Gas Tubes for filling Airships, c.1914

Gas Tubes for filling Airships, c.1914


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Gas Tubes for filling Airships, c.1914

This picture shows British troops stacking the gas tubes needed to fill airships, c.1914.


Gas Tubes for filling Airships, c.1914 - History

We are specialized in industrial investments in the State of Kuwait and the Middle East since 1993, aiming at offering first-class products and services, as well as providing professional technical support and outstanding manufacturing practices. Our devotion to excellence is paralleled by our keen sense of responsibility for health, safety and the environment.

2 We are specialized in industrial investments in the State of Kuwait and the Middle East since 1993, aiming at offering first-class products and services

3 We are specialized in industrial investments in the State of Kuwait and the Middle East since 1993, aiming at offering first-class products and services, as well as providing professional technical support and outstanding manufacturing practices.

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How it's Made

Assembly of Wingfoot One began in March 2013 at Goodyear's Wingfoot Lake hangar. An international team of engineers and technicians from Goodyear and Germany's ZLT Zeppelin Luftschifftechnik worked side by side to complete the build project. Parts such as the tail fins and gondola were built in Germany and shipped to the U.S. for assembly. The balloon-like body of the airship – the “envelope” – is made of polyester with an innovative film from DuPont™ called Tedlar®, surrounding a semi-rigid internal structure, which differentiates this airship from previous Goodyear blimps.

The timelapse video shows the process of the Wingfoot NT from beginning to completion. Enjoy!


Now This Was a Gas Station: “90,000 Cubic Feet of Helium, Please, and Check the Oil”

On Blue Mound Road east of Meacham Field, behind a tall security fence, sit buildings that once housed the world’s first helium plant, which the Navy operated to fill its airships during the 1920s.

The surviving buildings of the plant today. The pond supplied water to cool the plant.

This photo shows the red-roofed building and two buildings just to the south in the aerial photo. The pond is out of frame on the right.

Fort Worth’s helium plant had its origin in an experimental helium-extraction station that the government built in north Fort Worth in 1918 during World War I. On December 4, 1917 the Dallas Morning News reported that a “chemical plant” that required substances found in natural gas was being built near north Fort Worth.

In 1918 the government paid Lone Star Gas Company $2 million to build a ten-inch pipeline from the Petrolia gas field in Clay County to the Fort Worth “chemical plant.”

For the sake of national security, the plant’s work was kept secret. Soldiers from Camp Bowie guarded the plant, which was surrounded by an eight-foot, knot-free wooden fence. Workers stored the extracted helium in cylinders and shipped them to New Orleans to be sent to the war front in France. But the armistice was signed before any Fort Worth-produced helium was shipped overseas. (Photo from Fort Worth, “The Convention City,” 1921, Amon Carter Museum.)

After the war the Navy continued to operate the plant, and on January 19, 1919 the Star-Telegram announced that the federal government had come clean and said it would construct the world’s first helium plant adjacent to the “chemical plant.”

The plant would be built on land that had belonged to early civic leader Major James Jones Jarvis. This 1895 map shows Major Jarvis’s home on the road leading to Blue Mound north of Saginaw. (This map detail has other stories to tell. To the east of Jarvis was Hodge Station, which had played a role in the Battle of Buttermilk Junction. To the west were tracts of land owned by Glenwood developer R. Vickery and Rush Loyd, who was almost hanged for another man’s crime but became one of the largest landowners in Tarrant County’s early African-American community.)

The new helium plant, built at a cost of $5 million ($65 million today), was the military’s only source of helium at a time when dirigibles had great strategic importance to the military. Helium, with 92 percent of the lifting power of hydrogen, is a safer gas, less flammable than hydrogen, which was used by Germany’s zeppelins, such as the Graf Zeppelin and Hindenburg.

The interior of the helium plant was a “mad scientist” maze of tubes, cryogenic cooling tanks, purifying tanks, gauges, and valves. The Navy even maintained an infirmary at the plant, stocked with gas masks. (Photo courtesy of Don Pyeatt.)

In 1924 workers added a mooring mast to the helium plant so that dirigibles could refuel. Helium was piped up the mast to a moored airship. Dirigibles drew large crowds as the ships sailed in to tie up at the mooring mast to refill their gas bags (made from laminated sheets of cow intestine obtained from the Fort Worth packing plants) and to stock up on gasoline and on food for their crews. (Photo courtesy of Don Pyeatt.)

The first airship to “fill ’er up” at the plant was the 682-foot-long USS Shenandoah, the world’s first helium-filled dirigible. The Shenandoah was front-page news on October 8, 1924 as its arrival was anticipated that night. During its moorage the giant airship would be guarded by members of the National Guard and Boy Scouts.

On October 8, 1924 a crowd estimated at twenty thousand turned out to crane its collective neck as the Shenandoah cast its elliptical shadow over Fort Worth and moored overnight at the helium plant. The dirigible left the next morning for the Pacific coast as it made the first flight of a rigid airship across North America.

Clips are from the October 9 and 10 Dallas Morning News.

The “dirigible mooring mast” and “helium production plant” appeared on the 1925 Rogers map of Fort Worth. (From Pete Charlton’s “1000+ Lost Antique Maps of Texas & the Southwest on DVD-ROM.”)

Exactly four years later, on October 8, 1928 the USS Los Angeles, with a crew of twenty-eight, refueled at the plant (󈭊,000 cubic feet of helium and 5,000 gallons of gasoline, please, and check the oil”) and moored overnight. The event drew a crowd estimated at twenty-two thousand. Photo, courtesy of Don Pyeatt, shows the Los Angeles passing over the packing plants.

On October 9 the Dallas Morning News showed the ship passing over Dallas headed to Fort Worth. The Magnolia Building, on the left, would not get its neon Pegasus until 1934.

As the Los Angeles neared Fort Worth from the south members of the crew dropped a note over the house at 1021 North Anglin Street in Cleburne. That address was the home of Hannah Rosendahl, mother of Los Angeles commander Charles Emery Rosendahl. Ironically, Rosendahl was not commanding the Los Angeles on that trip. He was in Germany observing the trials of Germany’s new Graf Zeppelin and would return to the United States aboard the Graf Zeppelin on its first Atlantic crossing. In 1937 Rosendahl, who had earlier served on the Shenandoah, would be in command of New Jersey’s Lakehurst Naval Air Station when the Hindenburg burned. (Photo from Wikipedia clip from October 9 Dallas Morning News.)

(The Shenandoah crashed in a storm in 1925 the Los Angeles was decommissioned in 1932.)

The Fort Worth helium plant also conducted experiments in the noble gases (helium, neon, argon, krypton, xenon, and radon), resulting in advances in oceanography, medicine, machining, and nuclear physics. Experiments at the plant also contributed to the development of neon lighting, changing forever the appearance of America after sundown.

Approximately 99 percent of the natural gas used at the plant to produce helium was “waste” but not wasted: Lone Star distributed it to customers.

The helium plant even had a basketball team in the Industrial League. After a disputed call on the court, it’s hard not to imagine helium plant team members arguing with the referee with voices like Mickey Mouse.

But by 1929 the Petrolia gas field was depleted, and the helium plant closed. Employees were transferred to a new helium plant at Amarillo. The Fort Worth facility was later occupied by the Federal Aviation Administration and then abandoned.

Today the site is occupied by a truck sales company, a towing company, and, each Halloween season, Hangman’s House of Horrors.


Flying with graphene

The rigid-frame LCA60T also has a rather special electric propulsion system that uses graphene. Its hybrid electric power system uses graphene-based ultracapacitors – batteries – that give the airship a boost when it needs to hover, lift cargo, and stabilise itself in bad weather.

"Our ultracapacitor technology driving the airships' electric power systems will ensure manoeuvrability and control, such as vertical take-off and landing ability, which will be vital for heavy-lift industrial applications," says Taavi Madiberk, CEO and co-founder of Skeleton Technologies, which manufacturers the graphene-based ultracapacitors.

Industrial production of the LCA60T is expected to start in 2020.


The gas laws

Over the past four centuries, scientists have performed many experiments to understand the common behaviors of gases. They have observed that a gas's physical condition—its state—depends on four variables: pressure (P), volume (V), temperature (T), and amount (n, in moles see our module The Mole: Its History and Use for more information). The relationships between these variables are now known as the gas laws, which describe our current knowledge about how gases behave on a macroscopic level.

But the relationships behind the gas laws weren't obvious at first—they were uncovered by many scientists examining and testing their ideas about gases over many years.

Gas pressure

We now understand that air is a gas made of physical molecules (for more information, see our module on Atomic Theory). As these molecules move about inside a container, they exert force—known as pressure—on the container when they ricochet off its walls. Thanks to this behavior, we can inflate car tires, rubber rafts, and Macy’s Day Parade balloons with gases. However, the idea that air is a substance made of molecules that exert pressure would have been a strange idea to scientists before the 17th century. Along with fire, water, and earth, air was generally considered a fundamental substance, and not one made up of other things. (For more information on this concept, see our Early Ideas about Matter: From Democritus to Dalton module.)

However, in 1644, the Italian mathematician and physicist Evangelista Torricelli proposed a strange idea. In a letter to a fellow mathematician, Torricelli described how he had filled a long glass tube full of mercury. When he sealed one end and inverted the tube into a basin, only some mercury flowed into the basin. The rest of the mercury stayed up in the tube, filling it to a height of approximately 29 inches or 73.6 centimeters (Figure 2). Torricelli proposed that it was the weight of air that pressed down on the mercury in the basin that forced the liquid up into the tube (this was one of the first known devices that we now call barometers).

Figure 2: Evangelista Torricelli experimenting with a tube of mercury and inventing the barometer. (Image from L'Atmosphere published in 1873.)

The Jesuit scientist Franciscus Linus had a different idea about what was holding the mercury up in the tube. He proposed that the mercury was being pulled up by "funiculus"—an invisible substance that materialized to prevent a vacuum forming between the mercury and sealed tube top.

The British scientist Robert Boyle disagreed, and came up with an experiment to disprove Linus’s funiculus idea. Working with the English physicist Robert Hooke, Boyle made a long glass tube that was curved like a cane, and he sealed off the short leg of the cane. Resting the curve on the ground so that both ends pointed up, Boyle poured in just enough mercury so that the silver liquid filled the curve and rose to the same height in each leg. This trapped air inside the sealed short leg.

Boyle then poured in more mercury and observed with “delight and satisfaction” that the trapped air in the sealed short end supported a 29-inch-tall (73.6 cm) column of mercury in the long leg—the same height that the mercury reached in Torricelli’s barometer. However, because there was no cap on the long leg, there could be no funiculus pulling up the extra mercury. Boyle reasoned that it must be the trapped air’s pressure (which he called “spring”) that pushed the mercury up those 29 inches.

To understand more about air’s pressure, Boyle poured more mercury into the curved tube. He recorded the height of the mercury column in the long leg, and the height of the trapped air in the short leg. After repeating these steps many times, Boyle was able to observe the relationship between the height of the trapped air—its volume—and the height of the growing mercury column—an indicator of the pressure in the tube. Even though scientists in Boyle’s time generally didn’t graph data, we can best see this relationship by graphing Boyle’s data (Figure 3).

Figure 3: The plot of Robert Doyle's data that he recorded during his experiment on mercury and trapped air in glass tubes. image © Krishnavedala

Boyle's law

Boyle’s data showed that when air was squeezed to half its original volume, it doubled its pressure. In 1661, Boyle published his conclusion that air’s volume was inversely related to its pressure. This observation about air’s behavior—and therefore, gas behavior—is a critical part of what we now call Boyle’s law.

Boyle’s law states that so long as temperature is kept constant, the volume (V) of a fixed amount of gas is inversely proportional to its pressure (P) (Figure 4):

Equation 1a

Figure 4: Boyle's law states that so long as temperature is kept constant, the volume of a fixed amount of gas is inversely proportional to the pressure placed on the gas.

Boyle’s law can also be written as:

Equation 1b

For a fixed amount of gas at a fixed temperature, this constant will be the same, even if the gas’s pressure and volume change from (P1, V1) to (P2, V2), because volume decreases as pressure increases. Therefore, P1 x V1 must equal the constant, and P2 x V2 must also equal the constant. Because they both equal the same constant, the gas’s pressure and volume under two different conditions are related like this:

Going back to that helium balloon shaped like Snoopy, Boyle’s law means that if you took the balloon deep under the ocean, poor Snoopy would shrivel because the pressure is very high and the helium would significantly decrease in volume. And if you took the balloon to the top of Mount Everest, Snoopy would get even bigger (and might even pop!) because the atmospheric pressure is low and the helium would increase in volume.

Which two variables describing a gas's state are inversely related, according to Boyle's law?

Charles's law

More than a century after Boyle’s work, scientists had figured out another important behavior of air: Air expands when heated, and hot air rises above cooler air. Taking advantage of this air behavior, the French brothers Joseph-Michel and Jacques-Étienne Montgolfier launched the first successful hot-air balloon in Paris in 1783.

The Montgolfiers’ balloon fascinated Jacques-Alexandre-César Charles, a self-taught French scientist interested in aeronautics. He had an idea about how to make an even better balloon. From his familiarity with contemporary chemistry research, Charles knew that hydrogen was much lighter than air. In 1783, Charles built and launched the first hydrogen balloon (see Figure 4 for an example of the balloon launch). Later that year, he became the first human to ride in a hydrogen balloon, which reached almost 10,000 feet above Earth.

Figure 4: Jacques Charles and Nicolas Marie-Noel Robert standing in their hydrogen-filled balloon waving flags, beginning their ascent in Paris. Thousands of spectators are gathered in the foreground to witness the first manned gas balloon flight.

Charles was very fortunate that he survived riding in a hydrogen balloon: On May 6, 1937, 36 people died when the Hindenburg airship, a dirigible filled with flammable hydrogen, caught fire and crashed to the ground. The airship’s flammable hydrogen gas may have been ignited by a lightning bolt or spark from static electricity, and the fire spread explosively throughout the ship in a matter of seconds.

While Charles never rode a balloon again, he remained fascinated with the gases inside balloons. In 1787, Charles conducted experiments comparing how balloons filled with different gases behaved when heated. Intriguingly, he found that balloons filled with gases as different as oxygen, hydrogen, and nitrogen expanded the same amount when their temperatures were heated from 0 to 80°C. However, Charles did not publish his findings. We only know about his experiments because they were mentioned in the work of another French chemist and balloonist, Joseph-Louis Gay-Lussac.

In 1802, Gay-Lussac published his results from similar experiments comparing nine different gases. Like Charles, Gay-Lussac concluded that it was a common property of all gases to increase their volume the same amount when their temperature was increased by the same degree. Gay-Lussac graciously gave Charles credit for first observing this common gas behavior.

This relationship between a gas’s volume (V) and absolute temperature (T, in Kelvin to learn more about absolute temperature, see our Temperature module) is now known as Charles’s law. Charles’s law states that when pressure is kept constant, a fixed amount of gas linearly increases its volume as its temperature increases (Figure 5):

Equation 3a

Figure 5: Charles's Law states that when pressure is kept constant, a fixed amount of gas linearly increases its volume as its temperature increases.

Charles’s law can also be understood as:

Equation 3b

For a fixed amount of gas at a fixed pressure, this constant will be the same, even if the gas’s volume and temperature change from (V1, T1) to (V2, T2). Therefore, V1/T1 must equal the constant, and V2/T2 must also equal the constant. As a result, the gas’s temperature and volume under different conditions are related like this:

This means that if we took the Snoopy balloon to the North Pole, the balloon would shrink as the helium cooled and decreased in volume. However, if we took the balloon to a hot tropical island and the helium’s temperature increased, the helium would increase in volume, expanding the balloon.

When different gases are heated up by the same number of degrees, their volume will

Avogadro's law

After his work on Charles’s law, Gay-Lussac focused on figuring out how gases reacted and combined. In 1808, he observed that many gases combined their volumes in simple, whole-number ratios. While we understand now that volumes of gases combine in whole-number ratios because that is how the gas molecules react, Gay-Lussac didn’t suggest this explanation. This was probably because the idea of whole-number molecular combinations had only recently been proposed by John Dalton, who was Gay-Lussac’s scientific rival. (For further exploration of how gas molecules react, see our Chemical Equations module).

It was the Italian mathematician Amedeo Avogadro who realized that Dalton’s and Gay-Lussac’s ideas complemented each another. Gay-Lussac’s claim that gas volumes combined in whole-number ratios resembled Dalton’s claim that atoms combined in whole-number ratios to form molecules. Avogadro reasoned that a gas’s volume must then be related to the number of its molecules. In 1811, Avogadro published his hypothesis that equal volumes of different gases have an equal number of molecules.

Avogadro’s hypothesis was ground-breaking though largely overlooked. The mathematician rarely interacted with other scientists, and he published his hypothesis with mathematical expressions that were unfamiliar to chemists. He also didn’t publish experimental data to support his hypothesis.

It was 47 years before Avogadro’s hypothesis would be broadly recognized. In 1858, a former student of Avogadro, the Italian chemist Stanislao Cannizzaro, published an influential work on atomic theory. This work drew on Avogadro’s hypothesis and presented experimental data supporting the hypothesis.

Avogadro’s law is based off of Avogadro’s hypothesis. Avogadro’s law states that at a constant pressure and temperature, a gas’s volume (V) is directly proportional to the number of molecules (n, in moles) (Figure 6):

Figure 6: Avogadro's Law states that at a constant pressure and temperature, a gas's volume is directly proportional to the number of molecules.

We know that a Snoopy balloon filled with helium will float above the parade, while the same balloon filled with air will drag along the ground. While helium and air are different in many ways, Avogadro’s law means that if we compared the number of helium molecules and the number of air molecules needed to inflate the same Snoopy balloon, we would find that the numbers are the same.

According to Avogadro's law, 1 liter of toxic carbon monoxide gas and 1 liter of flammable hydrogen gas both have the same:


Weapons Check | Anti-Zeppelin Dart

On the night of January 19, 1915, two German Zeppelin airships ponderously dropped their small bomb-loads on Great Yarmouth and King’s Lynn on the eastern coast of England, beginning what was, in effect, the first sustained strategic bombing campaign in history. The British military immediately started looking for ways to bring down the new threat. Focusing on the dirigibles’ highly flammable hydrogen gas filling, Engineer Lieutenant Commander Francis Ranken of the Royal Navy invented the Ranken dart—essentially a hand-deployed anti-Zeppelin incendiary device. The dart consisted of a 13-inch-long tinplate tube capped with a penetrating tip and filled with a combustible mixture. The intention was to drop the darts, loaded in 24-round boxes, from an airplane flying above the Zeppelin. As each dart pierced the airship’s skin, its three spring-loaded metal arms would open, pulling up an igniter rod inside the dart and detonating the explosives inside (in much the same way as dragging a match head across a rough surface causes it to ignite). The engineering was ingenious, but the devices were not popular with pilots in the Royal Naval Air Service and the Royal Flying Corps (nor with the civilians on whom they might inadvertently fall). The Ranken darts were also inaccurate—so much so, in fact, that they may never have been solely responsible for downing an airship. MHQ

CHRIS McNab is a military historian based in the United Kingdom. His most recent book is The FN Minimi Light Machine Gun: M249, L108A1, L110A2, and Other Variants (Osprey, 2017).

This article appears in the Summer 2017 issue (Vol. 29, No. 4) of MHQ—The Quarterly Journal of Military History with the headline: Torpedoed!

Want to have the lavishly illustrated, premium-quality print edition of MHQ delivered directly to you four times a year? Subscribe now at special savings!


An Illustrated History Of Gas Masks

The gas mask has a history that dates back thousands of years, though it wasn't until World War I that it became nightmare fodder for Doctor Who and countless other stories. Here is a sometimes terrifying history of the gas mask, from its beginnings through the present day.

Playing leapfrog, 1934

Above. Able seamen at the Royal Navy Anti-Gas School at Tipnor, Portsmouth play leapfrog wearing gas masks, to accustom them to carrying out strenuous tasks in respirators, on January 22 1934.

(Photo by William Vanderson/Fox Photos/Getty Images)

The common sponge, ancient Greece

"The common sponge was used in ancient Greece as a gas mask, a compress, a contraceptive – and, of course, for bathing."

Banū Mūsā Gas Mask, c. 850 A.D

This gas mask was designed by the Banu Musa brothers in Baghdad, Iraq to protect workers working in polluted wells. The device was mentioned in the brothers book "Book of Ingenious Devices" that describes 100 inventions.

(Illustrations are from the brothers' book, but not about the gas mask, via Wikimedia Commons 1 - 2 )

Plague Doctor's Mask

The bird-like beak mask was often filled with sweet or strong smelling herbs or spices – lavender, mint, camphor or dried roses. They've believed it would banish the evil smells.

Alexander von Humboldt's mask, 1799

It was the first device with respirator, invented for miners by a Prussian mining official Alexander von Humboldt.

A smoke protecting apparatus for firemen by John and Charles Deane, 1823

In the early 1820s John Deane have seen a burning stable with trapped horses in it. To get through the smoke and rescue all the horses he put on an old knight-in-armor helmet air-pumped by a hose from a fire brigade water pump. The saving was successful, and in 1823 John and Charles Deane have invented the Smoke Helmet:

"An apparatus or machine to be worn by persons entering rooms or other places filled with smoke or other vapour, for the purpose of extinguishing fire or extricating persons or property therein."

The device was a single copper helmet with a long leather hose attached to the rear. A long leather hose was attached to the rear. Five years later it was converted for underwater use.


Hydrogen discovery

Robert Boyle produced hydrogen gas in 1671 while he was experimenting with iron and acids, but it wasn't until 1766 that Henry Cavendish recognized it as a distinct element, according to Jefferson Lab. The element was named hydrogen by the French chemist Antoine Lavoisier.

Hydrogen has three common isotopes: protium, which is just ordinary hydrogen deuterium, a stable isotope discovered in 1932 by Harold C. Urey and tritium, an unstable isotope discovered in 1934, according to Jefferson Lab. The difference between the three isotopes lies in the number of neutrons each of them has. Hydrogen has no neutrons at all deuterium has one, while tritium has two neutrons, according to Lawrence Berkeley National Laboratory. Deuterium and tritium are used as fuel in nuclear fusion reactors, according to Los Alamos.

Hydrogen combines with other elements, forming a number of compounds, including common ones such as water (H2O), ammonia (NH3), methane (CH4), table sugar (C12H22O11), hydrogen peroxide (H2O2) and hydrochloric acid (HCl), according to Jefferson Lab.

Hydrogen is typically produced by heating natural gas with steam to form a mixture of hydrogen and carbon monoxide called syngas, which is then separated to produce hydrogen, according to the Royal Society.

Hydrogen is used to make ammonia for fertilizer, in a process called the Haber process, in which it is reacted with nitrogen. The element is also added to fats and oils, such as peanut oil, through a process called hydrogenation, according to Jefferson Lab. Other examples of hydrogen use include rocket fuel, welding, producing hydrochloric acid, reducing metallic ores and filling balloons, according to Los Alamos. Researchers have been working on developing the hydrogen fuel cell technology that allows significant amounts of electrical power to be obtained using hydrogen gas as a pollution-free source of energy that can be used as fuel for cars and other vehicles.

Hydrogen is also used in the glass industry as a protective atmosphere for making flat glass sheets, while the electronics industry, it is used as a flushing gas in the process of manufacturing silicon chips, according to the Royal Society.

This true-color simulated view of Jupiter is composed of 4 images taken by NASA's Cassini spacecraft on December 7, 2000. The resolution is about 89 miles (144 kilometers) per pixel. Credit: NASA/JPL/University of Arizona


Are Airships for Real?

In June 1937, the Army Air Corps walked away from lighter-than-air aviation. The AAC had been operating two airship and two balloon squadrons, but Congress and Army leaders, facing tight budgets, decided they had to go. Maj. Gen. Oscar Westover, the AAC Chief, turned over the fleet to the Navy and got the nation’s premier air arm out of the blimp business—seemingly forever.

Airships virtually disappeared from public consciousness over the next 70 years. However, they did not completely die out. Lighter-than-air systems—in small numbers and operated in other armed services or agencies—all the while have occupied niche roles in US national defense.

Now, to the surprise of virtually everyone, airships seem to be making a modest comeback, more than a century after the Army fielded its first models. Some new types are being flown by the Air Force.

These are not the blimps of old, which were unwieldy, unreliable, and often dangerous to life and limb. The new types could take on missions such as resupply of American ground forces overseas and defense against cruise missiles.

This new breed of airships ranges from unmanned, high-altitude aerostats designed to stay in one place to experimental giant cargo airships capable of carrying several times the tonnage hauled by a C-5 airlifter.

Sausage Squadrons

In World War I, “sausages” (the term used in the early days of ballooning) were commonly used for artillery spotting and other observations. In fact, the first unit in the US Army Air Service to be declared operationally ready was a balloon company that came up to the Western Front in late February 1918.

In the US military, the Navy dominated the lighter-than-air community. It kept balloons in use for coastal defense through World War II. Naval aviators in those days opted either for the lighter-than-air or the heavier-than-air track—each with its distinct service badge.

In the early days, the reputations of airships were irremediably tainted by highly publicized accidents. The Navy’s USS Shenandoah went down in a 1925 storm, with much loss of life. It was the specific event that provoked Army Brig. Gen. William Mitchell to accuse the Army and Navy of treasonable aviation management. (See “The Keeper File: The Blast From Billy Mitchell,” July, p. 28.) Britain’s R101 airship crashed near Beauvais, France, in 1930. Then came the Hindenburg disaster at Lakehurst, N.J., in 1937. The hydrogen-filled dirigible exploded in an immense fireball.

The Navy’s airship investments created enough of an industrial base to support production of what came to be the legendary Goodyear blimps. Goodyear built its first blimp—named “Pilgrim”—in 1925.

The Navy had 10 airships at the outset of World War II. Thereafter, production expanded and, in 1945, the service could call on 141 operational K-type blimps, used mainly for open ocean escort. According to an official history, these Navy aircraft escorted some 89,000 surface ships without the loss of a single vessel to enemy submarine attack. The Navy kept some semblance of a program until 1962.

Today’s developments could propel airships into military operations over the next decade. New technologies—and changing geopolitics—are making airships relevant for such missions again.

Airships have already returned to military service in a traditional role: surveillance. In 1980, North American Aerospace Defense Command inaugurated use of the Tethered Aerostat Radar System (TARS). This Air Force airship operates on the southern border of the United States.

The aerostat is a slimmed-down cousin of the original airships. Filled with helium, it looks and performs like an unmanned cross between a blimp and a balloon. A cable provides a tether and power sufficient to keep the aerostat airborne for months at a time. A TARS aerostat can reach an altitude of 12,000 feet while carrying a payload of sensors weighing more than a ton.

Given its high-altitude vantage point, the radar on the aerostat can detect targets such as small airplanes at a distance of 230 miles. Positioning several aerostats on the border forms a steady and cost-effective radar screen. The TARS aerostats were first used as radar platforms for drug interdiction. They picked up a new homeland security mission after the Sept. 11, 2001 attacks.

Tactical Aerostats

Today two tactical aerostat variants are assisting US troops in other ways. REAP—the Rapidly Elevated Aerostat Platform—is a joint Army and Navy program. Just 25 feet long, REAP is designed to operate 300 feet above the surface with day and night electro-optical sensors.

Big brother to REAP is the newer Rapid Aerostat Initial Development (RAID) system. It’s twice as big and can carry payloads of sensors to 1,000 feet. RAID’s main purpose is force protection.

The need for defense of US soil from cruise missile attack opened up an entirely new mission for sophisticated aerostats. The Joint Land Attack Cruise Missile Defense Elevated Netted Sensor (JLENS) system dates to the mid-1990s. JLENS was conceived as part of the solution to the challenge of detecting and tracking low-flying cruise missiles.

Defending against cruise missile attack calls for continuous surveillance with no gaps. While high-end systems such as the Airborne Warning and Control System aircraft and the Aegis system are more than capable of picking up the low-fliers, the trick is keeping sets of E-3s or Navy cruisers in place all day, every day.

An expanded aerostat system could in theory remain on guard continuously at much lower cost. JLENS posited a two-layer system to perform the early over-the-horizon detection and fire-control missions for cruise missile intercept. In theater operations, the JLENS airship would be accompanied by a mobile mooring station and a separate processing station for the radar data.

According to a recent Congressional Research Service report, “JLENS is seen by some to be an important part of DOD’s network-centric warfare approach, because it is the centerpiece of a larger attempt to seamlessly link together numerous sensors across services to build a ‘single integrated air picture’ that will enable effective cruise missile defense.”

Pushing aerostats to the next level entails moving from the 12,000-foot altitudes of TARS to the “near space” altitudes of about 70,000 feet. Radars permanently positioned at that height could greatly expand the integrated air picture of activities on Earth.

In theory, a small band of high-altitude airships could survey the entire United States, including the interior, and do it well above commercial and military aircraft lanes.

The operational concept calls for an airship to carry an over-the-horizon radar, much like a low-flying satellite would do. Ten high-altitude airships could provide overlapping coverage of an entire US coast.

An operational airship would have to be about 25 times the volume of a Goodyear blimp for the helium to function at 70,000 feet. The huge airship may also become the structure for the radars it carries. An active electronically scanned array radar with long antennae on the sides of the giant blimp could provide stunning power, coverage, and reliability. The Defense Advanced Research Projects Agency is researching the concept.

The Air Force Research Laboratory has funded experimental research on a high-altitude airship capable of remaining on station as long as one year. To keep a geostationary position, the airship would need its own fuel cell—still under development—and thrusters to reposition it in the winds at 65,000 feet, according to Purdue University professor John Sullivan.

Hybrid Airships

These craft face some of the same challenges that bedeviled the zeppelins of old. Thunderstorms brought down USS Shenandoah, but the classic summer storm might be nothing compared to the turbulence at 70,000 feet.

To get around this problem, the high-altitude airship would, in theory, be able to “fly” under its own power, change altitude, and reposition itself to avoid dangerous conditions.

Plans call for the high-altitude airship demonstrator to fly in 2009.

The real successors to the airships of bygone days may be a new crop of hybrid systems able to carry vast quantities of cargo. DARPA, the Navy, and the Army all set hybrid airship research in motion in recent years.

The hybrid airship is technically heavier-than-air. It combines static lift from the buoyancy of helium gas with aerodynamic lift derived from the lifting body shape of the pressure envelope. Theoretically, the combination makes huge payloads possible.

Hybrid airships would take off and land at low airspeeds that allow flight controls to remain effective. Engine-driven propellers and vectored thrust increase control and handling options.

One hopes that airship operations of the future do not become as notorious as those of the early 20th century. After World War I, military experimentation began in earnest. The resulting trail of disaster was long indeed.

The Army Air Service got things off to a bad start with Roma, a 410-foot-long dirigible acquired from Italy in 1920. In a test flight on Feb. 21, 1922, Roma struck some high-voltage wires, which touched off its hydrogen gas. The explosion killed 34 of 45 crew and civilians on board.

Thereafter, however, the Navy suffered a string of spectacular mishaps:

USS Shenandoah was built for coastal defense and fleet surveillance. The airship was a popular sight, flying over state and county fairs until it went down during one such publicity tour in September 1925. Fourteen crew members died.

USS Akron ran into a violent storm and crashed into the Atlantic in April 1933, and a smaller J-3 Navy airship crashed during the rescue attempt.

USS Macon encountered a storm off California and crashed into the Pacific in February 1935.

Such problems left the Navy more than willing to sign a contract in October 1935 for the new LZ-129 Hindenburg to operate from NAS Lakehurst, N.J. The Navy swapped landing rights and servicing in return for seats for Navy observers on the homeward flights.

Hindenburg was the largest airship ever to fly. Sixteen gelatin-coated gas cells encased the hydrogen lifting gas. Four diesel engines provided power for liftoff and cruise. Hindenburg was a passenger liner that made 10 successful trips from Frankfurt to Lakehurst during 1936.

The airship’s course took it across the Atlantic at about 1,000 feet and then over Manhattan on the way to Lakehurst.

On May 6, 1937, disaster struck. While Hindenburg was trying to dock at the mooring tower, it caught fire at the stern. Hydrogen-fed flames consumed the airship in a little over a minute, killing 36 passengers and crew. Many of the survivors owed their lives to the sandy soil of the landing area, which cushioned their falls from the burning wreckage.

The impetus behind this new activity is a recurring requirement: cheaper intercontinental lift for heavy ground forces. Since the end of the Cold War, the Army has been seeking ways to deploy units more quickly. The ideal solution is a vertical takeoff and landing vehicle that could operate in austere locations without large runways.

Could hybrid airships fill the bill? That’s what DARPA set out to explore with a program called Walrus. Requirements called for an airship to deliver a payload of 500 tons over a distance of 13,800 miles in less than seven days.

In 2005, DARPA awarded two formal contracts for competitive development of a behemoth Walrus cargo airship. Lockheed Martin squared off against newcomer Worldwide Aeros Aeronautical Systems.

Then, Congress zeroed out funding. DARPA opted to close down Walrus after completion of the first phase.

This does not spell the end for hybrid airships, however. Lockheed Martin flew a test hybrid airship dubbed the P-791 in California in early 2006.

Observers described the P-791 as the size of three 200-foot-long Fuji blimps joined together. It has air cushions for landing gear. Reportedly, airship pilots took hovercraft training to get a feel for the ground handling of the demonstrator.

Promising as some of the demonstrators may be, the new airships still have hurdles to overcome. These include ground handling difficulties, development costs, and lingering questions about vulnerability in a combat environment.

The cargo hybrids face integration challenges, and even the high-altitude airships have to contend with thermal and ozone factors and days when winds in the stratosphere top 115 mph.

“They’re not cool,” quipped retired Gen. John P. Jumper, former Air Force Chief of Staff, who also saw their value.

A recent Congressional report estimated that 32 companies across Europe, Asia, and North America are designing and manufacturing airships, mostly for commercial or experimental purposes.


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Comments:

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