One of the means to protect an OUTSIDE atmospheric storage tank is a weak roof-to-shell seam. As we can see in this video, a diesel tank at a wharf in Apia, Samoa was equipped with such a means of fire venting. I am assuming this on the basis of the information we can obtain from the drone footage. We see the other two (2) diesel tanks do NOT have a normal emergency vent and the fact that the entire roof is gone on the tank that is on fire. This means of emergency venting is permitted ONLY on OUTDOOR tanks and we can see why, but they do work. Had the responding FD had an adequate supply of foam, this fire could have easily (relatively speaking) extinguished. Notice how the tank integrity was maintained and the diesel was contained within the tank.
NOTE: this tank fire was caused by Hot Work on the tank while the tank was in service. Diesel fuel will EXPLODE and in fact it’s LEL is HALF of Gasoline’s LEL!!! Of course it’s FP is 145F, but once we get vapor present, it takes only 0.5% to be explosive!
Drone Footage Shows Apia Fuel Storage Tanks Fire by storyfulviral
CLICK HERE to see the location of the tank roof and additional footage.