Information about "Keel-Airships"

semi-rigid airships

Semi-rigid airships are airships, which are a hybrid between a rigid airship and a blimp. Because of the keel construction below the envelope they are also known as keel-airships. There are many parallels to the basic design of non-rigid airships, but some advantages of rigid airships are also used in this hybrid construction.

The main characteristics of these airship types are:

  • The envelope, which contains the lifting gas, has also ballonets inside. (Like a blimp)
  • A rigid structure, build as a keel, runs mostly below the envelope as a gangway (so you can walk over the mostly or completely length of the airship) and is also used as a depot for freight, ballast and fuel / oil.
  • The gondola for crew and the passengers is attached to the rigid structure, also the engines, which can be build into extern  engine gondolas
  • The control elements (the fins with rudders and elevators) are also fixed to the rigid keel, if possible.

Because of the possibility of a more specific attachment, for example of the engines, there can achieved a more effective poweroutput. The gondola is nearly vibration-free and the whole style of the airship is much more rugged.

Examples for semi-rigid airships are:

The military-airships type "Groß-Basenach"
The military-airship "M II" (1909-1912)

The expedition-airships "Norge" and "Italia"
The italian airship "Norge" ("Norway")  masted in Oslo (1926)
The italian airships "Norge" and "Italia", build by General Umberto Nobile, were used for expeditions to the North Pole. The airship "Norge", build in 1923/24, started its arctic expedition on  May 11th, 1926. They crossed the Pole - aboard was also the very famous polar explorer R. Amundsen. The airship "Italia" started its flight on  May 24th, 1928, but this trip went wrong. In a dramatic rescue operation some of the crewmembers have been saved.
        Characteristics of the airship N1 "Norge"
348 ft   (106 m)
max. Diameter
64 ft   (19,5 m)
671,000 ft³   (19.000 m³)
Engines /
3 Maybach-engines /
245 HP each
max. Speed
60 knots   (113 km/h)

The adevertising airship of the Raab-Katzenstein aircraft-factory
& the Parseval-Naatz-Airships
The assembling of the "Trumpf"- Airship R.K.27 of the Raab-Katzenstein-
factory at Kassel. Really nice to see is the gas filled envelope and
the keel with the gondola and the engines. (1929)
The airship R.K. 27 ,and also the airships D-PN 28, D-PN 29 & D-PN 30 are direct (but semi-rigid) followers of the Parseval-Airships, which have been designed by Dipl.-Ing. Naatz.
The "Odol"-Airship D-PN 30 of the type "Parseval-Naatz" in flight. (1932)