After traveling to The
Mission in San Francisco, California, I was reminded of the mission
itself. To engage the governor is to
comprehend the most recent announcement, and to engage proposal.
The funds have indeed
been brought to the knowledge of the public at-large; this product management
has had many involved and few with relief to the current problems that plague
the State of California in the United States of America.
Most recently my composition
returned a letter to the President of the United States of America making this
the opportunity to return more than a seat.
This aspect to honesty is simply the reservation to what is the balance
of paper to envelope versus the etrade.
Economy is a keel to this boat and the wheel is timing as the belt is
not smitten. To engage thought to
prowess and to acknowledge the work done in Fresno, California, and to
understand that plans change and schedules are written it is the signature
piece that replies.
This product management
of the State of California brings tourism to the tourist and employs the native
to the beauty of stops that would never have brought economy to its feet. To applaud such prowess is held at only the
comprehension as the hands must understand the Fresno, California reserve but
may move the map to chart a more reasonable schedule to the return of money to
the bottom line of the State of California, U.S.A.
My aspect leans toward my
town, San Francisco, California: Chinatown!
To bring The Fillmore to repair and to employ the genius of The Mission
to what is a Japantown example of my city is able to complete with City Works:
I.E.: Cal Trans.
For such, the houses from
The Fillmore make the return the match as the adobe is of great interest to me
and I would enjoy the process to more that the paintings on the murals in The
Mission. To enjoy this hinge as in Stone
Henge it is The Mission with district meetings that would plan the sidewalk to
the amazing architecture that has employed the interest worldwide using
Chinatown as a template. This plan is to
invoke the money to the people and not to the banks. With this plan the product is not the people
it is the tourism driven by the amazement of not Las Vegas in its employment of
the Mall of America, it is the driven amazement of personal investment while
those of us that are either native or born and raised here enjoy the beauty of
growth and the invitation of international travel to visit these most amazing
places; being present (to be explained) as this is only a synopsis in short.
For the fact: Mission to
the Fillmore, Fillmore to the Tenderloin (The Ferry Building) and travel to the
Rigid Airship to engage the small towns in our State of California and to relieve the
overburdened roads in Yosemite and to bring fruition to smaller towns that are of the Interstates, Freeways and Highways. With this plan and the working of the kinks we may produce a plan for the bureau of federal control of air travel and perhaps bring Nevada to a new industry saying that your State is rarely appreciated and not positioning anything other than a landing platform. This would be only a start, to increase would involve the reports of what is needed to improve this proposal and this would all be without the Light Rail or the trail of such improvements that the very trace would change the incredible and also repeat the railroad (modem) that had been torn out in the first part of the last century, date adjusted.
This is a rough draft.
Rigid airship
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For broader coverage of this topic, see
Airship.
A rigid airship is a type of airship (or dirigible) in which the envelope is supported by an internal framework rather than by being kept in shape by the pressure of the lifting gas within the envelope, as in blimps (also called pressure airships) and semi-rigid airships.[1][2] Rigid airships are often commonly called Zeppelins, though this technically refers only to airships built by the Luftschiffbau Zeppelin company.
In 1900, Count Ferdinand von Zeppelin successfully performed the maiden flight of his first airship; further models quickly followed. Prior to the First World War, Germany was a world leader in the field, largely attributable to the work of von Zeppelin and his Luftschiffbau Zeppelin company. During the conflict, rigid airships were tasked with various military duties, which included their participation in Germany's strategic bombing campaign.
Numerous rigid airships were produced and employed with relative
commercial success between the 1900s and the late 1930s. The heyday of
the rigid airship was abruptly ended by the destruction of the Hindenburg by fire
on 6 May 1937. The disaster not only destroyed the biggest zeppelin in
the world but caused considerable reputation damage to rigid airships in
general. Amid widespread public safety concerns, several nations opted
to permanently ground their existing rigid airships and scrap them in
subsequent years.
Construction and operation
Rigid airships consist of a structural framework usually covered in doped fabric containing a number of gasbags or cells containing a lifting gas. In the majority of airships constructed before the Second World War, highly flammable hydrogen was used for this purpose, resulting in many airships such as the British R101 and the German Hindenburg being lost in catastrophic fires. The inert gas helium was used by American airships in the 1920s and 1930s; it is also used in all modern airships.[citation needed]
Although airships rely on the difference in density between the
lifting gas and the surrounding air to stay aloft they can also generate
a certain amount of aerodynamic lift by using their elevators
to fly in a nose-up attitude. Similarly, by flying nose-down down-force
can be generated: this may be done to prevent the airship rising above
its pressure height. Typically airships start a flight with their
gasbags inflated to about 95% capacity: as the airship gains height the
lifting gas expands as the surrounding atmospheric pressure reduces. The
height at which the internal pressure of the gasbags equals external
atmospheric pressure is called the pressure height: if the airship
climbs beyond this it is necessary to vent gas in order to prevent the
gasbags' rupturing.
History
Early history
By
1874, several people had conceived of a rigid dirigible (in contrast to
non-rigid powered airships which had been flying since 1852). The
Frenchman Joseph Spiess had patented a rigid airship design in 1873 but failed to get funding.[3] Another such individual was the German Count Ferdinand von Zeppelin,
who had outlined his thoughts of a rigid airship in diary entries from
25 March 1874 through to 1890 when he resigned from the military.[4] David Schwarz
had thought about building an airship in the 1880s and had probably
started design work in 1891: by 1892, he had started construction.[5]
However, Schwarz's all-aluminium airship would not perform any
test flights until after his death in 1897. Schwarz had secured help in
its construction from the industrialist Carl Berg
and the Prussian Airship Battalion; there was an exclusive contract in
place between Schwarz and Berg, thus Count Zeppelin was obliged to reach
a legal agreement with Schwarz's heirs to obtain aluminium from Carl
Berg, although the two men's designs were different and independent from
each other: the Schwarz design lacked the separate internal gasbags
that characterise rigid airships.[6] Using Berg's aluminium, von Zeppelin was able to start building his first airship, the LZ 1, in 1899.[7]
First practical rigid airships
LZ 1, the first successful rigid airship
During July 1900, Ferdinand von Zeppelin completed LZ 1.[7] Constructed in a floating shed on Lake Constance, it was 128.02 m (420 ft) long, 11.73 m (38 ft 6 in) in diameter with a volume of 11,298 m3 (399,000 ft 3) and was powered by a pair of 11 kW (14 hp) Daimler
engines. The first flight, lasting 20 minutes, was made on 2 July, but
ended with the airship being damaged. After repairs and modifications,
two further flights were conducted in October 1900.[8] However, these initial experiments failed to attract any investors, and Count Zeppelin did not complete his next design, LZ 2,
until 1906. This performed only a single flight on 17 January 1906,
during which both engines failed and the zeppelin was compelled to
conduct a forced landing in the Allgäu mountains; it was subsequently
damaged beyond repair by a storm.[9] Undeterred, another zeppelin with a largely similar design, the LZ 3, was quickly completed and put into flight.[10]
LZ 3 proved to have performed sufficiently to interest the German Army, who opted to purchase and operate it as the Z I until 1913.[10]
Even so, the German Army observed that they required an airship that
would be capable of flying for 24 hours. As this was beyond the
capability of LZ 3, it was decided to design and construct a larger
craft, LZ 4.
This was 136 m (446 ft) long, 12.95 m (42 ft 6 in) in diameter and
powered by two Daimler engines delivering a total of 156 kW (210 hp).[11]
LZ 4 first flew on 20 June 1908, and on 1 July made a spectacular 12
hour cross-country flight during which it was flown over Switzerland to
Zürich and then back to Lake Constance. The 24-hour trial was started
on 4 August, but was interrupted by the failure of one of the engines.
It was moored near Echterdingen
in order to make repairs but a storm arose, causing it to break away
from its moorings, after which it was blown into some trees and caught
fire.[12] The disaster took place in front of an estimated 40 to 50 thousand spectators,[13]
and produced an extraordinary wave of nationalistic support for von
Zeppelin's work. Unsolicited donations from the public poured in: enough
had been received within 24 hours to rebuild the airship, and the
eventual total was over 6 million marks were donated, finally giving
Count Zeppelin a sound financial base for his experiments.[14]
Seven zeppelins were operated by DELAG, the first airline in the world.[15]
DELAG was founded at the suggestion of Alfred Colsman, the business
manager of Zeppelin Luftschiffbau, seeking to capitalise on the German
public's enthusiastic interest in the zeppelin by permitting them
onboard passenger-carrying airships as a commercial venture; von
Zeppelin distanced himself from this commercialisation, reportedly
regarding such efforts to have been a vulgar tradesman's enterprise.[16]
Commencing such flights in 1910, DELAG was initially limited to
offering pleasure cruises in the vicinity of the existing zeppelin
bases.[17]
DELAG soon received more capable zeppelins, such as the LZ 10 Schwaben,
which would carry a total of 1,553 paying passengers during its career,
which involved not only pleasure flights but a number of long-distance
flights to destinations such as Frankfurt, Düsseldorf, and Berlin.[18] The company's airships were also used by the Imperial German Navy for crew training, with the Navy crews operating passenger flights.[19]
By July 1914, one month prior to the start of the First World War,
DELAG's Zeppelins had transported a total of 34,028 passengers on 1,588
commercial flights; over these trips, the fleet had accumulated 172,535
kilometres across 3,176 hours of flight.[20][21] Commercial operations came to an abrupt end in Germany due to the outbreak of the First World War, after which DELAG's airships were taken over by the German Army for wartime service.
During 1911, the first rigid airship produced by the German Schütte-Lanz company was flown. Designed by the naval architect
Johann Schütte, the Schütte-Lanz introduced a number of technical
innovations. The shape of the hull was more streamlined than the early
Zeppelin craft, the hulls of which were cylindrical for most of their
length, simplifying construction at the expense of aerodynamic
efficiency. Other Schütte-Lanz innovations included the use of an axial
cable running the length of the airship to reduce additional stressing
caused by the partial deflation of a single gasbag, the introduction of
venting tubes to carry any hydrogen vented to the top of the ship and
simplified cruciform tail surfaces.
The extended Spiess airship in 1913
The British Royal Navy took an early interest in rigid airships and ordered His Majesty's Airship No. 1 in 1909 from Vickers Limited at Barrow-in-Furness. It was 512 ft (156.06 m) long with two Wolseley engines. It was completed in 1911 but broke in two before its first flight and was scrapped.[22] This caused a temporary halt to British airship development, but in 1913 an order was placed for HMA No. 9r. Due to various factors, including difficulties in acquiring the necessary materials, it was not completed until April 1917.[23][24]
France's only rigid airship was designed by Alsatian engineer Joseph Spiess and constructed by Société Zodiac at the Aérodrome de Saint-Cyr-l'École.[25] It had a framework of hollow wooden spars braced with wire, and was given the name Zodiac XII but had the name SPIESS painted along the side of the envelope.[26] It was 113 m (370 ft 9 in) long, with a diameter of 13.5 m (44 ft 3 in) and was powered by a single Chenu
200 hp engine that drove two propellers. It first flew on 13 April
1913, but it became clear that it was underpowered and required more
lift, so it was lengthened to 140 m (459 ft 4 in) to accommodate three
more gas cells and a second engine was added. Spiess then presented the
airship to the French government as a gift.[27]
After further trials it was not accepted by the French military,
because their view was that smaller non-rigid types would be more
effective.[28] The Spiess airship seems to have been broken-up in 1914.
First World War
During the First World War, the Zeppelin company constructed a total
of 95 military airships. These were operated by both the German Navy and
the Army. German military airship stations had been established before
the conflict and on September 2–3, 1914, the Zeppelin LZ 17 dropped
three 200 lb bombs on Antwerp
in Belgium. In 1915, a bombing campaign against England using airships
was initiated, the first raid taking place on 19 January 1915 when two
airships dropped bombs on Norfolk.
On 31 May 1915 the first bombs fell on London. Raids continued
throughout 1915 and continued into 1916. On the night of September 2–3,
1916 the first German airship was shot down over English soil by Lt. Leefe Robinson flying a BE 2c.
This and subsequent successes by England’s defences led to the
development of new Zeppelin designs capable of operating at greater
altitudes, but even when these came into service the Germans only
carried out a small number of airship raids on Britain during the rest
of the war, carrying on the campaign using aeroplanes and reserving
their airships for their primary duty of naval patrols over the North
Sea and the Baltic. The last casualties occurred on 12 April 1918.[29]
The first British airship to be completed during the war was No. 9r, which was first flown at the end of 1916 and was used for experimental and training purposes.[23] By then, the war against U-Boats was at its height and 9r was quickly followed by four airships of the 23 Class, two R23X Class and two R31 Class,[30] the last being based on the Schütte-Lanz principle of wooden construction, and remain the largest mobile wooden structures ever built.[31] The only significant combat success of these airships, aside from their deterrent effect, was assistance in the destruction of SM UB-115 by R29 in September 1918.[32]
1919–1939
The British R34 in
Long Island during the first ever return crossing of the Atlantic in July 1919
By the end of the conflict, two British airships of the R33 Class
were nearing completion. R33 became a civilian airship, finishing her
career doing experimental work. The R34 became the first aircraft to
complete a return Atlantic crossing in July 1919 but was severely damaged in January 1921 and was subsequently scrapped.[33] R.35, a unique admiralty design, was almost finished when work was stopped in early 1919.[34] R36
and R.37 were stretched R.35s. R.36 was completed after the war as a
civilian airship registered as G-FAAF. R.36 had two engines from the
German L71. Modifications for passenger service involved installing a
131 foot long combined control and passenger gondola to accommodate 50
passengers.[35]
R.36 suffered a structural failure of one horizontal and one vertical
fin. It was repaired and served to aid the police in traffic control for
the Ascot race in 1921. R.36 was damaged in a mooring accident in 1921,
and while repaired R.36 never flew again. Retained for possible use as a
commercial airship R.36 was broken up in 1926.[36]
Four airships of the R38 Class were started but only one completed: it was sold to the US Navy and renamed ZR-2. In June 1921 it broke up in the air over Kingston-upon-Hull
before it could be delivered, killing 44 of its Anglo-American crew.
The last airship that had been ordered amid the First World War was the R80; it was completed in 1920 but was tested to destruction in the following year after it was found to have no commercial use.[37]
After the end of the First World War I, Luftschiffbau Zeppelin resumed building and operating civilian airships. Under the terms of the Treaty of Versailles, Germany were prohibited from building airships with a capacity in excess of 28,000 m3 (1,000,000 cu ft), greatly limiting the company's scope.[38] However, a pair of small passenger airships, LZ 120 Bodensee and a sister ship LZ 121 Nordstern
were built, intended for use between Berlin and Freidrichshafen. They
were subsequently confiscated and handed over to Italy and France as war reparations
in place of wartime zeppelins which had been sabotaged by their crews
in 1919. The Zeppelin company was saved from extinction by an order for
an airship, the USS Los Angeles (ZR-3), being placed by the US Navy; this airship conducted its first flight on 27 August 1924.[39] The Goodyear-Zeppelin partnership would continue up until the outbreak of the Second World War.[40]
In 1924, the British Government initiated the Imperial Airship Scheme, a plan to launch airship routes throughout the British Empire. This involved the construction of two large airships, the R100 and R101, paid for by the government. The R100 was privately built by Vickers-Armstrongs using existing commercial practices, with a design team led by Barnes Wallis, who had previously co-designed the R80.[41] After her first flight in December 1929, R100 made a successful round trip to Quebec in Canada in July and August the following year. The competing R101 was designed and built by the Air Ministry
and was supposed to encourage new approaches. R101 was severely
overweight, largely due to the decision to use diesel engines to reduce
fire risk, and it was decided to lengthen the airship's hull to increase
lift. In October 1930, R101 set off to Karachi
on its first overseas flight but crashed in northern France in bad
weather killing 48 of the 54 people on board, including the Secretary of
State for Air and most of the design team.[43]
Following this disaster, the R100 was grounded and was finally scrapped
in November 1931, marking the end of British interest in rigid
airships.[44]
During 1925, the Versailles restrictions were be relaxed by the Allies, enabling Dr Hugo Eckener,
the chairman of Zeppelin Luftschiffbau, to pursue his vision of
developing a zeppelin suitable for launching an intercontinental air
passenger service.[45] The sum of 2.5 million Reichsmarks (ℛℳ, the equivalent of US$600,000 at the time,[46] or $9 million in 2018 dollars[47]), was raised via public subscription, while the German government also granted over ℛℳ 1 million ($4 million) for the project.[49] Accordingly, Zeppelin Lufftschiffbau began construction of the first of a new generation of airships, the LZ 127 Graf Zeppelin. On 18 September 1928, the completed airship flew for the first time.[50] Shortly thereafter, DELAG commenced operations with the Graf Zeppelin, being enabled to launch regular, nonstop, transatlantic flights
several years before airplanes would be capable of sufficient range to
cross the ocean in either direction without stopping. During 1931, the Graf Zeppelin began offering regular scheduled passenger service between Germany and South America, a route which was continued up until 1937. During its career, Graf Zeppelin crossed the South Atlantic a total of 136 times.[51] The airship also performed numerous record-breaking flights, including a successful circumnavigation of the globe.[52]
The United States rigid airship program was based at Lakehurst Naval Air station, New Jersey. USS Shenandoah (ZR-1)
was the first rigid airship constructed in America, and served from
1923 to 1925, when it broke up in mid-air in severe weather, killing 14
members of its crew.[53] USS Los Angeles (ZR-3)
was a German airship built for the United States in 1924. The ship was
grounded in 1931, due to the Depression, but was not dismantled for over
5 years. A pair of large airships, the Akron and Macon, that both functioned as flying aircraft carriers were procured by the US Navy.[54] However, they were both destroyed in separate accidents. the Akron
was flown into the sea in bad weather and broke up, resulting in the
deaths of over seventy people, including one of the US Navy's proponents
of airships, Rear Admiral William A. Moffett.[55] Macon
also ended up in the sea when it flew into heavy weather with
unrepaired damage from an earlier incident, but the introduction of
life-jackets following the loss of the Akron meant only two lives were lost.[56][57]
LZ 129 Hindenburg carried passengers, mail and freight on
regularly scheduled commercial services from Germany to North and South
America. However, such services were brought to an abrupt end by the Hindenburg disaster of 1937. While the Hindenburg's sister ship, the LZ 130 Graf Zeppelin II, was completed, it would only perform thirty European test and government-sponsored flights
before being grounded permanently. During 1938, Luftschiffbau Zeppelin
was compelled to terminate Zeppelin manufacturing, while all operations
of existing airships was ceased within two years.[58] The frames of Graf Zeppelin and Graf Zeppelin II,
along with scrap material from the Hindenburg, were subsequently
scrapped that same year for their materials, which were used to fulfil
wartime demands for fixed-wing military aircraft for the Luftwaffe.[59]
Demise
Following
the Hindenburg disaster, the Zeppelin company resolved to use helium in
their future passenger airships. However, by this time, Europe was well
on the path to the Second World War,
and the United States, the only country with substantial helium
reserves, refused to sell the necessary gas. Commercial international
aviation was limited during the war, so development of new airships was
halted. Although several companies, including Goodyear, proposed
post-war commercial designs, these were largely to no avail.[60]
At an Air Ministry post-war planning session in 1943, a R.104 was
proposed to fulfill the Air Ministry Specification C.18/43. Despite the
presence of two airship stalwarts, Nevil Shute
and Wing Commander T.R. Cave-Brown-Cave the airship was not adopted.
The proposed R.104 was described by Lord Beaverbrook as "A pretty face,
but no good in the kitchen." The decision was to develop the Bristol Brabazon to meet C.18/43.[61]
The Brabazon was a much ballyhooed failure of the post war period.
Following the rapid advances in aviation during and after World War II,
fixed-wing heavier-than-air aircraft, able to fly much faster than rigid airships, became the favoured method of international air travel.
Modern rigids
The last rigid airships designed and built were built in the 1960s. The AEREON III
was constructed in Mercer County, New Jersey in the mid-1960s. It was
to utilize the method of "propulsion" developed and demonstrated by
Doctor Solomon Andrews in the 1860s as well as an aft mounted engine.
The AEREON III which had three side-by-side hulls flipped over during
taxi tests and was never repaired. A replacement, the AEREON 26
with a delta configuration was constructed and flight tested in the
early 1970s. The test program ended due to the expiration of the life
time of the drone engine. It was last reported hangared at the
Trenton-Robbinsvile Airport in New Jersey. It is not known whether it
still exists after almost 50 years. [62]
The Zeppelin company refers to their NT
ship as a rigid, but the envelope shape is retained in part by
super-pressure of the lifting gas, and so the NT is more correctly
classified as semi-rigid.[1]
Aeroscraft was certified airworthy by the FAA in September 2013 and has begun flight testing.[63]
See also
References
Citations
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