22 avril 2009

Grandcamp, Vu de la mer



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On a mis les pieds dans l'eau pour cette photo, avec la mer qui montait inexorablement et nous repoussait vers le rivage.
Sur la gauche, l'épi de bois visble sur la photo pécédente et d'où a été prise celle d'avant çà.
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On a raconté l'histoire du cargo LE GRANDCAMP et son explosion apocalyptique dans le port de Texas City le 16 Avril 1947 (le début ici et la suite ). Voilà maintenant la fin de la tragédie.

Ce jour-là, le 16 Avril 1947, un autre cargo, le S.S. High Flyer, est amarré à coté du GRANDCAMP. Il contient une cargaison de soufre et plus de mille tonnes de nitrate d'ammonium. La force de l'explosion du GRANDCAMP brise ses amarres et il part à la dérive, se logeant finalement contre un autre Liberty Ship, le Wilson B. Keene. Le High Flyer est sévèrement endommagé, mais son équipage reste à bord jusqu'à ce que la fumée et les vapeurs de soufre les forcent à abandonner le navire. Dans l'aprés-midi, une équipe de sauveteurs monte à bord, à la recherche de victimes. Ils aperçoivent des flammes au fond de la cale et alertent les pompiers. Mais ceux-ci sont débordés, et plusieurs heures passent avant que des remorqueurs arrivent de Galveston pour pousser le High Flyer loin des quais.

A 1 heure du matin, le lendemain 17 Avril, les flammes éruptent de la cale du High Flyer, et les remorqueurs s'éloignent aussi vite que possible. Dix minutes plus tard, le cargo explose, une explosion que les témoins estiment encore plus forte que celle du GRANDCAMP. Il y a pourtant peu de victimes, il fait nuit, et le port est oomplètement évacué. Un véritable feu d'artifices de morceaux d'acier incandescent illumine le ciel et retombe sur la ville. De nouveau, de nombreux foyers d'incendie redémarrent. De nouveaux réservoirs de pétrole sont touchés et explosent.
Quand le jour se lève, les colonnes de fumée sont visibles à 50 kms. Ces nuages vont couvrir le Texas pendant de nombreux jours, jusqu'à ce que tous les incendies soient éteints.

L'explosion du Grandcamp reste la plus grande catastrophe industrielle dans l'histoire des Etats-Unis. L'explosion fut si intense, les incendies si nombreux, qu'un bilan exact fut impossible. La Croix Rouge et l'Eat du Texas comptèrent 405 morts identifiés et 63 non-identifiés. Une centaines de victimes sont "présumées mortes", aucune trace de leur corps n'ayant été retrouvée. Le nombre de blessés fut estimé à 3.500, soit un quart de la population de Texas City. Les dégâts matériels s'élèvent à $100 million (en dollars de 1947), sans tenir compte des 1,5 millions de barils de pétrole partis en flammes. Les raffineries, les pipelines, 50 réservoirs sont détruits ou sévèrement endommagés. Un tiers des habitations de Texas City a disparu, laissant plus de 2.000 sans-abris.

Que fut la cause de l'explosion? La vapeur.
Elle liquéfie le nitrate d'ammonium en oxide d'azote, très volatile. Et le nitrate d'ammonium a pu fournir assez d'oxygène pour nourrir l'incendie, rendant la vapeur incapable de combattre les flammes. La chaleur de la vapeur augmenta la température de la cargaison, jusqu'à 450 degrés, température à laquelle le nitrate d'ammonium explose. Le mazout, stocké dans les cales 3 et 4, a sans doute aussi infiltré les sacs d'engrais, mettant encore, littéralement, de l'essence sur le feu.

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We put our feet in the water for this photograph, the rising tide pushing us to the shore. On the left, the old pier visible on the previous picture and from where this one was taken.
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In the previous posts (Part 1 here and part 2 here), We started the history of the freighter GRANDCAMP and its horrendous explosion in the port of Texas City on April 16, 1947. Now it's time for the dramatic conclusion.

Next to the GRANDCAMP was another freighter, the S.S. High Flyer. It was loaded with sulfur as well as a thousand tons of ammonium nitrate fertilizer. The force of the Grandcamp's explosion had torn the High Flyer from its moorings and caused it to drift across the slip, where it lodged against another Liberty Ship, the Wilson B. Keene. The High Flyer was severely damaged, but many of its crew members, although injured, remained on board for about an hour until the thick, oily smoke and sulfur fumes drifting across the waterfront forced the master to abandon ship. Much later in the afternoon, two men looking for casualties boarded the High Flyer and noticed flames coming from one of the holds. Although they reported this to someone at the waterfront, several more hours passed before tugs manned by volunteers arrive from Galveston to pull the burning ship away from the docks.

By 1:00 A.M. on 17th April, flames were shooting out of the hold. The tugs moved quickly out of the slip. Ten minutes later, the High Flyer exploded in a blast witnesses thought even more powerful than that of the GRANDCAMP. Although casualties were light because rescue personnel had evacuated the dock area, the blast compounded already severe property damage. In what witnesses described as something resembling a fireworks display, incandescent chunks of steel which had been the ship arched high into the night sky and fell over a wide radius, starting numerous fires. Crude oil tanks burst into flames, and a chain reaction spread fires to other structures previously spared damage. When dawn arrived, large columns of thick, black smoke were visible thirty miles away. These clouds hovered over Texas City for days until the fires gradually burned out or were extinguished by weary fire-fighting crews.

The Grandcamp's explosion triggered the worst industrial disaster, resulting in the largest number of casualties, in American history. Such was the intensity of the blasts and the ensuing confusion that no one was able to establish precisely the number of dead and injured. Ultimately, the Red Cross and the Texas Department of Public Safety counted 405 identified and 63 unidentified dead. Another 100 persons were classified as "believed missing" because no trace of their remains was ever found. Estimates of the injured are even less precise but appear to have been on the order of 3,500 persons. Although not all casualties were residents of Texas City, the total was equivalent to a staggering 25 percent of the towns estimated population of 16,000. Aggregate property loss amounted to almost $100 million (in 1947 dollars), not counting 1.5 million barrels of petroleum products consumed in flames, valued at approximately $500 million in 1947 terms. Refinery infrastructure and pipelines, including about fifty oil storage tanks, incurred extensive damage or total destruction. The devastated Monsanto plant alone represented about $20 million of the total. Even though the port's bulk cargo-handling operations never resumed, Monsanto was rebuilt in little more than a year, and the petrochemical industry recovered quickly. One-third of the town's 1,519 houses were condemned, leaving 2,000 persons homeless.

What caused the explosion? steam vapors probably liquefied the ammonium nitrate to produce nitrous oxide – an extremely volatile substance. It is also likely that the ammonium nitrate, which can itself produce the oxygen necessary to feed a fire, prevented the steam from dousing any flames. Steam also heated the internal compartments within holds 2 and 4, further escalating the core temperature of the vessel's cargo, up to 850 degrees Fahrenheit, the temperature at which ammonium nitrate will explode. Fuel oil, which lay in tanks between holds 3 and 4, may have ruptured the bulkhead and leaked onto the bags of ammonium nitrate, literally adding more fuel to the fire.

Sources: http://www.texascity-library.org/TCDisasterExhibit/tc1947p4.htm

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

5 commentaires:

Marie-Hélène a dit…

C'est une belle photo ! je lui trouve une atmosphère à elle ! j'aime la composition, les couleurs et les reflets !
Et l'histoire de cette explosion est terrifiante !!

Pierre a dit…

Magnifique vue et merci pour l'histoire.

claude a dit…

La photo est superbe, j'aime particulièrement les reflets dans l'eau transparente!

Ludopics a dit…

jolie reflet ;-)

don a dit…

The sharp reflection makes the image so clean and appealing. Very nice photo work.