ZPG-2W 1958

Die ZPG-2 und ZPG-2W-Luftschiffe waren US-Marine-Luftschiffe, die zu Patroulliezwecken kurz nach dem Zweiten Welkrieg gebaut wurden. Insgesamt wurden zwölf Schiffe dieses Typs eingesetzt. Sie gehörten von 1954-1962 zum Luftangriffs-Frühwarnsystem der USA im Kalten Krieg. Die Airship Airborne Early Warning Squadron 1 (ZW 1) schloss die Lücke zwischen den Radarposten auf Schiffen der US-Marine ("DER" Radar Picket Destroyer Escort) an der sogenannten "Anschlussbarriere" (Contiguous Barrier) und den landgestützen Radarstationen der "Küstenbarriere" (Inshore Barrier).

Geschichte Bearbeiten

Der Erstflug fand am 20. März 1950 statt.

Fünf der zwölf Schiffe wurden von Goodyear neu gebaut, die restlichen wurden aus

Das erste ZPG-2W wurde im Mai 1955 nach Lakehurst geliefert [1]

Einsatz Bearbeiten

Im Januar 1957 besetzten die Luftschiffe 10 Tage ununterbrochen auf ihrem Posten 200 Meilen vor der Küste, in einer Wetterlage, die als schlimmstes Wetter seit 75 Jahren bezeichnet wurde.[2]

März 1957: 11 Tage airborne ohne Auftanken[2]

die Heimatbasis war Lakehurst.

Die Luftschiffe wurden 1962 mit dem Ende des US-Marine-Luftschiffprogramms außer Dienst gestellt.

Weiterentwicklung Bearbeiten

1957 wurde bekanntgegeben, dass ein ZPG-2W mit einer internen Radarantenne modifiziert wurde. Somit entstand damit das bis dahin größe luftgestützte Suchradar.[2] Diese Anordnung der Suchradarantenne sollte beim Nachfolger ZPG-3W zum Standard werden. Zuvor hing die Suchradarantenne unter der Gundel.


Technik Bearbeiten

Das Luftschiff verfügte über eine elektronische Ausrüstung zur Frühwarnung vor feindlichen Flugkörpern. Dazu zählte ein großer Radardom oben auf der Hülle, der eine Radaranlage zur Höhenbestimmung enthielt und eine weitere Radarantenne unterhalb der Gondel.

Außergewähnlich war die damalige Anordnung der Leitwerksflossen. Sie war X-förmig, im Gegensatz zu der sonst üblichen vertikal/kreuzförmigen Bauweise. Mit dieser Anordnung wurde eine deutlich höhere Bodenfreiheit am Heck erreicht, was vor allem bei Starts, die auf Grund des hohen Startgewichts mit angehobenem Bug erfolgten, vorteilhaft war.

Die 25,3 m (83 ft) lange Gondel verfügte über zwei Decks. Unten waren die Cockpit, Flugstationen und Radarbediener, oben die Kombüse, Messe und Schlafquartiere. Die Offiziere hatten eine eigene Kammer, in der voll ausgestatteten Küche war unter anderem ein Kühlschrank und eine fest installierte Kaffeemaschine vorhanden. Zwei mit Kraftstoff betriebene von den Triebwerken unabhängige Heizungen ermöglichten unterschiedliche Temperatureinstellungen für das Ober- und Unterdeck.

Eine Besonderheit gegenüber den Vorgängern der K-Klasse waren die innerhalb der Gondel angeordneten Triebwerke. Hintergrund war die Kopplung beider Motoren und Propeller über Wellen. So war es auch möglich das Luftschiff mit nur einem Motor zu betreiben um Kraftstoff zu sparen. Die Triebwerke waren mit einem Feuerlöschsystem ausgestattet. Die Dreiblatt-Zugpropeller verfügten über eine Enteisungsanlage.

Die Krafstofftankanlage bestand aus einem System mehreren fest installierter und im Notfall abwerfbarer Tanks in der Gondel. Die Luftschiffe verfügten zusätzlich über Aufnahmen für Standard-Flugzeug-Abwurftanks an der Hülle um die Einsatzdauer noch weiter steigern zu können. Außerdem konnte die Luftschiffe auf See betankt werden.

  • Volumen: 975,000 cubic foot mit 4 Ballonetts (wobei die beiden mittleren gekoppelt waren) die etwa 25 % des Volumen einnehmen konnten. Der Druck zum prall halten der Ballonets stammte aus Staulufteinlässen in den Auslegern hinter den Propellern oder wurde zusätzlich mittels elektrischen Gebläsen auf Druck erzeugt.
  • Antrieb: 2x800 PS Wright Cyclone 7-Motoren, die über eine internes Hilfstriebwerk gestartet werden konnten.
  • Gesamtlänge: 104,5 m (343 ft)
  • Durchmesser: 22,9 m (75ft)
  • Höchstgeschwindigkeit: 80 mph
  • Besatzung: üblicherweise 14-17 Personen
  • Traggas: Helium
  • Fahrwerk: ein für Luftschiffe sehr unübliches hydraulisch einziehbares Dreipunkt-Burgradfahrwerk mit je einem Fahrwerksbein unter dem Cockpit und in den Mororgondeln. Diese Ausführung ist mutmaßlich der freien Rundumsicht Des Suchradars unter der Gondel geschuldet.

Bewaffnung (ZPG-2)

  • Sonarbojen
  • Schleppsonar
  • Topedos und Wasserbomben

Rekordfahrten Bearbeiten

Im Mai 1954[3] stellte ein ZPG-2W unter dem Kommandanten M. Henry Eppes mit einer Fahrt von 200,2 Stunden ohne Auftanken einen Dauerfahrtrekord für Luftschiffe auf, der jedoch nicht offiziell von der FAI anerkannt wurde. Dieser Wert wurde noch übertroffen von der ebenfalls nicht offiziell von der FAI anerkannten Rekordfahrt der "Snow Bird". Sie startete am 4. März 1957 in Weymouth und landete, ohne zwischendurch betankt worden zu sein, nach 264,2 Stunden und 15.205 km auf dem Mariniefliegerstützpunkt Key West/Florida. Dabei wurde zwei Mal der Atlantik überquert.[4] Den inoffziellen Streckenrekord hatte zuvor das deutsche Luftschiff LZ 127 Graf Zeppelin mit 11.233 km mit seiner Fahrt von Friedrichshafen nach Tokio im Jahr 1929 inne.

Weblinks Bearbeiten

Einzelnachweise Bearbeiten

  1. Historic document Seite 70
  2. a b c Flight, Indoor Aerial; Ausgabe: vom 16. August 1957; Seite 214; online als PDF abgerufen am 26. Dezember 2016
  3. World endurance record; Aviation Week and Space Technology; Ausgabe vom 31. Mai 1954 Seite 7; online hinter Anmeldeschranke im Archiv von Aviation.com; abgerufen am 18. Dezember 2016
  4. http://www.blimpinfo.com/history-2/this-mo-in-hist/this-mo-in-hist-mar-2/zpg-2-snowbird-records/ abgerufen am 10. Oktober 2016

Kategorie:Luftschiff

The Goodyear ZPG-2 naval airships were the first patrol airships to be constructed after WWII; the ZPG-2 made its maiden flight on March 20, 1953. Twelve ZPG-2 airships were built by Goodyear. The ZPG-2 (1), a 975,000 cubic foot airship, piloted by CDR M. Henry Eppes in May 1954, demonstrated its endurance in an unrefueled flight of 200.2 hours. The ZPG-2 was modified (W) to accommodate Airborne Early Warning (AEW) electronics. A large radar dome was located on the top of the envelope for a height finding radar and another radar antenna was installed in a dome below the control car. Five ZPG-2W airships were constructed by Goodyear. The ZPG-2W was powered by two 800 hp Wright Cyclone 7 engines; the airship was 343 feet in length with a diameter of 75 feet. The crew consisted of 14 to 17 men and the top speed was 80 mph.

ZPG-2W and ZPG-3W airborne early warning airships flying out of Naval Air Station Lakehurst, New Jersey, were another part of the Navy air defense effort from 1954 to 1962. Assigned to the Inshore Barrier, they provided radar coverage in the area between the DERs on the Contiguous Barrier and the ground-based radars of the Inshore Barrier. The airships were deflated in 1962.


The ZPG-2W was designed for Airborne Early Warning duty. On top of the bag is the height-finder radar in a fiberglass radome about 7 feet high. Everything was supported only by the low pressure of the helium spread over the large area of the bag. The pressure was just high enough to force water up 1.5 inches (3.75 cm) in a tube, yet it supported the radome, the radar antenna, and the radar equipment. Additionally, most of the car weight is also suspended from the top of the bag by cables attached to two "catenary curtains" running parallel and on each side of the top midline. The long dimple near the top of this 2W is due to these catenary curtains.


Willie Victors were supplemented by the ZPG-2W and ZPG-3W blimps of Airship Airborne Early Warning Squadron 1 (ZW 1), flying out of Lakehurst. The airships normally patrolled Station 6 of the Atlantic Inshore Barrier, off the northeast coast of New Jersey, every other day. Like the WV-2s, the airships were equipped with a complete CIC, including radar operators and air intercept controllers.42

The Navy had purchased five nonrigid airships from Goodyear in 1954 for the airborne early warning mission. Originally ZP2N-1Ws, they were redesignated ZPG-2W in 1954 and EZ-1B in 1962. The ZPG-2W was equipped with an APS-20 air search radar inside the gas envelope and an APS-69 height-finding radar mounted on top of it. It carried a crew of twenty-one and had an endurance of over two hundred hours. In 1956, the Navy ordered four ZPG-3W (EZ-1C as of 1962) airships from Goodyear; they began flying barrier patrols from Lakehurst in December 1959. Slightly larger than its predecessor, the 404-foot-long ZPG-3W was the last airship delivered to the Navy.43

The airship patrol was hampered from its inception by limited funding, which restricted flight hours and the availability of aircraft for air intercept controller training. At one point ZW 1 was restricted to a hundred flight hours per month, a paltry amount considering a single airship's endurance. In July 1959, CINCNORAD requested that the Navy move ZW 1 to San Diego to provide better radar coverage for southern California, but the Navy declined, due to the absence of airship facilities in San Diego and lack of funds to construct them. In June 1960 a ZPG-3W crashed when the gas envelope collapsed in flight, and on 31 October 1961 the Navy's last airship units were decommissioned. Two ZPG-3Ws that had been kept at Lakehurst for research were retired when the Navy terminated its airship program on 31 August 1962.44


ZPG-2 / ZPG-2W "N" Series

The ZPG-2 was intended for antisubmarine warfare (ASW) patrols of 2-3 days duration, while the modified ZPG-2W was designed for all-weather airborne warning (AEW) missions. These airships were used for Airborne Early Warning and carried a 40 ft. diameter search radar antenna inside the envelope and had a radome on top of the envelope. Twelve were ordered. The engines were located inside a double-deck car. They first flew in March 1953.

The control car was 83 feet long and 11 and one-half feet wide, and was divided into two levels. The upper deck had comfortable bunks and a wardroom equipped with a modern galley. The lower spaces housed the operational part of the car. This was where all the controls for flying the airship, as well as the equipment necessary to perform the mission assigned, were located.

One of the characteristics of the Navy’s non-rigid airships over the years had been the letter-class identification of “N” for non-rigid. It is fitting that the story of the last airships operated by the Navy were initially given the class designation of "N."

The success of the K-class airships in WW II ASW operations diminished the need for the much improved M-class of the late WWII period, only four of which were built. Following the war, it was clear that the improved versions of the K ships could handle many LTA tasks. However, with the installation of radar, towed sonar and other new ASW systems, in addition to the need for greater patrol ranges, there was a need for ships larger than the M-class. In 1947, the Bureau of Aeronautics initiated a design competition for a larger ASW airship to incorporate the new requirements. Goodyear and Douglas were contenders. The Navy purchased the Douglas design, but subsequent arrangements led to Goodyear building the new Nan ship.

Initial go-ahead in 1948 covered design engineering, mock-up and a ground test propulsion system. Two Wright R-1300-2 air-cooled engines, mounted in the car, drove two reversible-pitch propellers on outriggers, with clutches and transmissions so that either engine could drive both propellers, or use both engines. While this work proceeded, the contract for the ZPN-1 prototype was signed. It would be the largest nonrigid airship built, with an 875,000-cubic-foot envelope, a double-deck car with ample provision for the 14-man crew, extensive ASW equipment and in-flight refueling capability for extended operations refueled by accompanying Navy ships.

In January 1950, the ground test rig was running, but even this lead wasn’t enough when transmission difficulties encountered later in the year delayed the first flight into 1951. Meanwhile, production versions were ordered as the ZP2N-1, which had many improvements, including a larger envelope of 1,011,000 cubic feet. The ground rig resumed running in early 1951, with power plant installation in the N-1 in April, and first flight in June. It was soon realized that the ballonets would have to be replaced because of fabric characteristics, but this was postponed until after the Board of Inspection and Survey (BIS) trials. Late in 1950, flight testing was interrupted for modifications, including increased fin strength and reduced control system friction.

Four fins called "ruddervators" were used to control ZPG-2/. They are unique in that they were positioned at 45 degree angles at the stern of the craft rather than the traditional vertical/horizontal 90 degree positions. The purpose behind the "X" configuration was to provide more ground clearance between the stern of the envelope and the ground during takeoff and landing operations. As with heavier-than-air craft, lighter-than-air craft of the ZPG-2/2W type, which were normally flown "heavy", took off and landed in a raised nose, lowered tail configuration. Because of the craft's length of approximately 350 feet, the "X" configuration was absolutely necessary. Throughout the entire maneuvering envelope this configuration provided superb responses to control inputs. Contrary to previous airship cockpit configurations, which commonly had the aircraft commander in the left seat controlling the elevator and the co-pilot (rudder man) providing rudder control, a yoke control column was provided for each pilot position. Elevator control was the normal "push-pull" on the yoke, while rudder control was through the control wheel. A rather unique feature of this control system is that any single or multiple control input, such as down elevator or down elevator combined with a turn signal, used all four control surfaces at the same time. The degree of travel of the individual surfaces varied according to the amount of single or multiple inputs. To help ease the pilots' workload, a "spring" or "Flettner" tab is installed on each of the control surfaces which automatically moves in the opposite direction of its control surface thus providing additional "boost" to the control system.

Early 1952 saw final solution of the fin design problem, with tail surfaces further modified for final tests at Akron, followed by June delivery to Lakehurst, and Navy Preliminary Evaluation (NPE) in July. The NPE results were disappointing, particulary in the airship’s performance and further tests followed to explore specific improvements.

Meanwhile the first production ZP2N-1 was approaching completion and an AEW version of the N-type, the ZWN-1, was begun. Activity came to a halt at Goodyear during a fall strike, and the first ZP2N-1 did not fly until May 1953. By this time the ZWN-1 had been redesignated ZP2N-1W, a prototype ordered, and first flight scheduled for September 1954. It would feature larger radar antennas inside the envelope than could be mounted externally without excessive drag.

Lakehurst operations with N-1 and flight testing of the ZPPN-1 at Akron continued through spring, summer and into fall. Mock-up inspection of the -1W took place in May. While the flights of N-1 showed the potential of the N, they also confirmed the need for the larger envelope, as in the case of the ZP2Ns. In November, N-1 was deflated for the ballonet replacement, and was subsequently overhauled and rebuilt with a larger 975,000-cubic-foot envelope.

After a delay to correct a transmission problem, the first ZP2N-1 was delivered to Lakehurst late in the year for Navy trials. A ballonet failure, due to overpressurization in January 1954, required corrective action to the pressure system, but the fourth ZP2N-1 was delivered that month. Spring saw the first APS-20B installation in the fifth ship, with BIS trials of the new radar at Lakehurst. The airships were also redesignated at about this time, with the Ns becoming ZPGs. The ZP2N-1 and 1W became ZPG-2 and 2W, respectively. The first fully-equipped ZPG-2 was delivered from Akron to the fleet for operational use in July.

In May 1954 a ZPG-2 airship under Commander Marion Eppes departed NAS Lakehurst for an endurance flight which took her north to Nova Scotia, east to Bermuda and then south to Nassau, the Caribbean Sea and the Gulf of Mexico. The airship landed at NAS Key West on May 25 with.an elapsed time of 200.1 hours or more than 8 days in the air. It was a notable achievement and Cdr. Eppes was awarded the Harmon International Trophy for his achievement. At about this time, the Chief of Naval Operations ordered a series of tests to evaluate the all-weather, continuous-patrol capabilities of the airship. These features were of particular concern during the 1950s because the U.S. was seeking a reliable, high-endurance AEW platform which could detect incoming enemy bombers.

BIS trials of the ZPG-2 were completed in December 1954, and ZX-11 began extended operational trials early in 1955, while another ZPG-2 went to Naval Air Development Unit, South Weymouth, Mass., for all-weather tests with emphasis on extreme winter-weather conditions. The first flight of the ZPG-2W early in the year coincided with increased interest in the use of nonrigid airships as part of the national early warning network.

With these tests completed successfully, the drama involving the final phase of the tests, a long-distance flight, took center ring. The Navy was out to do nothing less than break the long-distance record set by the German rigid airship Graf Zeppelin in 1929, when she flew nonstop from Friedrichshafen, Germany, to Tokyo, Japan, a distance of 6,980 miles, without refueling. There had not been a transatlantic airship flight in 12 years.

The long-distance flights had their origins in the early fifties when the Navy’s LTA advocates were struggling to prove the capabilities and suitability of airship operations in a modern and fast-moving Navy. The success of the airship in WW II had been eclipsed by the new advances in fixed-wing aircraft. Thus, it was thought necessary to demonstrate anew the capabilities of the airship platform to prove it could perform the duties required for ASW and AEW operations. These requirements were accentuated by the growing need for a reliable airborne platform which could operate around the clock in all types of weather.

The crew of the Snow Bird (the name of the ZPG-2 airship used in the long-distance flight) was a specially selected group of volunteers. The pilot in command was Commander Jack R. Hunt, supported by two copilots, Commander Ronald W. Hoel and Lieutenant Commander Robert S. Bowser. Extensive preparations had been made for the flight. Fuel consumption was carefully calculated and graphically plotted. Every item taken aboard was carefully weighed to ensure the ZPG-2 airship would be within the weight limits necessary for correct fuel consumption and lift rate.

On Monday, March 4, 1957, at 1832 (EST) Snow Bird lifted off from Naval Air Station, South Weymouth for her epic-making flight. The record for continuous non-refueled flight was 200 hours and 12 minutes aloft. Snow Bird officially eclipsed this record at 0245 (EST) on March 13, and broke a second record later that day. The distance record established by the German airship Graf Zeppelin in August 1929 fell when Snow Bird passed the 6,980-mile mark in her tricontinental journey. Snow Bird continued her flight, having established two new world records. On March 15, 1957, at 1844, Snow Bird landed at NAS Key West. The voyage took 264.2 hours and covered a distance of 9,448 miles. No airship of any type had ever flown that far or remained aloft that long without refueling. For his contributions as commander and pilot of Snow Bird’s record flight, Cdr. Hunt was awarded the Harmon International Trophy on November 12, 1958. The award was presented to him by President Eisenhower. Three years later, one flew for 264 hours (11 days).


Airships

The Navy’s last airships were sophisticated vehicles and lighter-than-air advocates of the day believed them to be competitive with other airborne vehicles in the Naval Aviation inventory, particularly in the areas of airborne early warning (AEW) and antisubmarine warfare. One of their strong points was the ability to remain in the air for long periods of time. Every opportunity was taken to demonstrate this unique capability and in the process many new records were established.

ZPG-2W and ZPG-3W airborne early warning airships flying out of Naval Air Station Lakehurst, New Jersey, were a part of the Navy air defense effort from 1954 to 1962. Assigned to the Inshore Barrier, they provided radar coverage in the area between the DERs on the Contiguous Barrier and the ground-based radars of the Inshore Barrier. The ZPG-2W and ZPG-3W blimps were assigned to Airship Airborne Early Warning Squadron 1 (ZW 1). The airships normally patrolled Station 6 of the Atlantic Inshore Barrier, off the northeast coast of New Jersey, every other day. The airships were equipped with a complete CIC, including radar operators and air intercept controllers. The airship patrol was hampered from its inception by limited funding, which restricted flight hours and the availability of aircraft for air intercept controller training. At one point ZW 1 was restricted to a hundred flight hours per month, a paltry amount considering a single airship’s endurance.

With the first ZPG-2W delivered to Lakehurst in May 1955, production and operation of the ZPGs continued, interrupted by a suspension cable failure problem that resulted in grounding the ships for replacement with redesigned cable assemblies during the summer. By end of 1955 the first delivery of a ZPG-2W to ZP-3 had been completed.

Beginning January 14, 1957, a continuous patrol was maintained for 10 days, 200 miles off the coast of New Jersey, by personnel from the Naval Air Development Unit, South Weymouth and Airship Airborne Early Warning Squadron 1. The weather proved to be the roughest part of the test. It was the worst the area had experienced in 35 years. The crews and their airships dealt with snow, freezing rain, icing, sleet, fog, rain, zero temperatures and high surface winds. During the patrol, all military and commercial aircraft were grounded due to severe weather, but the airships kept going and continued their patrols without mishap.

On June 28, 1957, ZPs 1 and 4 were disestablished, and ZX-11 was disestablished on December 1 of that same year. Before the ZPG-3W made her first flight in July 1958, production of the 12 ZPG-2s and five ZPG-2Ws purchased had been completed and the -2s had set a number of records for extended-duration flights.

In July 1959, CINCNORAD requested that the Navy move ZW-1 to San Diego to provide better radar coverage for southern California, but the Navy declined, due to the absence of airship facilities in San Diego and lack of funds to construct them.

Four ZPG-3Ws were delivered, but a fatal accident to the first one at sea in the summer of 1960 and a change in early warning mission left the ZPG-2s as the major LTA long-endurance aircraft.

On November 30, 1959, ZP-2, the oldest airship patrol squadron in the Navy, went out of business. ZW-1 was redesignated ZP-1 on January 3, 1961, and continued as an ASW squadron. On June 21, 1961, the Secretary of the Navy announced plans to terminate the Navy’s LTA program. Operations continued into the fall of 1961, when all fleet operations were ended. By the end of October 1961, ZPs 1 and 3 were disestablished. They were the last operating units of the Navy’s LTA branch. Two research and development ZPG-2s continued their special assignments as a flying wind tunnel and an ASW research laboratory through August 1962, and then all Navy LTA operations came to an end.

During the following decade, various individuals and organizations attempted to rekindle the Navy’s interest in LTA. These attempts were generally not successful although some minor studies on LTA were conducted.

The Navy purchased five nonrigid airships from Goodyear in 1954 for the airborne early warning mission. Originally ZP2N-1Ws, they were redesignated ZPG-2W in 1954 and EZ-1B in 1962. The ZPG-2W was equipped with an APS-20 air search radar inside the gas envelope and an APS-69 height-finding radar mounted on top of it. It carried a crew of twenty-one and had an endurance of over two hundred hours.

The airships employed by the Navy after WW II included the operating types used in the war, as well as some modified and several new types/classes. The G and L-types were used briefly in the postwar period. By 1947 all of the L-types had either been sold, stricken or placed in storage. Some of the G-types were still in service with the Naval Airship Training and Experimentation Command in 1947. During WW II the designations that applied to these four airship classes were ZNP-K for the K-types, ZNN-G and ZNN-L for G and L-types and ZNP-M for the M-type.

In April 1947, the Navy’s General Board modified the airship designation system by dropping the “N” which stood for non-rigid. This was done because the board had scrapped the rigid airship program. After the "N" was dropped, the designations became ZPK, ZTG, ZTL (T was used for training vice N) and ZPM. These changes were published in.

WWII 1947 1953 1954 1962 G ZNN-G ZTG K ZNP-K ZPK ZP2K ZSG-2 ZP3K ZSG-3 ZP4K ZSG-4 ZP5K ZS2G L ZNN-L ZTL M ZNP-M ZPM N ZPN ZPG-1 ZP2N-1 ZPG-2 SZ-1B ZWN-1 ZP2N-1W ZPG-2W EZ-1B ZWG-1 ZPG-3W EZ-1C

On 19 April 1954, model designations for airships were modified to conform with designations for heavier-than-air aircraft. Similar to the system the Navy used for its other aircraft, the difference was the inclusion of the builder’s initial in the airship’s designation. Basically, the envelope designation letters "K" and "N" were replaced by manufacturer's letters, standard suffix numbers and letters were uniformly applied and the patrol class of airships was divided into patrol and antisubmarine classes. The changes were as follows: ZP2K became ZSG-2; ZP3K became ZSG-3; ZP4K-ZSG-4; ZP5K-ZS2G; ZPN became the ZPG-1; ZP2N-1 - ZPG-2; and ZP2N-1W - ZPG-2W.