## Facts

- William T. Dempsey worked as a pile driver on a construction project in Washington, D.C., during an excavation phase.
- The general contractor rented a crane, with an operator, from Addison Crane Company, Inc., which rented and operated cranes for others.
- The crane was directed to move a welding machine on site; four pile drivers, including Dempsey, steadied the machine by holding its corners to prevent twisting while it was being positioned.
- An auxiliary jib attached to the crane boom, carried along the boom but not used in the welding-machine move, broke loose, fell, and struck two of the workers; one was killed and Dempsey was seriously injured.
- The auxiliary jib had been suspended along the boom using wire-rope slings secured with open hooks; the slings were made by Addison Crane.
- Dempsey’s wife asserted a derivative claim for loss of consortium.
- The case was tried to the court without a jury, with liability tried first and damages reserved for later.

## Issues

1. Whether it was negligent to keep an auxiliary jib suspended on the crane boom during an operation in which the jib was not being used.
2. Whether using an open-hook sling system to suspend the auxiliary jib breached the duty of reasonable care, even if the method was common in the industry.
3. Whether the suspension method caused Dempsey’s injury and whether any contributory negligence or assumption of risk barred recovery.

## Decision

- The court found no negligence in merely having the unused auxiliary jib suspended along the boom during the move.
- The court found Addison Crane negligent in using an unsafe open-hook method to suspend the jib when safer closed connections (including shackles) were available.
- The court found causation satisfied because the jib’s detachment and fall resulted from the insecure suspension method.
- The court rejected contributory negligence and assumption of risk defenses.
- The court held Addison Crane liable to both plaintiffs, reserving the amount of damages for a later proceeding.

## Legal Principles

- A supplier-operator of equipment is not an insurer of safety but must exercise the care a reasonably prudent person would use under similar circumstances.
- Evidence of industry custom is relevant to due care but does not set the legal standard; common practice may still be negligent if it falls below reasonable prudence.
- Continued use of a customary but unsafe device can be negligent when a safer alternative is practical, readily available, and inexpensive relative to the risk of serious harm.
- A plaintiff following work instructions without control over the hazardous configuration is not necessarily contributorily negligent and does not assume a risk he did not knowingly and voluntarily accept.

## Conclusion

The court imposed liability on the crane lessor-operator for injuries caused by an insecure open-hook suspension system for an auxiliary jib, holding that widespread industry use did not excuse a failure to take a simple, low-cost precaution that reasonable care required.


Dempsey v. Addison Crane Co., 247 F. Supp. 584 (D.D.C. 1965)