ufol9503.03
Date: Fri, 3 Mar 1995 22:48:06 -0500
From: William Uhouse
Subject: 1897 airships ? Not yet.

Me again.

It seems they may have been on the drawing board but not in the air. However
balloons (Nonrigid frame aircraft were floating around since 1850 or so.)
Comptons reference below is interesting reading in relation to the airship
article. I think the point made about describing things in "known terms "
should be given alot more consideration, I think I am repeating myself here
so I will just shut my face and go to bed for the night.

WBU

Comptons; (Edited)

airship

An airship is a type of lighter-than-air AIRCRAFT with propulsion
and steering systems; it is used to carry passengers and cargo.
It obtains its buoyancy--as does a BALLOON--from the presence of
a lighter-than-air gas such as hydrogen or helium (see
ARCHIMEDES' PRINCIPLE). The first airship was developed by the
French; called a balloon dirigible ("steerable balloon"), it
could be steered and could also be flown against the wind.

TYPES OF AIRSHIP

Two basic types of airship have been developed: the rigid
airship, the shape of which is fixed by its internal structure;
and the nonrigid "blimp," which depends on the pressure created
by a series of air diaphragms inside its gas space to maintain
the shape of its fabric hull. Inventors sought to combine the
best features of these models in a semirigid type, but it met
with only limited success. Today only the nonrigid airship is
used.

Rigid Airship

The rigid airship's structure resembled a cage that enclosed a
series of balloons called gas cells. These cells were tailored
to fit the cylindrical space and were secured in place by a
netting that transmitted the lifting force of their gas to the
structure. Each gas cell had two or more valves, which operated
automatically to relieve pressure when the gas expanded with
altitude; the valves could also be operated manually so that the
pilot could release gas whenever desired.

Also on board was a ballast system that used water as ballast. On
the ground this ballast served to make the airship heavier than
air. When part of it was released, the airship ascended to a
cruising altitude where the engines supplied propulsion, and
further ballast could be released to gain more altitude. As fuel
was consumed, the airship became lighter and tended to climb.
This was countered in hydrogen-inflated airships by simply
releasing gas into the atmosphere.

The method was uneconomical, however, with helium-inflated
airships, and they were therefore equipped with ballast
generators, apparatuses that condensed moisture out of the
engines' exhaust gases to compensate for fuel that was consumed.
But this ballast-generating equipment was expensive, complex,
heavy, and difficult to maintain and was thus one of the most
serious disadvantages of airships filled with the safer but more
expensive helium.

Nonrigid Airship

In contrast to the rigid airship, the nonrigid blimp has no
internal structure to maintain the shape of its hull envelope,
which is made of two or three plies of cotton, nylon, or dacron
impregnated with rubber for gas tightness. Inside the gas space
of the hull are two or more air diaphragms called ballonets that
are kept pieces by a thunderstorm over southern Ohio on Sept. 3, 1925.
The ZR-2 (British R-38) was procured in England but crashed on
Aug. 24, 1921, before it could be delivered to the United
States. The ZR-3 Los Angeles, built in Germany by Luftschiffbau
Zeppelin, made its transatlantic delivery flight during Oct.
11-15, 1924; it was flown successfully until decommissioned in
1931 and was scrapped in early 1940. The ZRS4 and ZRS5 AKRON AND
MACON were built by the Goodyear-Zeppelin Co. of Akron, Ohio.
These 184,000-cu m (6,500,000-cu ft) sister ships were 239 m (785
ft) long and 40 m (133 ft) at maximum diameter, and were powered
by eight 560-hp Maybach engines. Their design was unique in that
it provided for an internal space for five airplanes that could
be launched and retrieved while the airships were in flight. The
Akron first flew on Sept. 23, 1931 and was lost in a storm over
the Atlantic on Apr. 4, 1933; the Macon first flew on Apr. 21,
1933, and crashed in the Pacific on Feb. 12, 1935.

HISTORY OF NONRIGID AIRSHIPS

The first successful nonrigid airships were built by the French.
In 1852 Henri Giffard built an airship of 3,200 cu m (113,000 cu
ft) powered by a steam engine. The brothers Albert and Gaston
Tissandier constructed a 1,062-cu m (37,500-cu ft) airship
propelled by a battery-powered electric motor in 1883, and the
following year Charles Renard and Arthur C. Krebs built the
1,869-cu m (66,000-cu ft) La France, which also used electric
power. At the turn of the century the Brazilian aeronaut Alberto
SANTOS-DUMONT built and flew a series of small airships in
France, all of which used gasoline engines. Blimps were
effectively used by the British and French in World War I in
maritime reconnaissance against German submarines. The term
blimp, a British slang expression of unknown origin, came into
use about this time.

In World War II, the United States was the only power to use
airships. The navy used them for minesweeping and antisubmarine
patrols. Its more than 150 blimps were operated from bases on
the east and west coasts, the Gulf of Mexico, the Caribbean, and
as far south as Brazil. The workhorse of these forces was the
K-type blimp, 76 m (253 ft) long, 18 m (60 ft) in diameter,
containing 12,900 cu m (456,000 cu ft) of gas, and powered by two
425-hp engines that gave a top speed of 80 km/h (50 mph). Blimps
are not fast, but whereas an airplane can remain airborne for
only a few hours, a K-ship could stay aloft for 60 hours. In
1944, six K-ships flew across the Atlantic to Morocco, where they
established a low-altitude antisubmarine barrier across the
Strait of Gibraltar; later they operated from bases at Cuers,
France, and Pisa, Italy.

After 1945 the navy continued to use blimps in antisubmarine
warfare, and some were equipped with extraordinarily large
airborne radar sets for early offshore warning of bomber attacks
against the United States. The largest of these airships was the
ZPG-3W; it displaced 43,000 cu m (1,516,000 cu ft) and was 121 m
(403 ft) long and 22.5 m (75 ft) at maximum diameter--the largest
blimp type ever built. On Aug. 31, 1962, the navy terminated its
use of blimps.

The Goodyear Blimps

The most long-lasting use of airships has been by the Goodyear
Tire and Rubber Company. The Pony was built in 1919 and the
Pilgrim in 1923. After 1928 the fleet was expanded with the
Puritan, Volunteer, Mayflower, Vigilant, Defender, Reliance,
Resolute, Enterprise, Ranger, and Columbia. During the 1930s
these airships were used for advertising, and !