Fatality Assessment and Control Evaluation (FACE) Program
Mechanic Dies while Changing a Tire Mounted on a Multi-piece Split Rim Wheel - Massachusetts
On December 31, 2007, a 59-year-old male mechanic (victim) was fatally injured while changing a container handler’s dual front inner tire that was mounted on a multi-piece split rim. While removing the outer multi-piece split rim wheel to access the inner wheel, it exploded off the container handler striking the victim and pushing him into the mast of a forklift. A co-worker found the victim lying on his back on the ground with the outer tire on top of him. The co-worker placed a call for the local police; personnel from the local police and fire departments arrived within minutes. The victim was transported to a local hospital where he was pronounced dead. The Massachusetts FACE Program concluded that to prevent similar occurrences in the future, employers should:
On December 31, 2007, the Massachusetts FACE Program was alerted by the local media that on the same day a 59-year-old mechanic was fatally injured when he was struck by an exploding tire. An investigation was initiated. On January 25, 2008, the Massachusetts FACE Program Director traveled to the company’s office and the incident location. The police report, death certificate, and company information were reviewed during the course of the investigation. In addition, photographs were taken of the incident location and the container handler, the vehicle involved in the incident.
The employer is an international intermodal freight transport company that includes cargo container terminal locations and rail and trucking transportation. The company also provides warehouse and full service maintenance services. The company has been in business for 23 years and has multiple locations in the state. The company location where the incident occurred had been in operation for 16 years. The company employs approximately 80 employees, 17 of whom hold the same job title as the victim, mechanic. The victim had worked for the company for eight years and was a career mechanic.
The company did not have a designated person in charge of employee safety and health or a written safety and health program. The company did have a safety committee and buddy system for employees. The company stated that they typically hire employees with previous experience and provided minimum employee training. Training on the proper operation and maintenance of the container handler was provided by the manufacturer of the container handler to the mechanic supervisor and machine operator supervisor. These supervisors would then train the mechanics and machine operators. It was reported that the company had standardized verbal procedures and some generic written practices for changing tires on the equipment. Employees were not part of a collective bargaining unit.
The company, an international intermodal freight transport company, receives international shipment containers via railroad. The machine on which the victim was working when the incident occurred was a container handler (Figure #1). Container handlers are used to move large metal cargo containers (Figure #2) and are equipped with large hydraulic lifting arms located in the front of the machine. The company’s main tasks once a cargo container arrives onsite are to ensure the containers are cleared by customs and then released to their owners or designees. The container handlers are used to pick the cargo containers up off the railroad cars on which they arrived and move them either to the company’s storage location, or onto one of the company’s flatbed tractor trailers or another company’s flatbed tractor trailer to be transported to another location.
The container handler involved in the incident was manufactured and purchased in 1999 and was one of eight container handlers that the company owns. This container handler has a diesel fueled engine, an operator’s area with a totally enclosed cab, and it can lift approximately 100,000 pounds. To lift a container, the container handler’s lifting arms are lowered to the top of a large cargo container and are latched onto the container. Once the cargo containers are attached to the container handler’s lifting arms, the containers are lifted and moved horizontally to a storage location where the container can be stacked onto other cargo containers or onto the flatbed trailer section of a tractor trailer or train.
This container handler is equipped with six wheels, four in the front (dual wheels) and two in the rear. All of the wheels are multi-piece split rim wheelsa with 21.00x25 size tubeless rubber tires (approximately 23 inches wide and 69 inches high) (Figure #3). These multi-piece split rim wheels consist of five components, an inner and an outer rim, a collar, and two rings, one of which is a locking ring. The front outer wheels of the container handler are each fastened to the vehicle’s axle with 28 lug nuts and clips. The company reported that this container handler had not been altered and that maintenance schedules are followed for all equipment. Most of the equipment maintenance is performed onsite by the company’s mechanics.
The incident occurred on a Monday, which was the first day the victim was back at work after a few days of vacation. On this day, the victim arrived to work at 7:30 a.m. The night before the incident there had been light snow, and the morning of the incident the weather was clear with temperatures in the 30’s.
One of the first jobs to be performed on the day of the incident was to repair the container handler involved in the incident. Due to the large size of these containers handlers, all of the maintenance tasks were performed outdoors. The task to be performed was to repair a flat tire on the front left inner wheel caused by a piece of metal that had been run over the Friday before. To access the wheel with the flat tire, the left front outer wheel, which was fully inflated, had to be removed first. The company reported that the left front outer wheel rim was original to the container handler and appeared to be in good shape. It was reported by the company that changing container handler tires was a job that that they routinely performed.
The procedure for changing a container handler’s tire, as explained by the company representative, included, but was not limited to, first jacking up the container handler so only the tire(s) to be removed are off the ground. Then 22 of the 28 lug nuts and clips on the outer rim are removed and the six remaining lug nuts and clips should be in a star-like pattern. These remaining six lug nuts and clips are then loosened but not removed. It was reported that the rims will typically stick to the break drum and that the wheel is usually struck with a hammer to loosen it from the break drum. Once the outer wheel is loosened, a forklift is used to help lift and remove the tire from the axle and then move the tire out of the immediate area. Now accessible, the inner wheel is loosened and removed.
The victim had been working on changing the tire with a co-worker on the morning of the incident. At the time of the incident, the victim’s co-worker had gone to the bathroom, and the victim continued to work at removing the outer wheel to access the inner flat tire. It was reported that the container handler was jacked up so that the two left front wheels, the wheels being removed, were off the ground. It was also reported that all 28 of the lug nuts on the outer rim had been removed at the time of the incident.
The incident was not witnessed, but it appears that the victim was standing directly in front of the wheel and reportedly using a hammer to hit the outer split rim to loosen it from the break drum. The split rim wheel exploded off the container handler striking the victim. The victim was thrown backward approximately 12 feet and struck the mast of a forklift. The forklift was positioned with its tines lowered and facing the container handler’s wheel in preparation to be used to lift and move the wheels off the container handler’s axle.
When the victim’s co-worker returned to the task location, he found the victim against the forklift’s mast with the container handler’s left outer tire on top of him. The co-worker placed a call for the local police. Personnel from the local police and fire departments arrived within minutes. The victim was transported to a local hospital where he was pronounced dead.
After the incident, it was discovered that the front left outer multi-piece split rim failed and had a crack within an inch of the rim’s interior ring (Figure #4). During the site visit, the split rim that failed looked worn, rusty and had some pitting. The company stated that they were going to start conducting routine inspections of all of their multi-piece rim wheels. In addition they were now going to hire a tire company to maintain all of the container handlers’ wheels.
Cause of Death
The medical examiner listed the cause of death as blunt head trauma with skull fractures.
Recommendation #1: Employers should ensure that all multi-piece rim wheel tires are deflated prior to removing them from a vehicle’s axle.
Discussion:This case underscores the importance of always deflating multi piece rim wheels prior to maintenance or removal from a vehicle. When multi-piece rim wheels are inflated, they are under great air pressure. It is this air pressure that holds the multiple components of the multi-piece rim wheel together. When there is an uncontrolled release of the air pressure from the tire, this causes the rim wheel components to separate. When the rim wheel components separate, they are usually dislodged causing them to be thrown at extreme speeds and violent force. Therefore, prior to removing a multi-piece rim wheel from a vehicle’s axle, the tire should first be completely deflated by removing the core valve.
In this case, the container handler had dual wheels and the wheel that the victim was attempting to repair was an inner wheel. Although the outer rim wheel was not the wheel to be repaired, it had to be removed from the vehicle to access the inner wheel. It does not matter if only one of the dual wheels is in need of repair. The first step that should be performed, even before loosening and removing any lug nuts, is to completely deflate both tires.
Figure 5 – Trajectory of multi-piece rim parts in different scenarios.
To contact Massachusetts 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.