Crane lifts huge sheet of metal from riverbed after oil tanker fire

[webfact]

 

A floating crane was deployed on Saturday to salvage a huge metal sheet from the bottom of the Mae Klong River in Samut Songkhram Province, following the explosion of an oil tanker at a dockyard in Mueang district.

 

A shipping company official said that it took about two hours to lift the steel sheet, which is 14m long and 8m wide and was part of the oil tanker Smooth Sea 22, from the bottom of the river, adding that several other metal sheets are still underwater.

 

A buoy has been anchored in the river to warn other vessels of the presence of metal sheets below the surface, while the Marine Department has advised fishing vessels to avoid the area.

 

Full story: https://www.thaipbsworld.com/crane-lifts-huge-sheet-of-metal-sheet-from-riverbed-after-oil-tanker-fire/

 

-- © Copyright Thai PBS 2023-01-23

 

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[hotchilli]

I did watch the explosion in the various videos but boy that must have had some power to tear off and throw those sheets into the water.. 

[degrub]

Ordinary hydrocabon vapour will expand by a factor of around 8x during combustion under optimal conditions. For a completely closed container, this means the pressure inside can rise by a factor of 8-10x absolute starting pressure. So, in this case, assuming the container was at atmospheric pressure (~ 14.7 psia), then maximum pressure would be in the range of 117.6 to 147 psia or 102.9 to 132.3 psig ( guage accounts for the atmospheric pressure pushing back on the other side of the wall).

 

For low to moderate vapour pressure hydrocarbons, a container would be designed to contain roughly 10- 15 psig of internal pressure. The rupture of that container might occur at approximately 4x design pressure due to mechanical safety factors prescribed in design codes, so, 40 - 60 psig maximum. A ship tank may be designed to a higher pressure due to the need to resist forces from the motion of the ship and the liquid in the tank.
 

clearly, the pressure developed during combustion can exceed the maximum design in the example. The roof of the ship tank may be designed as a relief device just for this internal fire case by using weak welded seams that will fail at lower internal pressure, perhaps as low as 20 psig. This to ensure that the rupture occurs on the top and protects the integrity of the ship hull.

 

if the roof of the tank had the dimensions of 30 ft x 30 ft giving an area of 900 square feet and the rupture occurred at 20 psig or 2880 psfg, then the total applied force might be about 2.6 million pounds of force.

 

All of that is another way of saying, yes, that might throw the plate a good distance. The blast and fireball radiation would kill anyone in the area from lung collapse or severe burns. Blast at that level would rupture eardrums making it impossible to walk and evacuate.