spy basket was used. He flew the LZ 130 up Britain's east coast stopping the engines at Aberdeen pretending they had engine failure in order to investigate strange antenna masts. They drifted freely westwards over land and saw for the first time the new Supermarine Spitfires, which were then photographed as they circled the airship.[3]

On their return journey, as they neared Frankfurt on the evening of 4 August they were warned by radio that landing was not yet possible. At first they suspected an aeroplane had crashed at the site, but on overflying saw nothing amiss. They turned and flew towards the Rhön Mountains and on asking, were informed "landing before dusk not possible". They decided to return to Frankfurt and speak directly with the landing team (Landemannschaft) using their Very high frequency transmitter, so that they would not be overheard by the French and so that they could speak in Swabian German to Beurle, the landing team leader.[3]

Beurle informed them they must not land yet because the British had lodged a diplomatic protest over their actions and a British delegation was at the airfield, with agreement of the German government, to inspect the ship. They were under suspicion. Beurle told them to wait while they thought of something.[3]

Shortly, the LZ 130 received instructions. They were to hide all the equipment on the ship and not to land at the usual well-lit landing point where a landing team was waiting, but to land at the other end where the "real" landing team was waiting. Once they had landed there, the technicians were to get off and they would be replaced by a unit of Sturmabteilung.

The British delegation waiting at the usual landing place were told that, due to the weather, the airship had to land at another part of the airfield. By the time the British reached the airship, the spy crew was on a bus on their way to their hotel. Although they searched the ship, the British found nothing suspicious on the ship nor in the decoy SA-crew.[3]

Dr. Breuning explained that the trip's results were negative, and not because the British radar was switched off, as Churchill wrote in his memoirs. The German General Wolfgang Martini used a strong, impulsive, broadband radio transmission for determining the "radio-weather", the best wavelengths to use for radio. These impulses severely disturbed the highly sensitive receivers in the 10-12 metre waveband. Dr. Ernst Breuning wrote that he repeatedly requested Martini to stop transmitting during the spy trips, to no avail. This made it impossible for the LZ 130 to investigate the very wavebands the British were using.[3]

Flights 25 to 30

25. and 26. Würzburgfahrt (Würzburg trip) 6 August 1939

27. and 28. Egerfahrt (Eger trip) 13 August 1939

29 and 30. The last trip, the so-called Essen/Mülheim-Fahrt (Essen/Mülheim trip), took place on 20 August 1939. The departure and destination was Frankfurt am Main with an intermediate stop at Essen/Mülheim Airport, commanded by Albert Sammt. This trip (landing at 21:38) meant the end of large airship transport. The Graf Zeppelin II was grounded with its gas cells and equipment removed, until it was dismantled in April 1940.

The end of the Zeppelins

In April 1940, Hermann Göring issued the order to scrap both Graf Zeppelins and the unfinished framework of LZ 131, since the metal was needed for other aircraft. By April 27, work crews had finished cutting up the airships. On May 6, the enormous airship hangars in Frankfurt were leveled by explosives, three years to the day after the destruction of the Hindenburg.

Specifications (LZ129 Hindenburg class)

Note: The LZ130 Graf Zeppelin II was similar in most respects

Data from [4]

General characteristics

Performance

See also


Related lists

Notes

  1. ↑ Sammt, Albert (1994). Mein Leben für den Zeppelin. Pestalozzi. ISBN 978-3921583029. Flight Log in Japanese
  2. 1 2 Schütz, Michael. Zeppeline über Hildesheim, Hildesheim city archive. Last accessed 2008-08-02
  3. 1 2 3 4 5 Sammt 1988
  4. ↑ Brooks, Peter W. (1992). Zeppelin: Rigid Airships 1893–1940 (1st ed.). London: Putnam & Company Ltd. pp. 174–185. ISBN 9780851778457.

References

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