This model shows the largest airship of its time -- and perhaps the grandest, the most
luxurious craft ever to fly.
This is the British Airship R.101 built between 1924 and 1930 -- it was Britain's answer
to Germany's Zeppelin.
To give you an idea of its size compare it to this 747 -- one of the largest planes flying
today -- this miniature jet is the same scale as the airship model -- but the airship is
over 500 feet longer.
Now, the engineering of this airship fascinates me so much that . . .
...I wrote a book telling its story.
So, in this video I'll draw on the research for that book and use some of the old magazine
articles, newspaper clippings and . . .
... photos that I've gather over the last decade to
reveal the design choices of the ship's engineers, the daily life of a crew member,
and the opulence of the passenger areas.
But first, let's look at the grand plan for this airship.
It was to fly a regular route from England to India, connecting the countries in five
days -- ten days faster than by sea.
The airship's air rival, the plane, linked London to Karachi, then in India, in sixteen
days--but with frequent stops to refuel.
This airship was one of two built by Britain about a decade after the end of the war, when
they embarked on an ambitious airship building program.
They constructed the airship R.101, but also R.100 -- the "R" stands for "rigid"
-- which were to carry 50 passengers at a cost close to that of first class
in an ocean liner.
One proponent estimated a ticket from Australia to the United Kingdom would cost ten pounds.
The British spend over two million pounds in the 1920s to create commercial airships.
Their competitor was Germany's Graf Zeppelin.
It was forty feet longer, but R.101 had a larger cross section and so held 30 percent
more hydrogen and carried more passengers.
To put these ships in perspective here's the Hindenburg,
built about seven years after R.101.
The British intended R.101 and its sibling ship to be the first of a fleet.
Ultimately the British envisioned an "all-red girdle of air transport" that reached more
than halfway round the globe
-- red was the striking color of Empire territories on official maps.
Now, this map illustrates that vision.
At the bottom, in the legend, it reads: "Possible Imperial Airship Routes."
The British envisioned using airships to link the far-flung corners of their colossal Empire.
It covered a quarter of the world and encompassed a fifth of its population.
R.101 promised British dominance of the air: to rule the skies as British Dreadnoughts
ruled the seas.
They planned an infrastructure of towers centered on the Royal Airship Works: West to Canada
-- Halifax, Ottawa and Quebec.
And then south to Cairo, Karachi -- at the time in India -- Cape Town, Mombasa and Melbourne
in Australia.
This vision might seem grand to us today because we often think of lighter-than-air craft as
a novelty -- a hot-air balloon or the blimps used to cover the Super Bowl -- but these
are mere shadows of the greatest of all lighter-than-air craft . . ..
. . the airship.
Unlike an airship, balloon and blimps are both pressure vessels: their shape is maintained
by the pressure of the lifting gas.
In contrast, in an airship like R.101, it's shape is formed by a metal framework.
The metal skeleton houses the hydrogen-filled balloons, called gas bags, that lift the ship.
These bags are protected by a cloth cover stretched across the framework.
The cloth cover is not, of course, gas-tight, it's purpose, instead, is to keep wind,
rain, and sun from damaging the gas bags.
This structure enables an airship to travel faster and heft a much larger payload than
a blimp or balloon.
To construct such a craft required clever engineering in the 1930s, an era before plastics.
This is best reflected in the ship's fifteen giant gas bags that held over five million
cubic feet of hydrogen -- enough to lift about 170 tons.
To construct these gas bags the engineering staff searched for a material that was
impermeable to hydrogen -- a small molecule that is notoriously difficult to contain -- yet they also needed
a material that was lightweight, flexible, yet durable.
They investigated rubber, and viscose, an early synthetic fabric, coated with latex,
but when crumpled then inflated, each of these materials cracked and leaked.
So they settled for the traditional material used to construct airship gas bags . . .
. . . oxen. More specifically, part of the intestine of an ox.
The outside of an ox's intestine is lined with a fine membrane, called the cecum, which
is thin and flexible, and through which hydrogen seeps only slowly.
The grisly work of fabricating the gas bags
was done by the women of the Royal Airship Works.
In a room reeking of rotting meat, they soaked intestines, scraped away lumps of fat with
blunt knives, soaked the skins overnight, and then scraped again.
And then glued the pieces into larger and larger sheets -- no stitching, unlike for
zeppelins -- until they had enough to wrap about an air-filled form to construct a
gas bag.
To appreciate the magnitude of their task consider how many entrails were needed to
make a bag.
The cecum of an ox is about thirty inches by six inches, a little over a square foot,
yet one of R.101's gas bags when spread flat covers 30,000 square feet -- a square
about 175 feet on a side.
So, inside that yellow circle -- the tiny dash -- is a single cecum.
So, in total they glued together for a typical gas bag some 50 or 60 thousand entrails to
create a double-walled gas bags that held 37,500 cubic feet of hydrogen, yet weighed
a mere 30 pounds.
Flammable hydrogen to fill these bags seems a poor choice for an airship, compared to
inert helium -- in principle helium lifts 93% of the weight hefted by hydrogen.
You would think the lift would drop by only 7%,
which would be a small cost to pay for safety.
Yet, for a commercial airship, hydrogen is the only choice: it allows a lighter and thus
less expensive airship to be built.
Here's why.
Let's look at the lift of R.101 with both hydrogen and helium.
A ship like R.101 carries about five million cubic feet of lifting gas, that's a gross
lift of a little over 177 tons for hydrogen and for helium about 93% of that lift, or
about 165 tons.
But that's for pure hydrogen and pure helium.
In practice the purity is less than 100%, especially for helium and so you lose several
tons, which means helium lifts only about 88% of the amount lifted by hydrogen.
Now, let's calculate the amount of payload available.
The airship's framework weighs about 113 tons.
Next, the essential crew, fuel and so on needed to operate the airship take up another
44 tons.
So, in the case of hydrogen that leaves 13 tons of payload -- lift for passengers, fuel,
freight and so on, the stuff that makes an airship commercial -- while for helium that
net payload is an astonishing minus 7 tons.
That is, the airship could not left a payload, in fact, in this example -- which is typical
-- it could not even lift the crew and fuel.
In addition, helium was tremendously expensive, some seventy times the cost of hydrogen.
Typically helium was captured at gas wells in the United States and shipped to the United
Kingdom, while hydrogen was produced on-site from steam.
The Royal Airship Works used the Lane Process, in which steam was reduced to hydrogen by
passing it over metallic iron at a high temperature.
Once lifted by the hydrogen, the airship flew at an altitude of about 2,000 feet and at
maximum of about sixty miles per hour.
The ship was powered by five heavy-oil engines housed in cars underneath the airship: two
in the front ... two near the middle … and one near the tail.
Each engine was attended by an engineer.
In the rear engine car was Joe Binks.
He's on the right here dressed in his flying suit.
For eight hours at a time Binks kept the engines in repair as he waited for orders from the
control car.
The orders were communicated via a dial labeled standby, slow, half throttle, or full throttle
-- a rotating pointer indicated the proper action, the pointer's rotation was punctuated
by a bell.
Binks worked under harsh conditions.
This illustration from a popular magazine makes it seem roomy, but in reality he couldn't
stand up full height.
This photo of the car being built makes clear how little room Binks had: The man sitting
down shows where Binks could walk, or more often shimmy along the floor, to work on the
engine.
The man in the center stands where the engine will be placed.
In this photo with the engine installed, you can see the narrow space on either side where
Binks worked.
Imagine working within a few inches from this 650 horsepower monster -- it was originally
mounted on a locomotive -- it filled the car with a sound so deafening that Binks filled
his ears with plasticine and cotton to protect his hearing.
Yet as amazing as this is, the most stunning moment of his day was getting to and from
work: As the airship zipped along at 60 plus miles per hour, Joe Binks climbed from the
belly of the ship, down a ladder into the car.
The propeller spun with such force that its prop wash could lift him parallel to the ground,
turning him into a human flag tethered only by his tenuous grip.
Not only did the British develop this novel airship, they also created the necessary infrastructure.
For example, to land this giant ship, the British developed a mooring tower because
they thought ground landing too difficult for an airship of this size, although Germany
always used ground landings for its zeppelins.
The ship approached the tower, dragging a cable, which was then hooked to the tower
cables on the ground.
And then, at the tower's base, steam-powered winches pulled the ship toward the tower.
In fifteen or twenty minutes R.101 latched to an arm extending from the tower.
And then there was a flurry of activity inside the tower head as crew secured the ship.
The mooring tower could withstand a thirty-ton pull at its top.
Each of its four legs was embedded in a piece of concrete about twelve feet square that
extended six feet into the ground.
The tower offered an easy way to supply the airship with water, fuel, and hydrogen.
Huge pumps at the base could lift 5,000 gallons of water per hour and pump fuel at 2,000 gallons
per minute from the 10,000-gallon tank buried in the ground near the tower.
At the tower passengers boarded via a flexible bridge; they had a chill-inducing view of
the ground 170 feet below.
Yet their boarding could be even more thrilling: wheels on the bottom of the bridge allowed
it to revolve around the tower as the ship swung with the wind.
Unlike the Zeppelins that preceded it, R.101 had a novel feature: The passenger rode inside
the body of the ship, not in a car hung from the ship.
They built in an elegant dining room.
The cutlery and tableware were blazoned with the Royal Airship Works crest.
As passengers dined, the airship's steward stood against a wall with his back straight
and his chin raised -- his appearance was "spick and span," said a crew member.
He planned and organized the meals: his goal was seven-course meals comparable to those
of the best London hotels.
A large, brightly lit lounge the size of a tennis court spanned the width of the airship.
Its polished wood floor gleamed in the sunlight that spilled through giant windows
port and starboard.
On this floor the airship's designers planned for passengers to fox trot all night as the
airship flew to India.
At the end of each lounge were the ships' masterstroke . . . the promenade decks . As
passengers relaxed there they enjoyed a stunning panoramic view of the ground through large
glass windows tilted at forty-five degrees.
Beyond the passengers quarters R.101 had an unusual feature for an airship . . .
. . . :a smoking room . . .
. . . even though the ship carried over five million cubic feet of flammable hydrogen.
On these delicate gas bags rested many hopes and dreams,
yet the ship was not up to the task.
The Royal Airship's technical staff concluded, after studying data from R.101's test flights
over the United Kingdom, that the ship didn't have the lift to fly to India:
it was too heavy.
Partly this was because R.101 deviated from the time-tested principles used in zeppelins.
An airship framework of that era was composed of a series of rings.
Zeppelin engineers built strong yet light frameworks from thin, flexible circular rings,
which were then stiffened by radial wires drawn taut -- the wires functioned like the
spokes of a bicycle wheel.
In R.101 the wires were eliminated, and the rings were made much thicker.
This resulted in a heavier framework.
This decreased the amount of lift available for fuel so much so that on R.101's
return trip from India, the technical staff calculated that the ship would not be able
to complete the first leg of the 2,800-mile journey from Karachi to Ismailia.
R.101's fuel, they estimated, would run out over the desert in Saudi Arabia; the ship
would float with its engines stalled 500 miles or so from the mooring tower in Egypt.
To ensure that such a failure would not occur, the technical staff devised an audacious plan.
In this photo you can see the results of that plan.
At the top is the airship in late June and at the bottom six weeks later: the ship has
been lengthened from 735 to 777 feet.
The technical staff split the ship in two, inserted a section of framework and added
a gas bags to gain enough lift to carry fuel.
A short time after R.101 was split in two and lengthened it departed the Royal Airship
Works for India.
The airship departed the mooring tower on October 4th a few minutes after 6:30 p.m.
Greenwich mean time.
On board were 54 people: Forty-eight crew or members of the Royal Airship Works, and
the rest observers and dignitaries, including Britain's Secretary of State for Air.
The purpose of this flight was to demonstrate R.101's ability to travel to India, but
as it travelled across England, over the Channel and into France, the ship encountered bruising
winds and pelting rain.
Winds so fierce that often it travelled at a ground speed of only thirty miles per hour.
At a few minutes past two in the morning about 40 miles (64 kilometers) north of Paris, R.101
chopped through the turbulent air at an altitude of 1,200 feet, just below a layer of clouds.
The cover on top of the airship split open, the ship pitched down, the ship's crew used
the elevators to restore the ship to horizontal.
It was now 500 feet above the ground.
The control car signaled for the engine power to be cut and R.101 dove nose first to the
ground, then slide into a grove of hazel and oak trees.
It burst into flames as navigational flares ignited the hydrogen.
The imposing R.101, the great machine to connect the vast geographic sweep of the British Empire,
was now a tangle of debris on the ground.
Only the rudder at the stern still stood tall.
Rags and strips of fabric hung from it and fluttered in the wind, the center section
rocking on its hinges, swinging aimlessly.
Sixty feet in the air, at the tip of the stern, almost untouched by any flames, the ship's
RAF Ensign flapped in the wind -- the Union Jack on the flag was partly burned, but the
RAF roundel was intact.
Long gone from most of the framework were the delicate gas bags and plasticized cloth
cover -- both vaporized by the raging fire.
The polished metal exterior of a crushed engine car glistened in the flames.
The collision with the ground rotated the car 180 degrees,
its propeller now facing the wrong way.
From this debris, a charred crew member rose, but then fell back into the flames.
Inside an engineer, his body carbonized, still clutching a wrench in his hand.
The ground was littered with everyday articles: suitcases, fur-lined boots, charred shaving
brushes, a tin of cigarettes, and a ticking watch.
The stores were strewn on the ground: a few loaves of bread, and a still-labeled tin of
plums, its juice leaking from the can.
After a few moments the only sound was the hiss of rain evaporating as it struck the
smoldering wreckage.
One of the few survivors -- only six of the fifty-four survived -- was Joe Binks from
the rear engine car.
The rest were buried in a communal grave near the Royal Airship Works in the United Kingdom.
Each coffin was adorned with a small label fabricated from the metal of R.101's framework.
Fourteen of the plates bore names, but the others were never identified in the wreckage.
Their coffins read: "To the memory of the unknown airman who died on October 5th."
There's a little bit more to the story: in a sense the airship flew again.
The wreckage of R.101 was hacked to pieces using blow torches, chisels and metal saws.
The compacted eighty-ton framework was transported to Sheffield, where it was melted to scrap,
and then sold to the Zeppelin Company.
They used it to create the zeppelin LZ 129, an airship better known as . . .
the Hindenburg.
If you'd like to learn more, you can read my book: Fatal Flight: The True Story of Britain's
Last Great Airship.
You can listen for free to the complete audiobook.
Details at engineerguy.com/airship.
Or, you prefer you can listen right here on YouTube; I've listed the link in the end card.
I'm Bill Hammack, the engineer guy.
Không có nhận xét nào:
Đăng nhận xét