Texas City Disaster April 1947 - Grandcamp #maritimehistory

Grandcamp – On 16 April 1947, the French-registered Liberty ship caught fire and exploded dockside while being loaded with ammonium nitrate at Texas City, Texas. In what came to be called the Texas City Disaster an estimated 581 people, including all of the ship's crew and 28 firefighters, were lost and about 5,000 injured.

On April 16, 1947, around 8:00 a.m. smoke was spotted in the cargo hold of the Grandcamp while she was still moored. Over the next hour, attempts to extinguish the fire or bring it under control failed as a red glow returned after each effort to douse the fire.

Image; A group of firefighters on the dock move firehoses into position to fight a fire on board the Grandcamp cargo ship before the explosions.

Shortly before 9:00 a.m., the captain ordered his men to steam the hold, a firefighting method where steam is piped in to extinguish fires, to preserve the cargo. This was unlikely to be effective, as ammonium nitrate produces its own oxygen, thus neutralizing the extinguishing properties of steam. The steam may have contributed to the fire by converting the ammonium nitrate to nitrous oxide[dubious – discuss], while augmenting the already intense heat in the ship's hold.

The fire attracted spectators along the shoreline, who believed they were at a safe distance.

Eventually, the steam pressure inside the ship blew the hatches open, and yellow-orange smoke billowed out. This color is typical for nitrogen dioxide fumes. The unusual color of the smoke attracted more spectators. Spectators also noted that the water around the docked ship was boiling from the heat, and the splashing water touching the hull was being vaporized into steam. The cargo hold and deck began to bulge as the pressure of the steam increased inside.

At 9:12 a.m., the ammonium nitrate reached an explosive threshold from the combination of heat and pressure. The vessel then detonated, causing great destruction and damage throughout the port. The tremendous blast sent a 15-foot (4.5 m) wave that was detectable nearly 100 miles (160 km) off the Texas shoreline. The blast leveled nearly 1,000 buildings on land.

The Grandcamp explosion destroyed the Monsanto Chemical Company plant and resulted in ignition of refineries and chemical tanks on the waterfront. Falling bales of burning twine from the ship's cargo added to the damage while the Grandcamp's anchor was hurled across the city. Two sightseeing airplanes flying nearby had their wings shorn off, forcing them out of the sky.

10 miles (16 km) away, people in Galveston were forced to their knees. People felt the shock 250 miles (400 km) away in Louisiana. The explosion blew almost 6,350 short tons (5,760 metric tons) of the ship's steel into the air, some at supersonic speed. Official casualty estimates came to a total of 567, including all the crewmen who remained aboard the Grandcamp. All but one member of the 28-man Texas City volunteer fire department were killed in the initial explosion on the docks while fighting the shipboard fire. With fires raging throughout Texas City, first responders from other areas were initially unable to reach the site of the disaster.

The first explosion ignited ammonium nitrate in the nearby cargo ship High Flyer. The crews spent hours attempting to cut the High Flyer free from her anchor and other obstacles, without success. After smoke had been pouring from the hold for over five hours, and about 15 hours after the explosions aboard the Grandcamp, the High Flyer exploded, demolishing the nearby SS Wilson B. Keene, killing at least two more and increasing the damage to the port and other ships with more shrapnel and burning material. One of the propellers on the High Flyer was blown off, and subsequently found nearly a mile inland. It is now part of a memorial park, and sits near the anchor of the Grandcamp. The propeller is cracked in several places, and one blade has a large piece missing.

Image: Wreckage of the Wilson B. Keene. The large piece of wreckage in the foreground may be from the Grandcamp.

The cause of the initial fire on board the Grandcamp was never determined, but it may have been started by a cigarette discarded the previous day, meaning the ship's cargo had been smouldering throughout the night when it was discovered on the morning of the day of the explosion.

Wikipedia