Fertilizer Tank Collapse

Aerial view of the tank collapse


A 1.2 million gallon above-ground storage tank used in the storage of liquid fertilizer catastrophically collapsed. The collapse resulted in a tidal wave of fertilizer product ten feet high that breached the surrounding earthen berm and entered a residential neighborhood as well as the Chesapeake Bay.


Artifacts from the failed tank required identification in the field that would provide evidence of the root cause of the failure. This required a detailed study of site and the position of the remnants of the tank.


Thielsch Engineering was retained to conduct the failure analysis of the tank shell and to develop and implement an inspection protocol for adjacent above-ground storage tanks. Select artifacts were chosen, cut up on site and sent to our Rhode Island facility for analysis. The metallurgical failure analysis conducted in our laboratory determined that a recent design modification to the tank attributed to the failure.


Based upon our investigation, the root cause was determined and appropriate legal actions were taken against the designer. In addition, based upon our site inspection of the other similar tanks, we were able to calculate and submit safe fill heights for them that allowed the owner operator to stay in business without requiring these tanks to be taken out of service.

Once the root cause of the failure was determined, we engineered an ultrasonic inspection procedure to evaluate the other tanks within the Virginia tank farm. This was carried out in the dead of winter and completed after 10 days on site.

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