Safety Assessment Program Evaluator Student Manual

CA Emergency Mgmt. Agency Safety Assessment Program Evaluator Manual April 2011Granary explosions are historically rather common, and are the chief reason why granaries arebuilt of concrete or masonry instead of wood.Figure 6-25 shows a slab of road asphalt that was flung into the position shown in the photo bythe 2010 San Bruno natural gas explosion, in which a 30 inch pipeline ruptured and exploded.Asphalt projectiles landed all over the vicinity of the explosion, including one the size of a smallcar that fell through the roof of a house.The 1947 Texas City, TX ammonium nitrate explosion event destroyed or damaged much of thatsmall community. The photos found in this manual only show small pieces of the incredibleoverall damage picture. In Figure 6-26, the parapet of this small building was peeled off by theforce of the blast. It is interesting that only part of the building was damaged this way; the restmust have been shielded from the blast by a structure in front of it. Note also the debris on thesidewalk. This photo was taken after the streets were cleared of debris.Figure 6-27 shows part of the heavily damaged community in Texas City. Note the building onthe right side of the photo that became a projectile and is seen lying on its side atop anotherbuilding. Several buildings in the foreground are flattened.Figure 6-28 shows the wreckage of a fire engine tossed on top of the remnants of a barge. Thebarge ended up on shore due to the tsunami-like surface wave that resulted from the explosion.Finally, Figure 6-29 shows the extent of the projectile issue in Texas City. It takes between 6 psiand 8 psi of blast force on the side of an automobile to make it airborne. These particularvehicles are showing complete disregard for the “do not park here” sign.Photo courtesy Texas City Fireman‟s UnionFigure 6-26 – Damaged parapet, 1947 Texas City explosion205