Goodyear ‘K’ Class / ZP / ZPK Class / ZSG / ZS2G
The L-1 was followed by the prototype of a new class of naval airship which was destined to be built in larger numbers than any other single airship type, either rigid or non-rigid; the K-Class. K-1 was a one-off experimental ship built by the Naval Aircraft Factory in 1931, using a Goodyear envelope of 319,900 cu.ft., and was remarkable mainly in being the first U.S. Navy blimp to have the car attached flush to the underside of the envelope. At that time the Navy was primarily interested in the new rigid airships then being built, but with the disbandment of the Army L.T.A. Section the Navy became responsible for coastal patrol work as, well as long-range scouting. As a result there began, with the aid of Goodyear, the serious development of the patrol-type airship, and K-2 was the result. Powered by two 550 h.p. Pratt & Whitney Wasp engines, she was the largest non-rigid of her day, with an envelope of 404,000 cu.ft. capacity. First flight took place on December 8, 1938, and she was soon to be followed by many more of her kind.
ZP-14 squadron was formed in 1944 to operate from Port Lyautey, French Morocco, the airships being flown across the Atlantic via the Azores, the first non-rigids ever to make the crossing. First across were K-123 and K-130, both ships completing the 3,145 mile journey between May 29, and June 1, 1944, in a flying time of 58 hours. In the following months, K-ships were based in southern France (Cuers), Sardinia, Italy (Pisa and Venice), and at a temporary mooring mast at Gibraltar. Primary mission in the area was anti-submarine work in the Straits of Gibraltar, but they also completed many hours of mine sweeping operations in conjunction with surface vessels of the Royal Navy. Using magnetic airborne detection gear, flying mainly at night or in bad weather when other types of aircraft could not be used due to the low flight altitudes required on this work, they were able to maintain round-the-clock patrols. After the arrival of the airships in the area no, more U-boats were able to enter or leave the Med. without detection and eventual destruction.
Larger numbers were built of K-Class airships than of any other single type.
After 1948, the K-Class became known as the ZPK- Class and many of these were modified with larger envelopes and improved electronic detection gear to become ZP2K (456,000 cu.ft.), and ZP3K (527,000 cu.ft.). These were followed in 1954 by the new ZP4K and ZP5K which later became designated the ZSG-4 and ZS2G-1 respectively.
The "K” class are the standard U.S. Navy patrol airships and 130 were built during war. Most were modified by 1955 into ZP2K and ZP3K, with the latest radar search equipment and increased capacity envelope.
Goodyear ZP2K
Goodyear ZP3K
The ZSG-4 was a new development of K-Class. 15 built 1953--1955, and in service to 1961.
There were 18 ZS2G-1 built 1954-56 and they remained in service to 1961.
While the ZSG-4 was essentially a modified K-Class, the ZS2G-4 was an entirely new design with an envelope of 650,000 cu.ft. and a unique inverted Y tail configuration. Carrying a crew of eight and equipped with the latest in anti-submarine devices, these ships could be refuelled from surface craft at sea and re-ballasted by a water pick-up system. The prototype flew on July 22, 1954, and the type remained in service until 1961.
Immediately after the war, Goodyear bought back from the Navy four complete L-ships and one K-ship to form the basis of a new commercial fleet. Goodyear were not the only company to be interested in the airship, however.
The Douglas Leigh advertising company purchased no less than 29 surplus L and K‑ships in February, 1946. In September 1946, the actress Elizabeth Taylor christened the first Leigh airship at ceremonies in the Lakehutst hanger. The next day, the “MGM Aiship” inaugurated aerial operations. A second ship promoting the Ford Motor Company was launched, and a third, the “Tydol Airship” (ex-K-76), was pressed into service early in 1947.
East Coast operations were promising , so similar enterprise was organised in California, with headquarters at Moffat Field. Flights using an L-ship for promotion commenced in spring 1947.
The coming of television advertising and the high cost of replacing the war surplus ships soon began to tell, and by the early 1950s Goodyear were alone as commercial airship operators in America.
The later K-ships of 425,000 cu. ft. with a crew of three officers and nine men, had a range of 2,000 miles at 45 m.p.h. with a normal fuel load, and a top speed of 75 m.p.h. Total orders for the K-Class amounted to 138 (K-2 to K-139), but the last four were cancelled before completion. Total production was 134 ships, K-2 to K-135. Post-war many modified as ZP2-K and ZP3-K.
ZS2G-1
Thirteen naval airships were deflated and placed in long-term storage in case of future need, while two ZPG‑2s were retained for experimental work with the Airship Test and Development Department at Lakehurst. In addition, one ZS2GA was made available to Mississippi State University for a programme of boundary layer control research on airship envelopes. When these ships, too, were deflated at the end of 1962, forty‑five years of U.S. Naval airship operations came to an end.
The ZP3M long endurance patrol airship, with a volume of 725,000 cu. ft. and length of 310 ft. One ZP3M has remained airborne for more than a week. Early ZPM-1 aircraft have two 550 h.p. Wasps; later ZP3Ms have two 700 h.p. Wright Cyclones. The ZP2M is a modernised ZPM-1, with revised electronics.
Goodyear ZP3M
Goodyear ZPG2 / ZP-3
Variant: Piasecki Heli-Stat
GZ-6
Volume: 404,000 cu ft to 425,000 cu ft.
Length: 251.7ft.
Max Dia: 62.5ft.
Engines: 2 x 420 h.p. Wright R-975-28 Whirlwind 9 or Pratt & Whitney R-1340-AN-2 Wasp.
ZSG-2 & ZSG-3 (GZ-10)
Volume: 456,000 cu ft and 527,000 cu ft.
Length: 267ft.
Max Dia: 70ft.
Engines: 2 x 550 h.p. Pratt & Whitney R-1340 Wasp.
ZSG-4 (GZ-12)
Volume: 527,000 cu ft.
Length: 267ft.
Max Dia: 70ft.
Engines: 2 x 550 h.p. Pratt & Whitney R-1340 Wasp.
ZS2G-1 (GZ-15)
Volume: 650,000 cu ft.
Length: 285ft.
Max Dia: 68ft.
Engines: 2 x 800 h.p. Wright R-1300-4 Cyclone 7.
ZP2K
Volume: 456,000 cu. ft.
ZP3K
Engines: 2 x 550 h.p. Pratt & Whitney Wasp
Volume: 527,000 cu. ft.
Length: 253 ft
Speed: over 75 m.p.h.
ZP3M
Engines: 2 x 700 h.p. Wright Cyclones
Volume: 725,000 cu. ft.
Length: 310 ft
ZPM-1
Engines: 2 x 550 h.p. Wasps.
