The engineering world has seen some great achievements. However, history has shown that engineering has also faced many terrible failures. Manufacturers, workers, and engineers carry huge responsibilities on their shoulders. A slight miscalculation or a lack of communication has led to some of the worst catastrophes ever. These disasters claimed the lives of many workers and innocent people, not to mention the huge economic loss that followed.

Here, you can gain some insight into such disasters through our chronologically-ordered list of the 14 worst engineering disasters of all time.

1 The SS Sultana steamboat explosion near Memphis, Tennessee in 1865 is the worst maritime disaster in the US history, but it did not get a lot of media coverage that time. People hardly remember this disaster today.

The SS Sultana was a steamboat engineered in Cincinnati and usually sailed on the Mississippi and Ohio rivers. The steamboat was state-of-the-art, boasting the most advanced safety equipment for those times.

On 27th April 1865, the steamboat carried approximately 2,300 passengers including released Union prisoners of war, civilians, and the crew. Three of Sultana’s four boilers exploded at around 2 a.m., and the steamboat sank around seven miles from Memphis, Tennessee. The death toll was estimated to have been between 1,500-1,800 passengers.

After the investigation, the conclusion was reached that the water levels in the boiler caused this disaster. The crew had overloaded the steamboat (Sultana’s carrying capacity was 376) which made the situation worse. Furthermore, the investigation cited that one of the four boilers had been leaking a few days prior to the mishap, and its repair was dubious. The combined effects of these factors led to the unfortunate catastrophe.(source)

2 The Johnstown Flood in Pennsylvania, 1889. Heavy rains and failure of a neglected dam led to the disaster which caused 2,209 reported deaths, and nearly wiped off the city of Johnstown.

Johnstown was a prosperous town in central Pennsylvania, USA. It was known for its steel production.

The South Fork dam was a poorly maintained dam and hardly strong enough to handle the tremendous pressure from Lake Conemaugh. However, heavy downpours combined with the lake’s pressure led to the catastrophic failure of the dam and a terrible flood ensued. 2,209 people reportedly died in the “Great Flood of 1889.” Moreover, the estimated property damage was around $17 million, a huge sum at that time.

The American Red Cross led the relief effort and they collected around $3.7 million from donations. The flood is a prime example of an engineering failure and poor maintenance.(source)

3 The Quebec Bridge collapse in Canada was the largest ever cantilever bridge in the world. It collapsed twice, once in 1907 and again in 1916. The disaster killed a reported 88-89 workers.

The Quebec Bridge with its span of 1,801 feet, is still the world’s largest ever cantilever bridge. In fact, the bridge still has its name in the National Historic Site of Canada.

The bridge collapsed the first time on 29th August 1907. During the collapse, the workers were working on the cantilever arm. Fifty-five people reportedly died by either drowning or the falling debris.

The board of engineers felt they had learned from their mistakes and decided to rebuild the bridge with the lower chords of the cantilevers arms several times stronger than before.  Yet again, on the 11th September 1916, the bridge’s central span crumbled killing 13 workers.

The total damage cost of the two disasters was estimated to be $22 million. The incident showed humanity the disastrous effects of engineering failures and improper supervision.(source)

4 The sinking of RMS Titanic in 1912 is a famous catastrophe. The grand British passenger liner sank into the North Atlantic Ocean after hitting an iceberg. It is reported that 1,514 passengers died. The accident incurred an estimated economic loss of $7.5 million.

The world had declared RMS Titanic a legend even before its maiden voyage. When the ship set sail from Southampton to New York, the crew was so assured about Titanic’s safety that they carried only 20 lifeboats. This was barely enough for half of the 2,200 passengers.

Four days after the voyage began, the ship struck an iceberg at 11:40 p.m on 14 April 1912. The collision proved deadly as the icy waters of the North Atlantic Ocean soon filled the ship. The death toll was 1,514 passengers.  Later on, the liner Carpathia rescued 705 survivors.

According to the builders, Titanic should have stayed afloat for at least two more days despite the collision. After several investigations, conclusions came out that the grand liner had several design flaws and material failures. The collision with iceberg caused a fracture of the brittle hull steel and the wrought iron rivets. The fracture was immediate and it was a result of a combination of three factors: low temperature, high impact loading, and high sulfur content in the hull steel.(1,2)

5 The Hindenburg airship disaster in 1937 during a docking attempt in New Jersey, USA caused  36 fatalities, and the catastrophe marked the end of airship travel.

The German LZ-129 Hindenburg was the biggest commercial airship ever built. Moreover, at that time, it was technologically the most advanced airship. Its size was three times that of a Boeing 747, and it was capable of a top speed of 84 mph.

The mishap occurred on 6 May 1937. The Hindenburg was carrying 97 passengers when it exploded filling the sky over New Jersey with fiery smoke. The gigantic airship fell to the ground on its tail and burned to ashes within a minute. Sixty-two passengers leaped over dozens of feet to their safety and managed to survive.

The cause of the accident was a hydrogen gas leak from the fuel cells which combined with oxygen to form a highly flammable mixture. This mixture ignited and spawned a massive fire. It was the first engineering mishap caught on film, and it shattered the public’s confidence in airships.(source)

6 The Tacoma Bridge collapse of 1940 in Washington, USA was a calamity of the world’s third longest suspension bridge back then and had a crucial impact on engineering. It caused the governing of the modeling of all the long-span bridges in the future.

The Tacoma Narrows Bridge was an iconic, long-span bridge built in the state of Washington in the USA in the 1930s.  It was opened to traffic on t July 1940. Leon Moisseiff planned the building’s design to be far more flexible than the acceptable standard ratios.

On 7 November 1940,  strong winds of 40 mph battered the area and the bridge oscillated significantly. The bridge towers were made of strong, structural carbon steel, yet they proved no match for the violent movements which eventually caused the bridge to collapse. Fortunately, there were no fatalities except for a dog. The estimated loss from the mishap was $6.4 million.

The disaster is now presented in popular physics textbooks as an illustration of elementary forced-resonance.  The high-velocity winds caused aero-elastic flutter at a frequency equaling the bridge’s natural frequency. Furthermore, the bridge was vulnerable to wind-generated vibrations, and the investigations proved that the collapse was inevitable.(source)

7 The failure of the Banqiao Dam in China in 1975, now a forgotten legacy, is arguably the worst engineering disaster of all time. Estimates tell that an unprecedented 171,000 to 230,000 people died in the calamity while 11 million more people had to relocate.

The Banqiao Dam was built on the river of Ru in June 1952. The design of the dam gave it the name “iron dam” as it was considered unbreakable. However, Chen Xing, a prominent hydrologist of the country warned that the overbuilding of dams and reservoirs could increase the water table beyond safe levels and cause a disaster. The government removed Chen from the project.

Chen’s warnings turned out to be true when in August 1975, Henan Province’s Banqiao Dam toppled. The flooding killed an estimated 171,000 to 230,000 people and forced 11 million people to displace. Moreover, the disaster caused a staggering economic loss of approximately $1.6 billion.

This disaster was a culmination of many factors including unsafe construction, poor design and maintenance, overbuilding of dams in the region, and the typhoon Nina which precipitated the disaster.(source)