UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION


Southeastern District
Metal and Nonmetal Mine Safety and Health

Accident Investigation Report
Surface Nonmetal Mine

Fatal Exploding Vessels Under Pressure Accident

Richardson Road Quality Aggregates, Incorporated
Quality Aggregates, Incorporated
Sarasota, Sarasota County, Florida
Mine I.D. 08-00877

March 6, 1997

By

William L. Wilkie
Supervisory Mine Inspector

And

Mitchell Adams
Mine Safety and Health Inspector


Originating Office
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama 35209

Martin Rosta
District Manager

GENERAL INFORMATION

Michael A. Litzell, welder, age 27, was fatally injured at approximately 3:00 p.m. on March 6, 1997, when a sealed flotation tank exploded while the victim was attempting to weld a tie-off to the end of the tank. The victim had a total of 10 months mining experience, all at this site.

The victim reportedly had received 8 hours hazard training and placed with experienced employees for the remainder of his training. No documentation was available to verify that training had been conducted.

Doug Himes, safety director, Quality Aggregates, Incorporated, notified the MSHA Birmingham District Office of the accident at 3:09 p.m. on March 6, 1997. An investigation was started the same day.

Richardson Road Quality Aggregates, Incorporated, a shell and sand operation, owned by Quality Aggregates, Incorporated, was located at 6121 Richardson Road, Sarasota County, Florida. The principal operating official was Hugh N. Cannon, president. The mine normally operated one, 8-hour shift a day, five days a week and employed 33 persons.

Shell was mined from a single bench using a dragline and track-hoe excavator. Underlying sand was then mined using a suction dredge. The material was transported to the plant, where it was crushed, screened, and stockpiled. The final product was marketed as aggregate, base material, and concrete additive.

The last regular inspection of this operation was conducted on January 27, 1997.

PHYSICAL FACTORS INVOLVED

The company was in the process of replacing the flotation tanks on the dredge discharge line. The tanks, fabricated off-site by Kinney-Johnson Fabricators, Incorporated, measured 12 feet in length and 46 inches in diameter. They were fabricated from 1/8 inch thick metal.

The mine operator had purchased tanks in January 1997, and had welded tie-offs to the tanks without incident. The tie-offs were used to secure boats to the discharge line on the dredge during maintenance work.

The tanks delivered in January 1997, arrived at the mine with the vent caps missing and without rust-inhibiting paint being applied to the inside of the tanks. The tanks delivered on the date of the accident were sealed and the interior had been painted with a rust inhibiting paint at the order of the mine operator.

A copy of the material safety data sheet for the paint, provided by the fabricator during the investigation, stated: "Do not pressurize, cut, heat, weld or expose such containers to flame. They may explode and cause injury or death." There were no labels posted on the tanks warning of this hazard. The paint had a flash point of 103 degrees Fahrenheit.

The air temperature, on the day of the accident, was estimated to be in the mid 80's.

DESCRIPTION OF ACCIDENT

On the day of the accident, Michael A. Litzell, victim, reported to work at 7:00 a.m., his regular starting time. His primary occupation was maintenance welder.

He was assigned various duties in and around the plant until approximately 2:00 p.m. when two metal flotation tanks were delivered to the mine site. Litzell was to weld a v-shaped metal tie-off on both ends of each tank prior to the tanks being installed on the dredge discharge line.

He had completed welding the tie-off at one end of the tank, and was in the process of welding the tie-off at the opposite end, when the welding rod burned through the tank, resulting in an explosion.

The end of the tank, which was 46-inches diameter, separated from the body of the tank, striking the victim. He was thrown approximately 26 feet by the force of the explosion.

The explosion was heard throughout the plant and several employees went to the scene of the accident. The plant operator dialed 911 and summoned emergency medical assistance. The Sarasota County Paramedics arrived in approximately 10 minutes after being contacted and examined the victim. The victim was pronounced dead at the scene by paramedics from the Sarasota County Medical Examiner's office.

Death was attributed to multiple blunt force trauma caused by the explosion.

The victim was removed from the accident scene and taken to the morgue at the Sarasota Memorial Hospital.

CONCLUSION

The cause of the accident was the failure to ventilate the tank and test for flammable or explosive gases prior to beginning welding operations.

VIOLATION

Citation No. 4076847

Issued on March 19, 1997, under the provisions of Section 104(a) of the Mine Act for violation of Standard 56.4604:

On March 6, 1997, an employee was fatally injured when the sealed tank on which he was welding, exploded. Prior to beginning the welding operation, precautions were not taken to determine the presence of flammable gases and the vent cap was not removed to prevent pressure buildup during welding.

This citation was terminated on March 19, 1997. All employees were instructed in the importance of ventilating tanks and testing prior to welding or cutting operations.

[FAB97M15]