NARRATOR: Chaos in
Guadalajara, Mexico when the city's streets explode. An airplane crash
outside of Paris that ranks as one of
the worst in history. Two dams in Italy collapse,
engulfing a village in a tidal wave of sludge. Students and teachers
in a small Texas town are entombed in the
rubble of their school. An oil tanker runs aground
off the coast of England and introduces the
world to the devastation of the first super spill. Now, engineering disasters
on "Modern Marvels." [music playing] On the morning of April 22,
1992, a series of explosions rocked the streets
of Guadalajara. I told my family,
get out here. Something happened. I don't know what,
but get out here. NARRATOR: Starting
just after 10:00 AM, and lasting over four hours, at
least five separate explosions devastated nearly 20
blocks of the city. LILIA MEZA: We don't know what
happened in the city, just was the smoke, was
explosion, was all the-- the fire, and a lot
of people's down. NARRATOR: News of the massive
devastation traveled to Texas, and on the request of
the Mexican consulate there, one Houston based team
was asked to visit the disaster site. I put together a
group of firefighters, some medical people, some
people from public works. Our mission was to
see what was needed, and also, to determine what
caused the explosion if we could. We figured, we'll start
at the outer perimeters where the devastation is
and try to work ourselves to the epicenter. We walk around a corner,
and there's this giant ditch about 15 feet deep, in
some areas, even deeper, and it was just mind boggling
to walk out into that area and see the first 10
feet of the houses gone. NARRATOR: A jagged
trench exacting the path of the main sewer line
had devoured everything in its path, including cars,
buses, and pedestrians. Adjacent homes and businesses
were reduced to rubble. The scene resembled a war zone. By official counts,
there were 215 dead, 1,600 buildings destroyed,
and 1.500 people injured. The massive explosion had
originated in the sewer main buried underneath
the city streets. EDDIE CORRAL: The explosion
came through the pipe, came through the dirt,
went straight up, and then all the debris came back down. It was something like a-- I just never seen before. 40 years in the fire
department, had seen a lot. Never seen anything
quite like that. RAMIRO AGUILAR: Most of the
people concluded we were-- there were about 3,000 dead,
but the official figures are around 200. They started to remove
the debris 24 hours after the shock, so they had
no way to separate bodies from debris. NARRATOR: Days before the
catastrophe, residents in and around Sector Reforma,
a working class neighborhood located in southeastern
Guadalajara, had lodged nearly 600
complaints of a strong gasoline odor emanating from the sewers. There was alarm. There was phone calls to the
fire department the night before because of the
strong smell of gasoline, and there was a
little investigation of what was going
on, and everyone was told to go back to bed. And less than 12 hours
later, it all blew up. [explosion] NARRATOR: In the wake
of the destruction, residents demanded
answers to what went wrong and why the area had
not been evacuated. The government tried to find
some answer to give to the-- the-- to the people,
but they-- they created a couple of theories
about vegetable oil company, and there was no
believable answer. NARRATOR: Despite what
they were being told, it was obvious that the
substance that caused the explosion was gasoline. And in Mexico, all of the
gasoline comes from one source. RAMIRO AGUILAR: Pemex is the
only oil producer in Mexico. It's a monopoly. And they produce and sell
every liter of gasoline. NARRATOR: Somehow, large
quantities of gasoline had seeped into the sewer line,
creating a massive pipe bomb. Three years earlier, the
subway was built a few blocks away, and it had to cross
where the main sewer goes, so they created a U-turn
underneath the subway rails. NARRATOR: Much like a trap
under a household sink which causes a water
plug that prevents sewer gases from entering the
house, an airlock was formed in the sewer itself. MARVIN ENGLAND: This gasoline
is flowing through these sewer pipes underneath the
city, and finally, it reaches the right ignition
point, the vapor density in the air, and possibly,
someone throws a lighted-- you know, like a
cigarette butt that's burning out into a sewer, and
boom, off goes the explosion. It sends out a
pressure wave that pushes the rest of the
vapors and the liquid gas farther down through
the sewer system. Maybe it's too rich
for a few seconds, and then it'll finally reach
the right ignition point, and the burning gasoline then
ignites the next section, it explodes, and it keeps
moving and moving and moving. NARRATOR: The
series of explosions did not go beyond the
U-turn in the sewer pipe. If there was no air
lock, the explosion could have gone
farther, or there could have been no explosion,
but just a huge fire inside the sewer,
but not an explosion, because the heated
air could have flown. There was no option
because there was this U-turn, this airlock. NARRATOR: With the damage
assessed and cause determined, the team from
Houston just needed to locate the origin of
the gasoline in the sewer. MARVIN ENGLAND: We went back
to the devastation area, and while we were there, chief
saw a pickup truck with workers that were going to leave,
and he told the officials, said, why don't we
catch that truck and just go with those guys,
hoping that it would take us to this Pemex plant that we
heard people talking about. So we jumped in the back of that
pickup truck with the workers and went on to the Pemex plant. When we got out and started
checking our equipment, that's when the hydrocarbon
sniffers started going crazy and started saying that
explosion was imminent, and the farther we went,
the smell of the gasoline was just horrendous. And you look at the ground,
and the ground looks wet, but it's not wet with water. The ground's wet with gasoline. The ground is completely
permeated with gasoline that leaked up through the
soil from the pipes that were underground, and
then we definitely knew we had found
where the leak was. Right in front
of the plant was where the pipe ran
over the sewer line, and that pipe was
leaking in the ground, and the ground was saturated. It was down at least 8
feet solid with gasoline. We saw them actually taking
out the pipe that was rusted and leaking and putting in--
trying to put in a new pipe. NARRATOR: The useful life
of underground steel pipes, even when coated and
wrapped, generally does not exceed 30 years
without inspection, repair, or replacement. The pipe was just
really, really rusted, and big holes in
it, and the pipe they were going
to replace it with wasn't that much better shape. They had whitewashed it,
put some whitewash on it. And I don't know if that was
going to be just temporary, or just what that--
what that was about. We found the cause. We found the origin of the gas. We felt pretty good about
accomplishing our mission and gave our report
to the consulate. NARRATOR: With their
mission accomplished, the team returned to Houston. In Guadalajara, a
separate investigation was already underway. The President of Mexico came
here, and he said, three days. 72 hours, and I want to
know who is responsible. NARRATOR: With a slightly
different account than the Houston delegations,
the Mexican government's inquiry concluded that an iron
water main had been illegally installed, intersecting
and establishing contact with a 12-inch steel pipeline. This dissimilar metal-to-metal
contact in a moist environment caused corrosion to both lines. A half inch hole was created
in the gasoline pipeline, allowing an estimated
150,000 gallons of gasoline to leak into the soil. And a little hole, and
from this little hole flew or dumped all the
thousand and thousand of liters of gasoline. This is the official version
of all the investigation. NARRATOR: Upon completion
of the investigation, the Mexican courts
ruled that no one was at fault for the
explosions, and the case was unequivocally closed. RAMIRO AGUILAR: The big question
is, could it happen again? When you're in the
middle of a situation, you don't care about who did
what or play a blame game. What we want to do is find
out where's it coming from, why did it happen, is
it gonna happen again? Pemex offered
unofficially help and money, but they never accepted
any of the responsibility of this explosion. [music playing] RAMIRO AGUILAR:
After we came back, we had no idea what happened
after that, because it seemed like it was just-- it dropped
off into a black hole. Nobody really knew what
was going on down there, or like, it had never happened. I just have this memory
that I carry with me. I know what I saw. I know what I experienced. And it wasn't good. NARRATOR: Remnants of the
destruction and memorials to the victims of
the 22nd of April serve as constant reminders
of this massive tragedy that, unfortunately, is little
known outside the streets of Guadalajara. McDonnell Douglas's
mighty DC-10, built to compete against rivals
Lockheed L-1011 and the Boeing 747, was one of the workhorses
of the world's commercial jet fleet for 20 years. But in the early 1970s, the new
wide body design of the DC-10 turned what could have been
a survivable malfunction in a smaller plane into a
deadly engineering problem. The cargo door could appear
to be closed and latched when, in fact, it was not. The Federal Aviation
Administration determined that this
unsafe condition resulted in one of the worst
aviation disasters in history, and began the negative public
perception of the DC-10 that it would never escape. The DC-10 was--
really got a bad rap. I mean, it was the Corvair
of the airplane industry. NARRATOR: The DC-10 was the
Douglas Aircraft Company's first and only wide-bodied
commercial airliner. The jet featured a
spacious cabin design with two aisles and
three rows of seats, but the air pressurization
systems for the enormous cabin were similar to those
used in smaller planes. A lot of-- of the design
features of the wide-bodied aircraft were just scaled up
from the previous narrow-bodied airplanes. NARRATOR: The DC-10 was
a short range jumbo jet, capable of carrying
343 passengers. It was less expensive
than its rivals, and soon became the
nation's most popular wide-bodied aircraft. But in 1972, less than two
years after its introduction, a DC-10 flying over
Windsor, Canada exhibited the first signs
of problems in the new jet. There was an incident
involving a DC-10 departing Detroit. As it was climbing,
the cargo door flew off and some cargo went
out of the aircraft. The aircraft had considerable
control difficulties. Because the loss of the
door, depressurization had collapsed the floor in
the back of the airplane. NARRATOR: As the
cargo door came off, there was an explosive
decompression of air in the cabin
escaping out of the hole. The pressure of the
massive volume of air was so heavy that the
cabin floor gave way. Even though control cables
running under the cabin floor were damaged, the pilots
were able to land the plane, and no life was lost. It was later determined
that the vent door, a secondary locking
device on the cargo door wasn't secured before takeoff. STEVEN LUND: When we got
the report from the baggage handler, he said he was
having a hard time closing the vent door, so he had
to put his knee or his-- knee on it to close the
door, and he forced and bent the mechanism such
that the light went off in the cockpit, and-- and the vent door closed. So the cargo door apparently
looked like it was sealed, and the door itself was closed,
but it wasn't properly latched. NARRATOR: The torque tube in the
locking mechanism of the cargo door could be bent
by human force. Once bent, the tube would
allow the door to close, even though it was
not properly latched. RON SCHLEEDE: The
NTSB wrote a report and issued safety
recommendations to the FAA requesting
that the FAA consider certain modifications
to the door and to the aircraft
to prevent the damage from a loss of the door. NARRATOR: The FAA allowed
for the modifications to be carried out on
a voluntary basis. Although most carriers
repaired their aircraft, some, especially those operating
outside the US, did not. On March 3, 1974, a
Turkish Airways DC-10 departed from Paris. The first few minutes of
the flight were routine, but suddenly, as the
plane reached 13,000 feet, the cargo door blew out. The immense force of
the pressurized air in the cabin as it
rushed out the cargo door buckled the floor. STEVEN LUND: When
the floor collapsed, some of the seats actually
detached from the floor and went out the door,
out the airplane. NARRATOR: Vital control
lines for the plane ran just under the cabin floor. They were instantly severed. What happened is
that the airplane, because the-- because
the floor collapsed and-- and actually moved the
controls mechanically, the crew cannot overcome
that mechanical difference, so the airplane came down. NARRATOR: The plane slammed
into trees in a forest. All 346 passengers were killed. Investigators soon discovered
that the cause of the crash was almost identical to
the accident in Windsor. STEVEN LUND: According
to the French report, the door was not
closed properly. That's why it came open. And they could not find
evidence of the fixes that we had put out after
the Windsor accident in the wreckage. RON SCHLEEDE: In both
cases, the ground personnel forced the door or
forced the handle, and because there was a bending
and compliance in the push rods, the door-- the handle
actually closed, therefore, indicating that the cargo
door was closed and latched. NARRATOR: After the
Turkish Airways disaster, the FAA mandated that the
cargo door on DC-10s operating in the US be modified. There were several
design changes made to ensure that the
operator of the door could not close the vent
door unless the latches were in the proper position. As a result of
the Paris accident, there was a fix put on the door
which included what they called a feedback loop. Not only was there a rod
going from the handle to the latch pins, and to the
small pressurization door, there was a feedback loop. Another set of rods were
connected back to the handle to show that the latch pins
had, in fact, engaged properly. NARRATOR: The crash also
resulted in a mandated design change for not just the DC-10,
but all wide-bodied aircraft. These planes had small vents
between the cabin floor and the cargo area, designed
to equalize pressure between the two areas if needed. The venting system was
adequate in smaller planes, but couldn't equalize the vast
volume of air in a wide body. That design feature worked
well on the narrow-bodied older aircraft, and it was the same
design used for the wide body, however, the scaling up led
to the problem that this tremendous volume of air now
in a wide-bodied airplane, those traditional vents
were not sufficient, and that's why we had
the collapse of the floor in the two DC-10s. NARRATOR: The fix entailed
installing additional vents in the floor of the cabin
which would allow air to rapidly equalize. If you have a pressure
change, such as what would occur as a result of some-- such as a cargo door opening up,
then these doors would open up. They're kind of spring-loaded,
and they basically open up. And what they do is
allow, then, the pressure to vent around the outside
of the floor and it keeps that whole
floor from collapsing. NARRATOR: A series of unrelated
accidents involving DC-10s, including the 1979 crash
of Flight 191 in Chicago, which resulted in the grounding
of all DC-10s, culminated with passengers refusing
to fly on the aircraft. Orders for the plane slowed,
and in 1989, the DC-10 went out of production. However, the existing 446 planes
continue to operate around the globe. It is definitely
a safe airplane. In fact, because of these
accidents that it had, it was not only certified once
after the Chicago accident, there was an investigation
of the accident, and there was an investigation
of the design of the airplane, so it was really
certified twice. It had to be the safest airplane
after all it went through, of all time. NARRATOR: Despite this
troubled beginning, the DC-10 ultimately
proved a reliable aircraft, and the safety record improved
as the fleet hours increased. In fact, the DC-10s lifetime
safety record as of 2003 surpassed that of the
venerable Boeing 747. Nevertheless, the remaining
DC-10s operating in the United States, once an icon
of luxury travel, had been relegated
to cargo duty. [music playing] At 12:22 PM on July 19,
1985, two mining dams burst in Stava, Italy. GRAZIANO LUCCHI:
[speaking italian] INTERPRETER: It was impossible
to believe what we saw, how two banks of sand could be
two atomic bombs that caused the total destruction
of the Stava Valley. NARRATOR: The rupture
unleashed a mud and sludge wave more than 100 feet wide. It flowed at a speed
of 55 miles per hour. GIOVANNI TOSATTI: Burst
out, and, of course, considering also the natural
slope of this valley, which is quite steep, it gained
progressive momentum. It reached a very
high acceleration in a matter of seconds. NARRATOR: The mudslide
was over in four minutes, but during that time, 268 people
died, and four hotels and 50 homes were flattened. INTERPRETER: I saw that
everything was swallowed up. There wasn't anything left,
not houses, not anything. NARRATOR: The town of Stava was
virtually wiped off the map. The event has been
called one of the worst industrial catastrophes
in the world. But it could have
been prevented. Stava is located in northeastern
Italy, nestled in a picturesque Alpine Valley. There was primarily
a farming community. Stava has mountains
rich in fluorite, and in 1934, a very productive
mining industry began. In 1967, the first
tailings dam was started. The tailings dam's purpose was
to contain the waste material from the mine. The waste was a mixture
of silt, sand, and water. The sand formed the
dam's structure, and the silt and water were
stored in the basin itself. So their purpose is to store
material at the fluid state, first, that couldn't
be discharged directly into watercourses
because they've got their high pollutant content. NARRATOR: The silt
was supposed to sink to the bottom of the
basin and solidify, while the clear water was
recycled into the streams and rivers of Stava. As more material was poured into
the dam, the size of the basin increased. In just a few years,
the tailings dam rose to 65 feet, twice
the normal height for this kind of structure. In 1969, the mine owners decided
to start another dam right above the first one. GIOVANNI TOSATTI: The choice
couldn't have been worse, because first of all,
we are on a steep slope that these structures can be
considered completely stable only if they are built
in the proper manner, on flat ground, which, of
course, was not the case here. NARRATOR: Another factor
that led to the disaster was the nature of the soil
on which the dams were built. The marshy ground
in Stava was not firm enough to hold the
large earthen structures. GIOVANNI TOSATTI: Just
walking along the slope, you'll see that the
ground is soggy. It gives way. It's always
saturated with water. And you can actually see springs
coming out from the ground. NARRATOR: Over the
next six years, the two tailings dams grew
to more than 165 feet. Local residents became
alarmed, and in 1975, they called upon city authorities
to inspect the dams and determine their stability. GIOVANNI TOSATTI: The thing
was done by an engineer that was appointed by the company
itself that ran the mine. So of course, his
judgment couldn't really be considered objective. This man, when he
saw these structures, he says, it's a miracle that
they haven't already collapsed. NARRATOR: The engineer
suggested that a test be done to determine the
firmness of the soil. The test would have cost
approximately $13,000. GIOVANNI TOSATTI: And
the direction of the mine said, that is too much
money just for this. We'll do it in a
more simple way. That is, getting an iron bar
and pushing it through the soil and test like this manually if
the soil was more or less firm. Of course, a test like
this is ridiculous. NARRATOR: In fact, because of
the marshy nature of the soil, the silt in the basins
had not trained properly, becoming heavier, and
putting more pressure on the outer structure
of the upper basin. On July 19, 1985, the upper
dam suddenly collapsed down into the lower
basin, which burst with an earthshaking force. [ground rumbling] INTERPRETER: So the masses
of sludge crashing down. From there, I went into
a state of mental shock. INTERPRETER: My
house wasn't there. I went just about
out of my mind. My family was made
up of my wife, so dear to me, three
daughters, and four sons. I was left with two
daughters and a son. NARRATOR: Rescue efforts
continued for weeks after the Stava disaster,
but very few victims were found alive. INTERPRETER: You
couldn't go and help anybody, because there was so
much mud, it was like being in a bowl of pudding. If you saw arms, legs,
coming out of it, there was no way for you to get
there to rescue these people. I remember that the
first person I rescued was a child, who I
remember to this day. NARRATOR: In the official
court proceedings, 10 people involved in the
construction, management, and monitoring of
the upper basin were found guilty of causing
the disaster through negligence and incompetence. They were also convicted of
multiple manslaughter charges. Previous owners and engineers
were never arrested. [speaking italian] INTERPRETER: I don't know
what you call it in America, indulgences,
leniency, and they've benefited from such leniency. NARRATOR: The court-imposed
fine, $131 million, well over the $13,000 expense
that might have prevented this disaster 10 years before. So greed, negligence,
superficiality, speculation were
the main aspects of behavior of the people
that caused this disaster. Too many people
thinks business is more important than life. NARRATOR: The Italian parliament
also introduced a new law to make the construction and
maintenance of tailings dams safer. The entire country mourned
the horrifying loss of the people of Stava. Pope John Paul II
paid a moving visit to the memorial site in 1998. In February, 2002, several
of the victims' families established the Stava
1985 Foundation. GRAZIANO LUCCHI:
[speaking italian] INTERPRETER: Essentially, so
that the 268 people who died didn't die in vain. NARRATOR: The town of Stava
is now rebuilt, coming back to life after the disaster. It is a living, growing monument
to those who were sacrificed by its destruction in 1985,
and a lasting reminder of the resilience and spirit
of those who survived. Natural gas is colorless,
odorless, and tasteless. The familiar rotten egg smell we
associate with gas is actually mercaptan. It's added before distribution,
giving natural gas a distinct odor that
serves as a safety device, allowing it to be detected
when a leak occurs. Research to find
an effective odor began as early as the 1920s. However, it took one of the
most heart-wrenching tragedies in American history, the deaths
of over 300 schoolchildren, to necessitate the use
of a malodorous additive. By the early 1930s,
the Great Depression meant economic disaster for
the entire United States. But east Texas fared better. BILL THOMPSON: Dad Joiner
came to east Texas, and he discovered this oil. And of course, that changed-- changed the world of east Texas
and this community forever. This was the bright
spot of the whole United States at that time. NARRATOR: Like many
oil boom towns, New London, Texas, just
130 miles east of Dallas, grew from approximately 850
to several thousand overnight. JOHN DAVIDSON: There
were so many people moving in here with kids that
the little two-room country school was too small. A modern school was built
at a price of $300,000. At the time it was built, it
was one of the richest school districts in the world. NARRATOR: The state
of the art schools sat on a 15-acre campus,
and had 10 oil wells located on its grounds. BILL THOMPSON: That was another
exciting time of my life. Moving from a
three-room school house where we had multiple
grades in one room, moving to a large, two-story
brick school with-- had housed a high school, junior
high, with all the facilities that any school in
the country had. NARRATOR: The school
administration decided to save $300 a
month on heating fuel by using natural gas. At the time, natural gas
was a worthless byproduct of petroleum extraction. Everybody got free gas
from the oil company. They had so much gas that they
had to burn torches at night. NARRATOR: A connection was
made to the company's pipeline, and the free gas
was fed directly into the existing pipelines
in the school's subbasement. But their connection leaked,
and by March 18, 1937, nearly 6,000 cubic
feet of gas had slowly collected in the school's
poorly ventilated subbasement. With no way of detecting
a leak, the school day continued as usual with
a ticking time bomb just under the feet of
London students and teachers. BILL THOMPSON: Everything
was normal until about 3:18 that afternoon. That was the last
period of the day, and my last class
was English class. At the beginning of class,
I asked a girlfriend who sat in front of me
to change seats with me. I wanted to sit behind
the little girl who sat in front of her. She graciously
traded seats with me. NARRATOR: Just minutes before
the school was to be dismissed, the shop teacher
plugged in a sander, and their esteemed
school exploded. I didn't hear anything. Nothing. No sound at all. There must have been a
horrible sound, because I lost the hearing in my right ear. The ceiling fell in, and I
don't know where it came from. Anyhow, that was
all on top of me, and I had my face
down against my desk, and this material was on
top and I couldn't move. And I heard some of the boys
talking, and one of them said, there's somebody under here. And I said, I am. Get me out of here. So they lifted it up
and helped me out. NARRATOR: The impact of
the combustion explosion had lifted the
building into the air and it slammed back
into the ground, entombing students teachers in
its brick, steel, and concrete. BILL THOMPSON: And I
looked at the building, and front of the building
was completely gone. It had blown up and just fell
right back down on the ground flat. NARRATOR: The
devastating explosion was heard nearly 4 miles away. Within 15 minutes, the news
had been relayed over telephone and Western Union lines. Frantic parents
rushed to the school. Residents and oilfield workers
brought in heavy equipment. MOLLIE WARD: People was
just coming from everywhere. They just started
hollering and screaming. People everywhere just
couldn't find their children. They carried them everywhere. They had to start making
makeshift hospitals. NARRATOR: Legions of
volunteers and parents frantically dug
through the night, looking for the young victims. JOHN DAVIDSON: Within 17
hours, it was cleaned up. They cleaned it up so fast that
it hindered the investigation. By time they got people in here
to investigate what happened, there was nothing to look at. NARRATOR: The grief of the
tragedy was widespread. Condolences came from
all over the world, including a telegram
from Eleanor Roosevelt, as well as one from the
chancellor of Germany, Adolph Hitler. BILL THOMPSON: We returned
to school 10 days later, some of us. A lot of us wasn't there. They called roll in
the old gymnasium and gathered by grades,
and there was probably 50% of the normal capacity
of the classes there or less. And that's when I discovered
that the girl I traded seats with was killed. And like I say, that-- I carried that guilt with me. NARRATOR: Of the estimated
650 students and teachers in the building, 319 were dead. JOHN DAVIDSON: There were three
investigating agencies came in, the State Board of Inquiry,
the Bureau of Mines, and Agricultural Department. They all reached
the same conclusion, that no one is to be held
liable for the school explosion. Since natural gas at
that time had no odor, it would not have mattered
how they were getting it or how they were using
it, it would still happen. MOLLIE WARD: Three days
after the explosion, Texas legislature called
a special session in order to pass the odorization
law that we smell gas today for our safety and protection. NARRATOR: The Texas regulation
was quickly adopted worldwide, but tragically,
it took the lives of nearly an entire
generation in one small town to bring about this momentous
leap forward in safety. Since the inception
of the oil tanker, many accidents have
garnered horrific headlines. In the 1990s, there was,
on average, more than one oil tanker spill
every two weeks. But it was the catastrophic
grounding of the Torrey Canyon oil tanker in 1967 that
introduced the world to the devastation
of the super spill. On March 18, 1967,
the Torrey Canyon ran aground off the
southern coast of England. Within two weeks, her
entire cargo of 119,000 tons of crude oil was lost. Close to 200 miles of pristine
coastline were defiled. KERT DAVIES: This was
a really big spill even by modern standards. The tanker spilled three times
the oil that the Exxon Valdez spilled in Alaska, and we know
what damage that spill caused. NARRATOR: Nearly four decades
later, the Terry Canyon accident serves as a valuable
lesson of how poorly designed instruments can be the
catalyst for human error on a grand scale. In 1959, when the Torrey Canyon
was first put into operation, she had a cargo capacity of
60,000 tons of oil, considered small in an era when many ships
had a capacity of over 100,000 tons. KERT DAVIES: In the late
'60s, our dependence on oil, the consumption of oil worldwide
was growing astronomically. Oil was about $0.30
a gallon in the US, and cars got 10
miles to the gallon, so we were using more
and more oil globally. Consequently, the rise
of the supertanker, the transportation
of oil, started to take on new dimensions. NARRATOR: In 1964, as
oil demand increased, the owners of the
Torrey Canyon decided she would be more profitable
with an even larger capacity. In 1965, Torrey
Canyon was brought to the Sasebo shipbuilding
company in Japan for jumboization. Jumboization, in the case
of the Torrey Canyon, as well as many other
tankers, involved cutting it at mid ships,
separating the two halves, and then inserting
a large section in between with
additional cargo tanks. NARRATOR: When the Torrey Canyon
went back to work in 1965, she was the 13th largest
vessel in the world, capable of carrying close
to 122,000 tons of oil. The ship was also equipped
with an autopilot feature. STEVEN CASEY: Well over 90% of
the time on the Torrey Canyon, as well as similar ships
like it at the time, they were on autopilot. And the autopilot system
allowed the helmsman to set a compass heading,
such as 18 degrees, and it would just hold
that compass heading. NARRATOR: Several days
before the fateful collision, the autopilot was set
to 18 degrees north, sending the Torrey Canyon well
clear of the Scilly Isles, a chain of rocky islands
which stood between the ship and her final
destination, a port on the west coast of England. The captain had the ship
running at full speed, 17 knots, in an effort to beat a narrow
tidal window on the evening of March 18, when high tides
would make the port deep enough for the ship to enter. If you missed
it, they would have to wait six days, and the
costs for the crew and the ship and reserving the space on
the harbor are substantial. So he was under considerable
time stress to make this date. NARRATOR: Before he turned in
on what would be his last night afloat, the captain left orders
to be called when the islands were detected on the radar,
signifying their final approach to port. Early the next morning, radar
revealed that strong currents had unexpectedly pushed
the ship to the east. The Torrey Canyon
was aiming right for a precarious channel between
the islands and the coast. When he found that he was not
where he thought he would be, off the Scilly Isles,
his normal course would have been to steer all
the way around to seaward of the isles and come to port. NARRATOR: Going around the
isles would add several hours to the journey, likely
causing the tanker to miss high tide at the port. STEVEN CASEY: The captain
decided that he would basically shoot the gap, about a 6-mile
gap between the Scilly Islands and the Seven Stone Shoals. It was a tricky maneuver,
and not something most any supertanker captain should
seriously consider doing. NARRATOR: But after
entering the channel, the captain realized the
autopilot had the tanker on a collision course
with submerged shoals surrounding the islands. He shifted to manual steering
and spun the wheel to the left, believing he was turning the
ship away from the rocks. The fate of the ship was about
to be sealed by a seemingly minor design flaw. STEVEN CASEY: The captain
and the other officers went back to the chart room,
thinking that they had just avoided a catastrophe, when he
heard the helmsman screaming for him saying that the
ship was not responding. The ship was not responding
because he had accidentally, unintentionally pushed the
control into the control mode which disengaged the helm. The steering wheel
was ineffective. NARRATOR: After
realizing the error, the captain moved the
selector to manual steering. By then, it was far too
late, and the Torrey Canyon ground to a halt over Pollard
Rock, a part of the Seven Stone Shoals, and was
ripped wide open. NARRATOR: The captain's
inability to steer the ship out of harm's way was later
attributed in part to the design of the autopilot
mechanism, which slid easily and without warning from
one gear to the next. STEVEN CASEY: The control
position on the three position lever was similar
to neutral on a car. But unlike a car transmission
system, in which you go, say, from park to drive, and you
have to press a button or input, make a separate action
to make that change, you could just shift this
control to any of these three positions just by
simply moving it, intentionally or
unintentionally. NARRATOR: Within 72
hours of the collision, an estimated 37 million
gallons of the tanker's cargo leaked out. BUD THOMAS: The ship
was gently creaking, and the oil was all
around the ship from the-- wherever she was
ruptured in the hull. NARRATOR: The tanker was so
firmly impaled on the rocks that no tug could pull her off. Efforts to clean up the
massive oil spill were futile. They went at this
from every angle. They hit it with napalm. They tried to burn the oil away. They hit it with explosives
trying to sink it. That didn't work. Then they hit it with tens of
thousands of tons of detergent to try to soak the oil
or disperse the oil, and that didn't help at all. In fact, that proved more
toxic to the ecosystem. There was no precedent
for this type of crash. NARRATOR: Within a few years,
more effective cleanup methods became common practice, but
amazingly, a better autopilot design was not
installed on oil tankers until over 20 years later. You had the same problem that
appears on the Exxon Valdez, with the autopilot engaged,
they turned the wheel, but the vessel did not respond,
because it wasn't supposed to. After Exxon Valdez,
they made a change so that if you turn the
wheel while it is engaged, an alarm sounds. NARRATOR: Navigational
technology on oil tankers has been greatly improved
since the Torrey Canyon. RICK HEPBURN: Nowadays, you
can have alarms if you get off course, audible alarms based
on anything you want as far as the navigational aids. The GPS knows where the ship
is on the surface of the Earth, and the rudder will be
changed to keep the ship on the prescribed track that the
master laid into the computer. NARRATOR: The ever-increasing
number of automated features on modern tankers are
most successful when designed with the user in mind. STEVEN CASEY:
Particularly today, when systems are
becoming so very, very reliable and
well engineered, it is the user interface
and the human factors that play the greatest
role in the success or failure or reliability
of major systems. NARRATOR: Another
lasting consequence of the ecological calamity
was that the accident made the international community
realize the need for stricter penalties for oil polluters. International policies were put
into place to provide relief to the victims, and by 1969,
ship owners became strictly liable for their spills. [music playing]
