Zeppelin NT
|
|
Zeppelin NT ("Neuer Technologie", German for new technology) is an airship type that has been manufactured since the 1990s by the German company Zeppelin Luftschifftechnik GmbH (ZLG) in Friedrichshafen.
This company can be considered the successor of the companies founded by Ferdinand von Zeppelin which constructed and operated the very successful Zeppelin airships in the first third of the 20th century. There are, however, a number of notable differences between the Zeppelin NT and the dirigibles of those days, as well as between the Zeppelin NT and usual non-rigid airships known as blimps.
| Contents |
Technology
The Zeppelin NT airships constructed so far are 75 m long, with a volume of 8225 m³. They are thus considerably smaller than the old Zeppelins. Furthermore, they are inflated exclusively with the non-flammable noble gas helium.
In standard operations with a maximum payload, the gas cells do not create enough buoyancy to make the whole ship "lighter-than-air." The negative buoyancy is overcome with engine power. The design is therefore considered a hybrid airship. The buoyancy can change when traveling with reduced payload and partially emptied fuel tanks, but usually the Zeppelin NT flies with a net downward force of about 300 kg (660 pounds).
The Zeppelin NT is a semi-rigid airship. It is unlike both the original Zeppelins that had a rigid skeleton and non-rigid blimps. It has an internal triangular truss (support structure) made of graphite-reinforced plastic and three longitudinal girders made of aluminium. This frame holds the engines, control car and the steering fins. Additionally, this structure is tightened with aramid cords. It masses only about 1000 kg (2200 pounds).
Hull
Inside the hull of the historical Zeppelins the gas cells were separate entities. However the hull of the Zeppelin NT serves both as the hull and as the gas cell. It is made of a three-layered laminate: one gas-tight layer of Tedlar (PVF), one polyester fabric layer to provide stability and one polyurethane layer suitable for thermic welding that serves to connect the separate laminate panels.
To preserve its outer form, a slight overpressure of about 5 millibar is maintained within the hull. As in blimps, this pressure is kept constant by using ballonets. The ballonets have a total volume of 2,000 m³.
Propulsion and steering
Three propeller engines of the type Textron Lycoming IO-360 with a power of 147 kW (197 hp) each provide the Zeppelin NT with excellent maneuverability. Two lateral engines, equipped with tearing propellers and usually aligned horizontally, can be turned 90° upward or 30° downward. The aft engine powers a pushing propeller that can be turned 90° downward, as well as a steering propeller directed to the side and working similarly to the lateral-thrust units of some ships.
Instead of four rudder and elevator fins, the Zeppelin NT uses only three, which saves weight. As a side effect, the loss of one fin can be compensated with the remaining two.
The controls are implemented by fly-by-wire technology, with the pilot using a joystick to steer in three dimensions.
Flying capabilities
The design currently has a range of some 900 km and reaches top speeds of 125 km/h. The standard cruising speed of 70 km/h for tourist flights can be attained using the rear propeller only. Standard operational altitude is 300 m, but up to 2,600 m is possible. Their maximum permitted takeoff weight is 10,690 kg, with a payload of 1900 kg.
The Zeppelin NT is able to start and land vertically. Only three helpers are required on the ground.
Range of application
Since August 15 2001 the Deutsche Zeppelin-Reederei (German for German Zeppelin shipping company) has successfully offered joyrides with Zeppelin NT airships. The hull surfaces are marketed as advertising space. The DZR was founded as a subsidiary of the ZLG in January 2001.
The craft are also used as observation platforms for photographers and television commentators covering major events.
Due to their capability for long low-vibration flight (up to 24 hours), the ZLG also considers the airships well-suited to research missions for environmental observations, troposphere research or prospecting natural resources.
Project history
The modern development and construction was financed from an endowment, initially funded with money left over from the earlier Zeppelin company, that had been under the trusteeship of the Mayor of Friedrichshafen. A stipulation on the endowment limited use of its funds to the field of airships. Over the many years, the investment value of the endowment grew to a point where the time seemed right to use it for the design, development, and construction of a new Zeppelin.
The initial design study was prepared in 1989. The ZLG was founded as a spin-off of the Zeppelin company in September 1993. It began to construct a prototype in 1995. The prototype first took to the air in September 1997.
On July 2 2000, the centennial of the first Zeppelin flight, the prototype SN 01 was christened D-LZFN Friedrichshafen. Subsequently, it traveled some 3600 km in test flights.
In 2001 the company began manufacturing the Zeppelin NT in series and began to exploit the airships commercially. The second ship SN 02 was christened D-LZZR Bodensee on August 10 2001 and started to give joyrides five days later. By the end of that year, it had already transported 3222 passengers, a figure that rose to about 30,000 by November 2003.
During the Oktoberfest of 2002 a Zeppelin NT was used for radio experiments in connection with the European Galileo positioning system project for the German Aerospace Center and the ESA.
The third Zeppelin NT SN 03 was designated D-LZZF and first flew in February 2003.
The Friedrichshafen is intended to be used for training pilots, for special flights and for presentations. All further ships will be used commercially or sold. As a tribute to the days of Zeppelin mail, a number of mail-carrying flights are planned.
On March 2 2004 the ZLG sold a Zeppelin NT for the first time. SN 02 was acquired by the Japanese Nippon Airship Corporation and will be transferred in June 2004, following the historical route of the 1929 world tour of the famous dirigible LZ127 "Graf Zeppelin". The company intends to use the airship mainly for joyrides and advertising.
Steve Fossett and Paul Stroehle set the current speed record for aircraft over one kilometer on Wednesday, October 27 2004 in Friedrichshafen, Germany with a Zeppelin NT.
External links
- Zeppelin Luftschifftechnik GmbH (http://www.zeppelin-nt.de/index_e.htm) -- manufacturers' homepage
- Deutsche Zeppelin Reederei (http://www.zeppelinflug.de/pages/E/haupt.htm) -- booking joyrides with Zeppelin NT airshipsde:Zeppelin NT