Captain Charles de Guillebon was the master of the French-flagged Liberty ship SS Grandcamp — a war-surplus American cargo vessel transferred to the French shipping company Compagnie Générale Transatlantique in 1946 and operating on the substantial post-war North Atlantic routes between Le Havre and the substantial Gulf of Mexico. He had taken command of the Grandcamp in autumn 1946. He was approximately 50 years old in April 1947.
He died at 9:12 AM on the morning of 16 April 1947 when the Grandcamp detonated alongside Pier O at Texas City, Texas — the largest industrial explosion in American history.
What was in the hold
The Grandcamp had loaded a cargo at Texas City over the preceding several days. The principal cargo was 2,300 tons of ammonium nitrate fertiliser — bagged Texas-manufactured agricultural-grade material, destined for the French agricultural reconstruction programme of 1947. The loading had been completed by approximately the morning of 16 April; the ship was scheduled to depart that afternoon.
Ammonium nitrate is fertiliser under normal storage conditions and is high explosive under specific elevated-temperature conditions. The threshold for detonation is approximately 200 °C with sustained heating. The 1947 American shipping regulations classified the material as non-hazardous bulk cargo and required no specific protective handling protocols.
Fire was discovered in the Grandcamp’s Hold 4 at approximately 8:00 AM on 16 April. The source was never identified — possibly a discarded cigarette, possibly spontaneous heating of moisture-degraded cargo bags, possibly an ignition from the nearby Monsanto styrene-monomer plant — but the fire substantively progressed rapidly through the hold’s bagged cargo over the following hour.
What Guillebon decided
The standard maritime emergency response to a cargo-hold fire is flooding: open the fire mains and the seacocks and allow water to submerge the burning material. Guillebon refused the flooding option. His substantive reasons — as reconstructed from the 1948 congressional inquiry — were substantively two. The first was that flooding the cargo would destroy the commercial value of the 2,300-ton shipment, exposing the Compagnie Générale Transatlantique to liability claims. The second was that the ammonium nitrate cargo was not classified as hazardous and Guillebon did not substantively understand the detonation risk.
He substantively instead deployed steam-injection firefighting: closed the hold hatches and pumped steam into the hold to smother the fire. The substantive technique substantively works well on conventional cargo fires; it substantively fails on ammonium nitrate, because the steam raises the cargo temperature past the detonation threshold.
The detonation
The Grandcamp detonated at 9:12 AM. The substantive explosion was equivalent to approximately 2.7 kilotons of TNT — about a fifth of the Hiroshima atomic-bomb yield. The blast destroyed approximately one square mile of the Texas City harbour front, including the entire Monsanto chemical plant on the adjacent pier, the Texas City fire department’s entire on-scene apparatus (the fire crews had boarded the Grandcamp through the morning to assist with the fire), and portions of the city’s residential west side.
Approximately 581 people died in the initial blast and in the subsequent secondary fires. Captain Guillebon and the entire Grandcamp crew were among the dead. The nearby Liberty ship SS High Flyer — carrying a similar ammonium-nitrate cargo — caught fire from the blast and detonated 16 hours later at 1:10 AM on 17 April, extending the death toll.
The Texas City disaster remains the largest industrial accident in American history. The 1948 congressional inquiry identified the captain’s steam-injection decision as the proximate cause and recommended significant regulatory reforms to the maritime transport of ammonium nitrate.