Tank's Poetry
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united states mine rescue association
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Tank's Poetry |
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About 9:30 a.m., on Thursday, February 19, 1970, a roof fall occurred near the face of the North Main No. 1 entry, a development area on the 1,300-foot level. Preparations were being made to move a loading shovel to the face prior to the normal loading cycle. Five men were in the area at the time of the accident, four were killed and one received minor injuries.
General Information The Jefferson Island Mine of the Diamond Crystal Salt Company is a salt mine located at Jefferson Island, Louisiana. It is served by rail and by barge. The mine was opened by two vertical shafts 1,300 feet deep into a Gulf Coast salt dome. A total of 240 men was employed, of which number 70 worked underground, 3 shifts a day, 5 days a week. The average daily production was 6,000 tons of salt. There have been no disasters at this mine during its operation, which began in 1920. The last Federal inspection was completed October 29, 1969. Salt was mined by a modified room-and-pillar method. Since the terrain of Jefferson Island is barely above sea level (elevation at shaft 55 feet, above mean tide), prevention of subsidence is essential, and therefore, pillars were not extracted. Pillars in room sections were 75 by 100 feet. A sublevel, not indicated on the map, was developed by slopes from the mining level. Lower-level excavation and pillars were aligned with those on the working level and mined similarly. The floor pillar was drilled from the upper level, blasted, and then loaded from the lower level. Completely mined-out areas were 75 feet high. The roof was a hard and firm native salt. Timbering was not done, as the roof was generally self supporting. Rooms remained open for many years after they had been abandoned. The roof was examined daily by a designated person, and scaling was done with the scaling rig. The miners tested the roof before other work was begun. Rock bolts were used to support roof and ribs in questionable roof areas. Experience has shown that planes of separation above the exposed roof are always associated with intrusions of oil and some hydrogen sulphide, which was detected while drilling the face or stains on the salt following blasting. When these conditions were found, the roof was bolted according to plan. These indications were not present in the development area where the accident occurred. Therefore, the area was considered self supporting and roof supports were not used, based on past experiences. A safety organization was maintained, and a fulltime safety director was employed. Safety inspections were made by the safety committee and the safety director. Safety meetings were held weekly, and the plant and mine safety rallys were held every three months. Description of Accident About 9:30 a.m., Obra Suire, roof scaler, was preparing to handle the shovel cable when the shovel was moved. Lennis Landry, shovel operator, was walking toward the shovel to get into the cab and start the shovel. Josef Chrzanowski, general mine production foreman, was directing the moving of the shovel. John Hollier, mine production foreman, was near his pick-up truck. Apparently he was preparing to go to another part of the mine. The north main No. 1 face was blasted at 6:15 a.m. Johnson stated that he examined the roof before the men entered the area. Mine officials stated that the roof was examined and scaled with a scaling rig the day before the accident. Rivers Johnson (witness), front-end loader operator, was standing by the front-end loader near the face. In the meantime and without warning, an area of roof fell measuring 80 feet wide, 120 feet long, and ranging from 1 to 5 feet in thickness, killing Chrzanowski, Hollier, Suire, and Landry. Johnson received abrasions of the left am from flying material. A 2¾ cubic-yard shovel, a 30-ton haulage truck, and a 1½-ton pick-up truck were crushed by the fall. An examination of the surface of the fallen salt was made for planes of separation, but none was found. The pillar between the north main No. 1 and the north main No. 2 development entries near the face was 100 feet wide. Cause of Accident The cause of this accident was the inability to detect loose roof of this nature with present methods of roof testing.
4 Miner Killed When Salt Ceiling Collapses Oakland Tribune, California February 20, 1970 It was the worst mining disaster in Louisiana since March 6, 1968, when 21 salt miners lost their lives in Cargill's Belle Isle Mine. "I'm not sure what happened. I was sitting on my payloader at the 1,300-foot level and evidently from what I could gather some salt fell from the ceiling," said Rivers Johnson of Jeanerette, La., who was treated for slight injuries. The Jefferson Island mine was where a tourist was killed and four others hurt in 1964 when a slab of rock salt fell from the mine chamber roof at the 1,000-foot level. In 1968 the mine had to be evacuated when a fire damaged its electrical power plant. The dead men were identified as:
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