Crane Accident Case Studies: How Expert Analysis Determines Liability

Case Study 1

Tree Worker Falls After Being Hoisted by Crane

What Happened

A tree climber was working a crane-assisted tree removal on a residential property. After more than eight hours of work, the climber told the crane operator — who was also the owner of the tree service — that he was fatigued and wanted to stop for the day. The operator agreed to a short break but then called the climber back to work after only five minutes.

The climber tied off to the crane's hoist line using a carabiner-style attachment and was lifted into the tree canopy by riding the crane hook — a practice that raises serious safety and regulatory concerns. During the hoist, branches struck both the crane ball and the worker. Once in position, the climber secured himself to the tree, rigged a branch for removal, and signaled the operator to take weight on the strap.

When the operator hoisted and the strap went taut, the climber sat back into his harness expecting a slight drop of an inch or two. Instead, he kept falling.

What the Investigation Found

The expert review of depositions, equipment records, and photographs revealed a pattern of systemic safety failures by the crane operator/owner:

• Disabled safety systems. The operator routinely refused to use the crane's manufacturer-supplied operating computer — a system that provides real-time load weight, boom angle, boom length, and radius data. By disabling this system, the operator also disabled the crane's anti-two block device, which is required under OSHA 1926.1431(d)(5)(v) during all personnel hoisting operations with no exceptions.
• Exceeding rated capacity. The operator admitted in deposition to adding logs from felled trees to the crane's outriggers and deck to weigh it down — a practice known as "tying down" a crane. This is extremely dangerous because it can push the crane beyond its structural design limits, causing component failure. The operator also incorrectly claimed that removing the stowed jib from the boom allowed him to add that weight back to the crane's capacity — the opposite of how load chart deductions work.
• No inspection records. The operator admitted to performing no documented daily, monthly, or annual inspections — violating OSHA 1926.1412. Without these inspections, there was no verification that the crane's safety devices, structural components, or rigging were in safe working condition.
• Damaged boom. Records showed the crane's boom had been sent to a repair shop. A repaired boom is a load-sustaining structural component that requires recertification and documentation — neither of which existed.
• Defective tie-off point. Before the lift, the climber had complained that the carabiner's double-safety lock wasn't functioning properly and the latch had to be forced open and closed. The operator dismissed the complaint.
• Refused to reposition. Rather than moving the crane closer to improve alignment and increase safety margin, the operator chose to push the machine's capacity from a less favorable position — a decision driven by time savings rather than safety.

Key Standards Violated

• OSHA 1926.1431 — Hoisting personnel without a functioning anti-two block device
• OSHA 1926.1434 — Unauthorized equipment modifications (adding counterweight beyond manufacturer specs)
• OSHA 1926.1417 — Operating in excess of rated capacity; failure to comply with manufacturer procedures
• OSHA 1926.1412 — No daily, monthly, or annual inspection documentation

Expert Conclusion

The operator's pattern of deliberately disabling safety systems, refusing to perform inspections, exceeding the crane's rated capacity, and ignoring worker complaints created the conditions that led directly to the accident. The incident would not have occurred if the operator had followed the minimum safety standards established by OSHA and the crane manufacturer.

Case Study 2

Overhead Crane Accident Caused by Improper Rigging — Not Equipment Failure

What Happened

A laborer at a concrete manufacturing facility was tasked with rotating a 12,000-pound precast concrete headwall into an upright position using a 10-ton overhead bridge crane. Instead of using the manufacturer-installed lifting points on the headwall — which were specifically designed for this purpose — the worker attached the crane's chain bridle to coil rods threaded into the concrete.

Coil rods are coarse-threaded rods designed to hold concrete forms in place during the pouring process. They are not rated lifting devices — they carry no manufacturer weight rating, no safety markings, and are not designed to bear suspended loads.

As the worker hoisted the headwall, one coil rod partially broke under the dynamic loading. The worker noticed the failure, stopped the lift, and began lowering the piece back to the ground. As the headwall touched down — still under tension — the damaged coil rod snapped completely. The sudden release transferred all the weight to the opposite side of the chain bridle, creating a shock load that broke the second coil rod. The headwall dropped and the worker was injured.

What the Investigation Found

The expert analysis focused on three critical failures:

• No training or certification. The worker had been employed for only two weeks and had received no formal training on operating the overhead crane. Multiple depositions confirmed this — the company's HR and safety director, the quality control supervisor, and the worker himself all acknowledged that no training on this crane or this procedure had been provided. Under ASME B30.2-2005, Section 2-3.1.3, crane operators must pass a practical operating examination for the specific type of equipment being operated.
• Improper lifting devices. The coil rods used to lift the headwall carried no weight ratings and had never been tested for tensile strength. Under ASME B30.26, all rigging hardware must have manufacturer markings showing the rated load and a design factor of 5:1. The coil rods met none of these requirements. The headwall had manufacturer-installed lifting points that should have been used.
• Dynamic loading not accounted for. All loads being hoisted are loads in motion and generate forces — known as dynamic loading — that exceed the static weight of the object. With properly rated rigging hardware, the built-in safety factor accounts for these forces. Because the coil rods had no rating at all, it was impossible to account for dynamic loading, making failure predictable.

Opposing Expert's Errors

The opposing expert attempted to shift liability to the crane inspection company, arguing that the inspector should have locked out the crane and prevented its use. This analysis was incorrect on several grounds:

• Under ASME B30.2-2005, Section 2-3.5, the responsibility for taking a crane out of service lies with the crane owner, not the inspector
• The opposing expert conflated the OSHA definitions of "competent person" and "qualified person" — two distinct roles with different authority levels
• Both the crane inspection company's inspector and a previous inspector from a different firm confirmed in deposition that they did not have the authority to lock out the crane or apply a red tag — that responsibility belonged to the equipment owner
• Most importantly, the crane condition was irrelevant to causation — the accident was caused by the use of unrated coil rods as lifting devices, not by any malfunction of the crane itself

Expert Conclusion

The crane did not cause or contribute to this accident. The root cause was the use of coil rods — hardware not rated or intended for lifting — instead of the manufacturer-installed lifting points. Contributing factors included the worker's lack of training, certification, and authorization to operate the crane. The crane inspection company followed all applicable ASME and OSHA standards.