December 15 – Disasters in History

Silver Bridge disaster

Todays research got me looking into what happened on this day in history. I wanted to start sharing this information on a regular basis as I look specifically into disasters.

As I write this post, it is 1:10 am on December 15 so let’s take a look at this day in history.

1967, USA, The Silver Bridge Collapse

At around 5 pm, the U.S. Highway 35 bridge connecting Point Pleasant, West Virginia and Kanauga, Ohio suddenly collapsed into the Ohio River. Along with the bridge, thirty one vehicles fell into the river leading to the loss of forty six lives and a further nine people were seriously injured.

Fear struck the nation as the bridge was a major transportation route that connected West Virginia and Ohio.

The bridge was constructed in 1928 and was designed as a two-lane eye-bar suspension type bridge, measuring 2,235 feet in total length, including the approaches.

The bridge got its name as the ‘Silver Bridge‘ because it was the country’s first aluminum painted bridge. It was designed with a twenty-two foot roadway and one five-foot sidewalk and was the first eye-bar suspension bridge of its type to be constructed in the United States.

For thirty nine years the Silver Bridge stood, allowing passage across the Ohio River. With the previous inspections, no one conceived that the structure might fall and collapse into the riverbed. But on December 15, 1967, it only took seconds for the bridge to collapse killing and injuring many individuals.

Rescue crews were on the disaster scene within minutes and were able to save some of the people from drowning in the Ohio River.

After the collapse, many residents questioned why the bridge would suddenly fall into the river below. Two of the reasons that were commonly heard were:

  • A supposed ‘Sonic Boom’ prior to the collapse.
  • Structural failure of a bridge member.

Many people in the West Virginia and Ohio area claim to have heard a ‘Sonic Boom’ around the same time, or just moments before the bridge fell but the theory was later proven false.

After extensive studies of the broken structure members, the cause of failure was determined. The answer was the unique eye-bar design made from the newly innovated heat treated-carbon steel. The old saying, “A chain is only as strong as its weakest link,” turned out to be a fact in the failure of the Silver Bridge.

The heat-treated carbon steel eye-bar broke, placing undue stress on the other members of the bridge. The remaining steel frame buckled and fell due to the newly concentrated stresses.

The fracture was caused from a minute crack formed during the casting of the steel eye-bar. Over the years, stress corrosion and corrosion fatigue allowed the crack to grow, causing the failure of the entire structure.

Another major factor that helped corrosion fatigue and stress corrosion in bringing down the bridge was the weight of new cars and trucks. When the bridge was designed, the design vehicle used was the model-T Ford, which had an approximate weight of less than 1,500 pounds.

In 1967, the average family car weighed 4,000 pounds or more. In 1928, West Virginia law prohibited the operation of any vehicle whose gross weight, including its load, was more than 20,000 pounds. In 1967, the weight limit almost tripled to 60,800 pounds gross, and up to 70,000 with special permits.

1999, Venezuela, Mudslides

Devastating mud slides hit Venezuela in December 1999 over the course of ten days leading to around 190,000 people being evacuated, but sadly, also claiming the lives of between 10,000 and 30,000 people.

Torrential rains inundated the mountainous regions of Venezuela, causing deadly mud slides that devastated the state of Vargas and other areas in the northern part of the country.

It was the coastal regions that were hit the hardest, with a huge 100 km stretch of coastline being wiped out. The heavy rains led to flooding which caused additional damage and misery.

As the magnitude of the crisis intensified on December 15 and 16, the government, headed by Pres. Hugo Chávez, brought in the military to aid in evacuation efforts and to restore order to areas rampant with looters.

The American and Venezuelan Red Cross agencies quickly joined the relief effort and established outposts where victims could receive food and medical care.

Although all members of society were affected, the poorest citizens suffered the greatest losses, as the raging mud and water had obliterated countless flimsy residences and shantytowns.

The disaster highlighted the need for the country to rethink its land-development and environmental policies.

2005, USA, Winter Ice Storms

The December 2005 North American ice storm was a damaging winter storm that produced extensive ice damage in a large portion of the Southern United States from December 14–16. This led to enormous and widespread power outages, and at least 7 deaths.

It was triggered by a deep low pressure system formed over the Gulf of Mexico on 14 December 2005, which began moving northward.

At the same time, cold arctic air from northern Canada penetrated deep into the central United States and lowered the temperatures at the surface while warm air from the Gulf Stream remained at the coast. A second Alberta clipper farther north also added additional energy to the system.

The precipitation remained as rain in the coastal areas, including the large cities from Boston to Washington, D.C.. However, freezing rain was extensive in the inland areas, including around Atlanta, where the temperatures remained just below freezing for extended periods. The freezing rain persisted for many hours, leading to extensive ice damage.

Trees and power lines, along with numerous other lightweight structures, came down in many areas from Georgia northward, and highways (including several Interstate Highways) were closed and impassable.

The heaviest ice accretions were in southwestern North Carolina, where ice over 3/4 inch (20 mm) thick was reported and Charlottesville, Virginia with 1 inch (25,4 mm).

At the higher elevations, and farther north across the Great Lakes region and into northern New England, the storm produced heavy snow with amounts varying between 7 inches to as high as 26 inches (57 cm).

In Canada, 41 centimetres of snow fell in Montreal in about 12 hours, with snowfall rates as high as 30 centimetres in 4 hours, and 11 centimetres in a one-hour period.

In addition, at least seven deaths were blamed on the weather, one of them directly related to weather conditions. One of the deaths was as a result of a tree that fell into a home and crashed into a man in Kannapolis, North Carolina, one as a result of a faulty generator in a house without power, and the other five as a result of traffic accidents.

The ice storm left more than a million people without power in and near the Appalachians, including 630,000 customers in Georgia, 358,000 in South Carolina, 328,000 in North Carolina and 13,000 in Virginia.

It took over a week to restore power. Several emergency shelters also were opened. Electricity was not restored in many places until 20 December 2005, by which time one death was blamed on the outage.

Sources

Corrosion Doctors

Britannica

Wikipedia

   

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