"On This Day" In Engineering History

Today is the 60th anniversary of the Texas City Disaster, the worst industrial accident in American history. On the morning of April 16, 1947, stevedores discovered a fire aboard the Grandchamp, a French cargo ship docked at Texas City, Texas, a petrochemical port on the Gulf of Mexico. The recently-salvaged Liberty ship carried peanuts, tobacco and cotton; drilling equipment, sisal twine, and small ammunition; and 17-million pounds of ammonium nitrate fertilizer. Shortly after 8:00 AM, longshoremen noticed a plume of smoke rising from one of the cargo holds. Sailors doused sacks of fertilizer with two fire extinguishers and a gallon of drinking water, but the fire in Hold 4 continued to grow. As the stevedores lowered a fire hose below deck, the captain of the Grandchamp arrived. Complaining that water would ruin the cargo, the captain ordered his crew to batten the hatches, closed the ventilators, and turn on the steam system.

Within minutes, the heat from the steam caused the ammonium nitrate to break down into water vapor and nitrous oxide, a chemical reaction that produced even more heat and led to thermal runaway. Around 8:30 AM, the growing pressure from the compressed steam in Hold 4 blew off the hatch covers and unleashed a golden column of fire. As sailors and stevedores abandoned their attempts to remove cases of ammunition from Hold 5, the Grandchamp blew its whistle in distress, generating a companion alarm from the Texas City Terminal Railway. By the time that firefighters arrived, the flames from the Grandchamp were hot enough to vaporize water. At 9:12 AM, the ammonium nitrate reached an explosive threshold of 850° F. The subsequent detonation was heard as far as 150 miles away.

The destruction of the Grandchamp hurled 14 million pounds of steel into the sky and created a mushroom cloud that rose more than 2000 feet into the air. The shockwave from the blast sheared the wings off airplanes and broke plate-glass windows as far away as Galveston. According to the Fire Prevention and Engineering Bureau of Dallas, "flying steel fragments" and parts of the Grandchamp's cargo were found up to 13,000 feet away. Drill stems that weighed 2700 pounds buried themselves in the inland soil of Texas City. Falling shrapnel bombarded refineries, piercing pipelines and tearing open tanks of flammable chemicals. Balls of flaming cotton and sisal twine descended from the sky and danced across city streets. At the Monsanto plant, 145 of 450 workers died. Over 1000 businesses and residences were completely destroyed. Later, when some of the smoke cleared, rescuers discovered that the High Flyer, another fertilizer-laden ship at Texas City, was ablaze. Shortly after 1:00 AM on April 17, 1947, the High Flyer exploded in a blast that some observers claimed was even more powerful than that of the Grandchamp.

When dawned arrived, columns of thick, black smoke were visible up to thirty miles away. These dark clouds would hover over Texas City for days to come. Ultimately, the American Red Cross and the Texas Department of Public Safety counted 405 identified and 63 unidentified dead. Another 100 people were classified as missing because their remains were never found. Over 3,500 persons were injured. One-third of the town's 1,519 houses were condemned. Property losses were estimated at $100 million, and did not include the 1.5 million barrels of petroleum products that were destroyed. Although the $20-million Monsanto facility was re-built in less than a year, some of the cargo-handling operations at Texas City never recovered. Today, the Texas City Disaster is remembered quietly, in a grassy cemetery with a marble monument of an angel.

Resources:

http://en.wikipedia.org/wiki/Texas_City_Disaster

http://www.local1259iaff.org/disaster.html

http://www.local1259iaff.org/report.htm