Introduction: A pipe segment suspended by bull rigging shifted during a construction project and fatally struck a worker. We were engaged in determining the cause of the incident and identifying the regulations applicable to using bull rigging in construction. In addition to opinions on training and competence, our report included an expert opinion on the relevant human factors.

Bull rigging is the term used to describe a method or system of rigging commonly used to facilitate lateral movement of a heavy load in places where a crane cannot gain access. Bull rigging might also be called drifting or "Tarzaning.” The most commonly used bull rigging equipment includes chain falls, come-a-longs, winches, and rigging blocks. In addition, bull rigging may remain in a position to hold a suspended load in place long after the crane has left the scene.

During a refinery expansion project, some new pipe was required to be installed on a fourth level of a pipe rack. After the section of pipe was placed, bull rigging held it there for over a month until its final installation. The rigging required adjustment for final alignment on the day the line was to be welded in place. The pipefitter installed another chain fall and sling in a location for alignment. While lowering the pipe segment to reattach the sling in another place, the pipe shifted, and its elbow-end rotated downward, fatally striking a worker.

Baker & O’Brien was engaged in identifying the cause of the incident, the applicable regulations, company procedures, and site responsibilities. The issues included training, competence, and the applicability of the OSHA regulation for cranes in construction to the use of bull rigging. We were also retained to opine on the relevant human factors. We issued an expert report with our opinions. Before the trial, the parties negotiated a settlement.