Construction of an odor control vapor recovery piping project at an oil storage terminal resulted in significant consequences when welding on the tank roof triggered a fire and explosion. Baker & O’Brien was engaged to determine the incident's critical factors, direct cause, and associated regulatory and procedural responsibilities. Our expert report of opinions regarding the failures and faults facilitated mediation, which was settled before the trial.

It was planned to be a simple modification. A pipeline terminal operator engaged a construction contractor to fabricate and install a vapor recovery system for odor control on certain atmospheric oil storage tanks. The project required the connection of piping to the tank roof nozzles. Pipe segments for the vapor were fabricated offsite and would require pipe supports when installed on the tank roofs.

While welding a small iron pad for mounting the pipe support onto a tank roof, heat generated by the welding likely ignited hydrocarbon vapors inside the storage tank. The vapors inside the tank exploded, causing the tank to deform and the welder to fall to the ground.

Baker & O’Brien was retained to determine the risk management control failures that permitted the incident to happen. Like slices of Swiss cheese, a risk management system usually contains several preventive (redundant) layers of protection, each with inherent points of failure (holes). As the Swiss cheese metaphor illustrates, sometimes the holes of the various layers of defense overlap (simultaneous failure), leading to a systemic loss of protection and a higher probability of an incident.

Baker & O’Brien identified the applicable regulations and evaluated the terminal operator and contractor’s safe work practices, including the hot work permit procedures that served as preventive controls. We reviewed the depositions and witness statements to establish a timeline of conditions and events and analyzed the evidence to establish the critical factors and incident causes. We produced an expert report of opinions describing responsibilities for the control failures, which was used during the mediation proceedings. The matter was settled before going to trial.