Modern Marvels - Engineering Disasters 2 1/5

Watch the rest of the parts here.

9/11 Debunked: "Molten Metal" Explained

9/11 CONSPIRACY: NIST CHIEF ENGINEER LIES ABOUT MOLTEN METAL

A Weird Phenomena in Engineering History

Tower of Pisa - Pisa, Italy 

The leaning Tower of Pisa is famous because it leans. Although it was designed to be perfectly vertical, it started to lean during construction. However, even without this famous characteristic, this building would still be one of the most remarkable architectural structures from medieval Europe. It stands at 60 metres and until 1990 was leaning at about a 10 degree angle. See more facts about Leaning Tower of Pisa. Tower of Pisa is more accurately referred to simply as the bell tower, or campanile. The Pisa tower is one of the four buildings that make up the cathedral complex in Pisa, Italy, called Campo dei Miracoli or Piazza dei Miracoli, which means Field of Miracles.

The first building constructed at Campo dei Miracoli, Pisa, was the cathedral, or Duomo di Pisa, which rests on a white marble pavement and is an impressive example of Romanesque architecture. The next building added was the baptistery just west of the dome. Then work on the campanile began. Before the work on the campanile was completed the cemetery, Campo Santo, was built.

Piazza dei Miracoli of Pisa is the most splendiferous assemblage of Romanesque architecture in Italy. Faced in gray-and-white striped marble and bristling with columns and arches, the cathedral, with its curiously Islamic dome and matching domed baptistery, rises from an emerald green lawn. Flanking one side of the piazza, the camposanto, or cemetery, is a gracefully elongated cloister enclosing a burial ground with earth reputedly brought back during the Crusades from Golgotha, the hill where Jesus was crucified, so that noble Pisans could rest in holy ground.

Leaning Tower of Pisa

The Leaning Tower of Pisa is the piazza's crowning glory. Although only a third as high as the Washington Monument, it was a miracle of medieval engineering, probably the tallest bell towers in Europe. With 207 columns ranged around eight stories, Tower of Pisa looks like a massive wedding cake knocked precariously askew by a clumsy giant guest.The construction of Tower of Pisa began in August 1173 and continued for about 200 years due to the onset of a series of wars. Till today, the name of the architect is a mystery.

The leaning Tower of Pisa was designed as a circular bell tower that would stand 185 feet high. It is constructed of white marble. The tower has eight stories, including the chamber for the bells. The bottom story consists of 15 marble arches. Each of the next six stories contains 30 arches that surround the tower. The final story is the bell chamber itself, which has 16 arches. There is a 297 step spiral staircase inside the tower leading to the top.

The top of the leaning tower of Pisa is about 17 feet off the vertical. The tower is also slightly curved from the attempts by various architects to keep it from leaning more or falling over.

Many ideas have been suggested to straighten the Tower of Pisa, including taking it apart stone by stone and rebuilding it at a different location. In the 1920s the foundations of the tower were injected with cement grouting that has stabilized the tower to some extent.

Until recent years tourists were not allowed to climb the staircase inside the tower, due to consolidation work. But now the leaning Tower of Pisa is open again and it is one of the most popular tourist attractions in Italy.

Galloping Gertie

Structural Deffects

Social Implication: Sad insight into Engineering Failures

Engineering failures are subsequently contributed from day one when a young engineer is still at university. His attitudes of just trying to memorize the content of the particular subject and pass his or he exams and not fully understanding concepts can have fatal ramifications and incur innumerable casualties. It all starts from the day you study to become an engineer later on. I now realize this sad yet true concept.

- By A 1st year Civil Engineering Student -

email me for questions on: colinavosa@yahoo.com

Civil Engineering Disasters – Collapse Of Bridges

September 11, 1916. Quebec Bridge (Canada)

This is not the first destruction of the bridge. The first time tragedy occurred in 1907.
About first collapse of the bridge
The bridge was nearing completion, when the local engineering began noticing increasing distortions of key structural members already in place. After four years of construction, the south arm and part of the central section of the bridge collapsed into the St. Lawrence River in just 15 seconds. Of the 86 workers on the bridge that day near quitting time, 75 were killed and the rest were injured.
About second collapse of the bridge After a Royal Commission of Inquiry into the collapse, construction started on a second bridge, but September 11, 1916, when the central span was being raised into position, it fell into the river, killing 13 workers.

December 15, 1967. Silver Bridge (USA)
On December 15, 1967, the Silver Bridge collapsed while it was choked with rush hour traffic, resulting in the deaths of 46 people. Investigation of the wreckage pointed to the cause of the collapse being the failure of a single eye-bar in a suspension chain, due to a small defect only 0.1 inches (2.54 mm) deep. It was also noted that the bridge was carrying much heavier loads than it was originally designed for and was poorly maintained.The new bridge that replaced the Silver Bridge was named the Silver Memorial Bridge.

March 17, 1945. Ludendorff Bridge (Remagen, Germany)
28 U.S. army engineers were killed while working to strengthen the bridge, and 93 others were wounded.

May 9, 1980. Sunshine Skyway Bridge (Florida, USA)
The Sunshine Skyway Bridge was collapsed on May 9, 1980, when the freighter SS Summit Venture collided with a pier (support column) during a storm , sending over 1200 feet of the bridge plummeting into Tampa Bay. The collision caused six automobiles and a bus to fall 150 feet, killing 35 people.

June 28, 1983. Mianus River Bridge (Connecticut, USA)
Three people were killed when their vehicles fell with the bridge into the Mianus River 70 feet below, and three were seriously injured. Collapse due to failure of the Pin and Hanger assembly supporting the span.

October 21, 1994. Seongsu Bridge (Seoul, South Korea)
On October 21, 1994, Seongsu Bridge connecting Seongsu-dong and Apgujeong-dong of Gangnam-gu, Seoul, collapsed. The slab (48 m) between the fifth and the sixth leg of the Bridge collapsed so 32 people died and 17 people were injured. One of its concrete slabs fell due to a failure of the suspension structure. This structural failure was caused by joints of trusses (steel structures) supporting the bridge slab were not welded to the full; the welding thickness, which should be over 10mm, was only 8mm; and further, connecting pins for steel bolts were poor.

January 4, 1999. Rainbow bridge (China)
In January 4, 1999, a pedestrian Rainbow bridge across the Qi River in the Sichuan province collapsed three years after it was built. The collapse of the Rainbow bridge led to 40 deaths and 14 injuries. Parts of the bridge were rusty, concrete used in its construction was too weak and there were serious welding problems.

March 4 , 2001. Hintze Ribeiro Bridge (Castelo de Paiva, Portugal)
On March 4, 2001, the Hintze Ribeiro Bridge, made of steel and concrete, collapsed in Entre-os-Rios, Castelo de Paiva, Portugal, killing to 70 people, including those in a bus and three cars that were attempting to get to the other side of the river.

August 28, 2003. Bridge Daman (Daman, India)
At least 25 people, including 23 children, die when a bridge in the western coastal area of Daman collapsed into a muddy river, throwing a school bus, 10 vehicles and pedestrians into the swirling waters due to heavy rains.

November 7, 2005. (Almunecar, Spain)
Five Portuguese and one Spanish national died near Almunecar on Spain’s, after a 20-ton section of motorway viaduct fell from 80 meters onto workers below.

December 2, 2006. (Bihar, India)
Thirty-three people are killed when a 150-year-old bridge, being dismantled, crashed on the train near the Bhagalpur railway station in the state of Bihar.

August 1, 2007. Minneapolis I-35W bridge (Minneapolis, USA)
On August 1, 2007, during the evening rush hour, the main spans of the bridge collapsed, falling into the river and onto its banks. Thirteen people died and approximately one hundred more were injured. The 1,907-foot bridge fell into the Mississippi River. Currently under investigation.

August 13, 2007. Tuo River bridge (Hunan, China)
The 140-foot-high bridge spanning the Tuo River in the central Hunan city of Fenghuang collapsed as workers removed scaffolding from its facade. Investigation underway.

In case we missed some please feel free to write about it in the comment box and we will update it as soon as possible

The World's Weirdest Engineering Disaster at Oddorama

Meanwhile, up on the surface, the tremendous sucking power of the whirlpool was causing violent destruction. It swallowed another nearby drilling platform whole, as well as a barge loading dock, 70 acres of soil from Jefferson Island, trucks, trees, structures, and a parking lot. The sucking force was so strong that it reversed the flow of a 12-mile-long canal which led out to the Gulf of Mexico, and dragged 11 barges from that canal into the swirling vortex, where they disappeared into the flooded mines below. It also overtook a manned tug on the canal, which struggled against the current for as long as possible before the crew had to leap off onto the canal bank and watch as the lake consumed their boat.

Early in the morning on November 21, 1980, twelve men decided to abandon their oil drilling rig on the suspicion that it was beginning to collapse beneath them. They had been probing for oil under the floor of Lake Peigneur when their drill suddenly seized up at about 1,230 feet below the muddy surface, and they were unable free it. In their attempts to work the drill loose, which is normally fairly easy at that shallow depth, the men heard a series of loud pops, just before the rig tilted precariously towards the water.

At the time, Lake Peigneur was an unremarkable body of water near New Iberia, Louisiana. Though the freshwater lake covered 1,300 acres of land, it was only eleven feet deep. A small island there was home to a beautiful botanical park, oil wells dotted the landscape, and far beneath the lake were miles of tunnels for the Diamond Crystal salt mine.

Concluding that something had gone terribly wrong, the men on the rig cut the attached barges loose, scrambled off the rig, and moved to the shore about 300 yards away. Shortly after they abandoned the $5 million Texaco drilling platform, the crew watched in amazement as the huge platform and derrick overturned, and disappeared into a lake that was supposed to be shallow. Soon the water around that position began to turn. It was slow at first, but it steadily accelerated until it became a fast-moving whirlpool a quarter of a mile in diameter, with its center directly over the drill site.

As the whirlpool was forming on the surface, Junius Gaddison, an electrician working in the salt mines below, heard a loud, strange noise coming down the corridor. Soon he discovered the sound’s source, which was rushing downhill towards him: fuel drums banging together as they were carried along the shaft by a knee-deep stream of muddy water. He quickly called in the alarm, and the mine’s lights were flashed three times to signal its immediate evacuation. Many of the 50 miners working that morning, most as deep as 1,500 feet below the surface, saw the evacuation signal and began to run for the 1,300 foot level, where they could catch an elevator to the surface. However, when they reached the third level, they were blocked by deep water.

Clearly, the salt dome which contained the mine had been penetrated by the drill crew on the lake. Texaco, who had ordered the oil probe, was aware of the salt mine’s presence and had planned accordingly; but somewhere a miscalculation had been made, which placed the drill site directly above one of the salt mine’s 80-foot-high, 50-foot-wide upper shafts. As the freshwater poured in through the original 14-inch-wide hole, it quickly dissolved the salt away, making the hole grow bigger by the second. The water pouring into the mine also dissolved the huge salt pillars which supported the ceilings, and the shafts began to collapse.

As most of the miners headed for the surface, a maintenance foreman named Randy LaSalle drove around to the remote areas of the mine which hadn’t seen the evacuation signal, and warned the miners there to evacuate. The miners whose escape was slowed by water on the third level used mine carts and diesel powered vehicles to make their way up to the 1,300 foot level, where they each waited their turn to ride the slow, 8-person elevator to the surface as the mine below them filled with water. Although it seemed to take forever to get out, all 50 miners managed to escape with their lives.

After three hours, the lake was drained of its 3.5 billion gallons of water. The water from the canal, now flowing in from the Gulf of Mexico, formed a 150-foot waterfall into the crater where the lake had been, filling it with salty ocean water. As the canal refilled the crater over the next two days, nine of the sunken barges popped back to the surface like corks, though the drilling rigs and tug were left entombed in the ruined salt mine.

Despite the enormous destruction of property, no human life was lost in this disaster, nor were there any serious injuries. Within two days, what had previously been an eleven-foot-deep freshwater body was replaced with a 1,300-foot-deep saltwater lake. The lake’s biology was changed drastically, and it became home to many species of plants and fish which had not been there previously.

Of course numerous lawsuits were filed, and they were subsequently settled out-of-court for many millions of dollars. The owners of the Crystal Diamond salt mine received a combined $45 million in damages from Texaco and the oil drilling company, and got out of the salt mining business for good.

No official blame for the miscalculation was ever decided, because all of the evidence was sucked down the drain, but the story described here is the generally accepted theory of what caused this massive disaster.

Worst Tragedy in America after JFK's death

The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida, United States, at 11:39 a.m. EST (16:39 UTC).

Disintegration of the entire vehicle began after an O-ring seal in its right solid rocket booster (SRB) failed at liftoff. The O-ring failure caused a breach in the SRB joint it sealed, allowing pressurized hot gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB attachment hardware and external fuel tank. This led to the separation of the right-hand SRB's aft attachment and the structural failure of the external tank. Aerodynamic forces promptly broke up the orbiter.

The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation. Although the exact timing of the death of the crew is unknown, several crew members are known to have survived the initial breakup of the spacecraft. However, the shuttle had no escape system and the astronauts did not survive the impact of the crew compartment with the ocean surface.

The disaster resulted in a 32-month hiatus in the shuttle program and the formation of the Rogers Commission, a special commission appointed by United States President Ronald Reagan to investigate the accident. The Rogers Commission found that NASA's organizational culture and decision-making processes had been a key contributing factor to the accident. NASA managers had known that contractor Morton Thiokol's design of the SRBs contained a potentially catastrophic flaw in the O-rings since 1977, but they failed to address it properly. They also disregarded warnings from engineers about the dangers of launching posed by the low temperatures of that morning and had failed to adequately report these technical concerns to their superiors. The Rogers Commission offered NASA nine recommendations that were to be implemented before shuttle flights resumed.

Many viewed the launch live due to the presence on the crew of Christa McAuliffe, the first member of the Teacher in Space Project. Media coverage of the accident was extensive: one study reported that 85 percent of Americans surveyed had heard the news within an hour of the accident. The Challenger disaster has been used as a case study in many discussions of engineering safety and workplace ethics.

The shuttle was designed to withstand a load factor of 3 (or 3 g), with another 1.5 g safety factor built in. The crew cabin in particular is a very robust section of the shuttle because of its design and construction of reinforced aluminum. During vehicle breakup, the crew cabin detached in one piece and slowly tumbled into a ballistic arc. NASA estimated the load factor at separation to be between 12 and 20 g; however, within two seconds it had already dropped to below 4 g and within ten seconds the cabin was in free fall. The forces involved at this stage were likely insufficient to cause major injury.

Astronauts from a later Shuttle flight (STS-34) stand next to their PEAPs

At least some of the astronauts were likely alive and briefly conscious after the breakup, as three of the four Personal Egress Air Packs (PEAPs) on the flight deck were found to have been activated. Investigators found their remaining unused air supply roughly consistent with the expected consumption during the 2 minute 45 second post-breakup trajectory.

While analyzing the wreckage, investigators discovered that several electrical system switches on Pilot Mike Smith's right-hand panel had been moved from their usual launch positions. These switches were protected with lever locks that required them to be pulled outward against a spring force before they could be moved to a new position. Later tests established that neither force of the explosion nor the impact with the ocean could have moved them, indicating that Smith made the switch changes, presumably in a futile attempt to restore electrical power to the cockpit after the crew cabin detached from the rest of the orbiter.

Whether the astronauts remained conscious long after the breakup is unknown, and largely depends on whether the detached crew cabin maintained pressure integrity. If it did not, the time of useful consciousness at that altitude is just a few seconds; the PEAPs supplied only unpressurized air, and hence would not have helped the crew to retain consciousness. The cabin hit the ocean surface at roughly 207 mph (333 km/h), with an estimated deceleration at impact of well over 200 g, far beyond the structural limits of the crew compartment or crew survivability levels.

“Scob fought for any and every edge to survive. He flew that ship without wings all the way down....they were alive”
- Robert Overmyer, NASA Lead Investigator -

On July 28, 1986, Rear Admiral Richard H. Truly, NASA's Associate Administrator for Space Flight and a former astronaut, released a report from Joseph P. Kerwin, biomedical specialist from the Johnson Space Center in Houston, relating to the deaths of the astronauts in the accident. Dr. Kerwin, a veteran of the Skylab 2 mission, had been commissioned to undertake the study soon after the accident. According to the Kerwin Report:

The findings are inconclusive. The impact of the crew compartment with the ocean surface was so violent that evidence of damage occurring in the seconds which followed the disintegration was masked. Our final conclusions are:

• the cause of death of the Challenger astronauts cannot be positively determined;
• the forces to which the crew were exposed during Orbiter breakup were probably not sufficient to cause death or serious injury; and
• the crew possibly, but not certainly, lost consciousness in the seconds following Orbiter breakup due to in-flight loss of crew module pressure.

Despite the report, some experts, including one of NASA's lead investigators Robert Overmyer, believed most if not all of the crew were alive and possibly conscious during the entire descent until impact with the ocean.

Primary Causes of Engineering Disasters

The primary causes of engineering disasters are usually considered to be

• human factors (including both 'ethical' failure and accidents)
• design flaws (many of which are also the result of unethical practices)
• materials failures
• extreme conditions or environments, and, most commonly and importantly
• combinations of these reasons
  
  

A recent study conducted at the Swiss federal Institute of technology in Zurich analyzed 800 cases of structural failure in which 504 people were killed, 592 people injured, and millions of dollars of damage incurred. When engineers were at fault, the researchers classified the causes of failure as follows:

Insufficient knowledge ....................................... 36% Underestimation of influence .............................. 16% Ignorence, carelessness, negligence .................... 14% Forgetfulness, error ........................................... 13% Relying upon others without sufficient control ....... 9% Objectively unknown situation ............................. 7% Unprecise definition of responsibilities .................. 1% Choice of bad quality .......................................... 1% Other ................................................................. 3%