DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Surface Nonmetal Mine
Fatal Powered Haulage Accident
Date of Accident: March 30, 2002
Date of Death: April 5, 2002
Midlothian Quarry and Plant
Midlothian, Ellis County, Texas
Michael C. Sanders
Mine Safety and Health Inspector
Michael A. Hockenberry
Fire Protection Engineer
Judy M. Tate
Mine Safety and Health Specialist
Mine Safety and Health Administration
South Central District
1100 Commerce Street
Edward E. Lopez
South Central District Manager
On March 30, 2002 Juan R. Hernandez, Sr., process assistant, age 67, was critically injured when he sustained thermal burns over 47 percent of his body. He died of those injuries on April 5, 2002. A rapid steam eruption occurred when hot clinker fell from a drag conveyor into standing water.
The accident occurred because procedures that required accumulated water to be removed from the tunnel floor prior to opening the inspection door of the enclosed drag conveyor were not followed.
Hernandez had 29 years mining experience, all at this operation. He had received training in accordance with 30 CFR, Part 46.
Midlothian Quarry and Plant, a surface quarry and cement plant, owned and operated by Texas Industries, was located in Midlothian, Ellis county, Texas. The principal operating official was James R. Owens, plant manager. The quarry and plant were operated three, eight-hour shifts, seven days a week. Total employment was 275 persons.
Limestone and shale were mined from a single bench quarry by ripping with a dozer and loading with a front-end loader on to haulage trucks for transport to the primary crusher. Crushed material was conveyed to the plant by conveyor for processing into Portland cement. The finish product was sold for use in the construction industry.
The last regular inspection of this operation was completed on May 9, 2001.
DESCRIPTION OF THE ACCIDENT
On March 29, 2002, Juan R. Hernandez, Sr. (victim) reported for work at 8:00 p.m., four hours prior to his normal start time, for voluntary overtime. Hernandez was briefed by the process assistant and started his normal duties.
On March 30, 2002, at about 4:00 a.m., Hernandez and Sylvester Gonzales, Jr., welder/repairman, were called to the 740 tunnel by Jerold Johnson, process supervisor, to unplug clinker material in the 740 enclosed drag chain conveyor. Johnson entered the tunnel by the access ladder at the west end where he noticed a pressure pad sensor outside of the housing. Johnson re-installed the device and several attempts were made to re-start the conveyor with no success.
By this time, Gonzales, Hernandez and Christobal Garcia, kiln oiler, arrived. They began opening top doors on the conveyor housing in an attempt to locate the plugged material. Hernandez opened a top door near the feed chute end of the conveyor and told Johnson, Gonzales and Garcia that he may have found the problem. They decided to open the clean out door from the side of the conveyor enclosure and allow the hot clinker to spill out onto the tunnel floor. Due to an accumulation of water on the floor in this area, a plan of rapid exit was discussed to escape the inevitable steam. Johnson, Garcia and Gonzales would travel up the tunnel incline to the head pulley and Hernandez would travel up a fixed ladder in the pit area by the chute end of the conveyor.
Gonzales and Hernandez removed the door retaining bars and while Gonzales held the door in place, Hernandez started up the ladder. When Hernandez was 2 or 3 rungs up the ladder, Gonzales allowed the door to open. Hot clinker spilled into the standing water producing a rapid steam eruption. Johnson, Garcia and Gonzales were about half way up the tunnel when Hernandez called for help. After several failed attempts, Gonzales managed to reach Hernandez, who was in the corner at the end of the tunnel, and assisted him out of the tunnel. Company emergency medical personal arrived shortly and Hernandez was stabilized. He was transported to Parkland hospital burn unit where he remained in critical condition until his death on April 5, 2002
INVESTIGATION OF THE ACCIDENT
MSHA was notified of the accident at 9:38 p.m., on March 30, 2002, by a phone call from Larry Ratliff, safety manager, to the MSHA National Office. On April 5, 2002, the MSHA South Central district office was notified that Hernandez had died from his injuries. An investigation was started the same day. MSHA's accident investigation team traveled to the mine, made a physical inspection of the accident scene, interviewed employees, reviewed training records and reviewed conditions and work procedures relevant to the accident. MSHA conducted the investigation with the assistance of mine management and miners.
It was routine for the chute to plug several times per week. When this occurred, it was the practice to remove a small access door located on the side of the conveyor enclosure directly under the inlet chute. This door measured 10 inches wide by 12 inches in height and was 55 inches above the floor.
The root cause of the accident was the failure to install an effective means to promptly remove the accumulated water from the 740 tunnel. The accident occurred because the hazards associated with the task had not been properly evaluated prior to opening the access door, allowing hot clinker to spill into the standing water causing a rapid steam eruption.
Citation No. 6217849 was issued on April 5, 2002, under provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.20003b:
A serious accident occurred on March 30, 2002, when an employee sustained thermal burns over 47 percent of his body. He later died of those injuries on April 5, 2002. A rapid steam eruption occurred when hot clinker was dumped from the 740 drag conveyor enclosure into six inches of water that had accumulated on the floor.
This citation was terminated on 6/21/2002, when a sump pump was permanently installed in the tail pulley area of the 740 Drag Conveyor. Additional training had been given to employees assigned to work in the tunnels regarding steam hazards.
Related Fatal Alert Bulletin:
James R. Owens .............. plant managerMine Safety and Health Administration
Brian L. Bottelberghe .............. production manager
Gerold L. Kuykendall .............. assistant plant manager
Daniel W. Paine .............. safety coordinator
Larry L. Ratliff .............. safety manager
Brian L. Bottelberghe .............. production manager
Michael C. Stripe .............. corporate safety & health
Todd A. Camp .............. quality control supervisor
Gregory S. Boston .............. maintenance supervisor
Marla S. Christenson .............. administrative supervisor
Ronda L. Barker .............. senior administrator assistant
Mickey B. Blankship .............. pyro process supervisor
Michael C. Sanders .............. mine safety and health inspector
Michael A Hockenberry .............. fire protection engineer
Judy M. Tate .............. mine safety and health specialist
Sylvester R. Gonzales .............. welder, repairman
Gerrell L. Leonard .............. welder, repairman
Michael P. Dickerson .............. kiln oiler
Christobal Garcia .............. kiln oiler
Rickey R. Poff .............. process supervisor
John M. McCutchem .............. process supervisor
Jerald R. Johnson .............. process supervisor
Kelley J. Pitner .............. process supervisor
David E. McGraw .............. process supervisor
Silas W. Simmoms .............. process supervisor
Michael L. Conner .............. process assistance
Douglas R. Jeffers .............. protective service
Vernon J. Miller .............. protective service