Maintenence Machinist Trainee Entangled in Revolving Shaft of Vertical Boring Mill

Wisconsin FACE 94WI373

SUMMARY:

A 22-year-old male maintenance machinist trainee (the victim) died after becoming entangled in a rotating shaft of a vertical boring mill. He was drilling holes in the concrete perimeter walls of a 32 inch deep machine pit that contained the boring machine. A 2½ inch diameter shaft extended vertically 9 feet from a baseplate on the floor of the pit to the upper portion of the machine. The shaft was unguarded and centrally located 16 inches from the machine edge, and 16 inches from the pit wall, and was rotating at a rate of 3-4 rotations a minute. The victim was apparently positioned adjacent to the shaft when the sleeve of his jacket was caught and pulled by the shaft and he was whirled around the shaft and his head struck the machine edge. A co-worker heard the victim yell, turned in his direction, and saw him caught on the shaft. The co-worker ran to the control panel, hit the emergency stop button, and went to his office to call 911. Another co-worker ran to the victim’s aid and attempted to suspend his body until rescue workers arrived. He was transported to the emergency room, where he was pronounced dead. The FACE investigator concluded that, to prevent similar occurrences, employers should:

• enclose/guard mechanical power-transmission equipment (e.g., vertical drive shafts), where the potential exists for an employee to become entangled or caught in the equipment.
• develop, implement and enforce a written safety program which includes, but is not limited to, worker training in hazard identification, avoidance and abatement.
• designate a competent person to conduct regular safety inspections.

INTRODUCTION:

On December 7, 1994, a 22-year-old male maintenance mechanic died after becoming entangled in the rotating shaft of a vertical boring mill. The Wisconsin FACE investigator was notified by the Wisconsin Department of Labor and Human Relations, Workers Compensation Division, on December 8, 1994. On April 11, 1995, the State FACE field investigator and a safety specialist from the National Institute for Occupational Safety and Health conducted an investigation of the incident. A visit was made to the site of the incident, and the company supervisor was interviewed. The investigator obtained copies of the death certificate, police and medical examiner’s reports, and OSHA reports. Photographs of the site taken immediately following the incident were obtained during the investigation.

The employer was a mining equipment manufacturer that had been in business for 15 years. The company employed 8 workers, 5 of whom were working at the time of the incident. The employer did not have a written safety program, but the supervisor reportedly conducted safety talks on a regular basis. New employees received on-the-job training in their assigned tasks, and worked side-by-side with experienced workers to increase their range of skills. This incident was the first fatality the company had experienced.

INVESTIGATION:

CAUSE OF DEATH:

RECOMMENDATION/DISCUSSION

Recommendation #1: Employers should enclose/guard mechanical power-transmission equipment (e.g., vertical drive shafts), where the potential exists for an employee to become entangled or caught in the equipment.

Discussion: The victim was working in proximity to an unguarded rotating vertical drive shaft when he became entangled and crushed against the machine’s frame. Exposed mechanical power-transmission equipment pose a serious hazard to employees and all such equipment should be identified throughout the plant and appropriate enclosures/guards installed to prevent inadvertent contacting with the equipment.

Note: the one shaft involved in the incident has been enclosed subsequent to the incident.

Recommendation #2: Employers should develop, implement and enforce a written safety program which includes, but is not limited to, worker training in hazard identification, avoidance and abatement.

Discussion: The victim was entangled in a vertical drive shaft and crushed between the shaft and the milling machine’s frame while performing tasks around the unguarded drive shaft. Employers should evaluate tasks performed by workers; identify all potential hazards; and then develop, implement, and enforce written safe work procedures addressing these issues. Although general safety procedures were reportedly used, no specific procedures existed for the task that was being performed by the victim. The safety program should include at a minimum, worker training in hazard identification, and the avoidance and abatement of these hazards. Workers should receive formal safety training pertinent to their work on a periodic basis. An effective training program includes a written job description containing step-by-step procedures, a list of the hazards within each step of the procedures, and an explanation of ways to overcome these hazards. Periodic safety training will increase employees’ awareness of the hazards confronting them.

Recommendation #3: Employers should designate a competent person to conduct regular safety inspections.

Discussion: Conducting regular safety inspections of all tasks by a competent person⁽¹⁾ will help ensure that established company safety procedures are being followed. Additionally, scheduled and unscheduled safety inspections of employee worksites clearly demonstrate that the employer is committed to the safety program and to the prevention of occupational injury.

Recommendation #4: Employers should encourage workers to actively participate in workplace safety.

Discussion: Employers should encourage all workers to actively participate in workplace safety and ensure that all workers understand the role they play in the prevention of occupational injury. In this instance, the victim apparently was working in proximity to an unguarded rotating vertical drive shaft and became entangled and was killed. Employers must instruct workers of their responsibility to participate in making the workplace safer. Increased worker participation will aid in the prevention of occupational injury.

REFERENCES

29 CFR, 1926.451 (a) Code of Federal Regulations, U.S. Government Printing Office, Office of the Federal Register.

ANSI A10.8-1988 – Standard for Construction and Demolition Operations – Scaffolding – Safety Requirements, 4.18 , P. 16. National Safety Council.

FATAL ASSESSMENT AND CONTROL EVALUATION (FACE) PROGRAM

FACE 94WI373

Staff members of the FACE Project of the Wisconsin Division of Health, Bureau of Public Health, perform FACE investigations when there is a work-related fatal fall, electrocution, or enclosed/confined space death reported. The goal of these investigations is to prevent fatal work injuries in the future by studying: the working environment, the worker, the task the worker was performing, the tools the worker was using, the energy exchange resulting in fatal injury and the role of management in controlling how these factors interact.

To contact Wisconsin State FACE program personnel regarding State-based FACE reports, please use information listed on the Contact Sheet on the NIOSH FACE web site. Please contact In-house FACE program personnel regarding In-house FACE reports and to gain assistance when State-FACE program personnel cannot be reached.

[1] Competent person: One who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has the authority to take prompt corrective measures to eliminate them.