Written for Mines and Minerals
The account of the disaster at the Cherry Mine of the St Paul Coal Co, published in the December issue of Mines and Minerals, was correct in so far as data were available at the time, excepting two statements. In that account it was stated that the fan was ordinarily run as an exhaust and that the main shaft was the downcast. It should have read that the fan ordinarily ran as a blower, and the main shaft was the upcast. The other inaccuracy was the statement that Messrs. Williams and Morris of the Urbana and Pittsburg Testing Stations descended to the bottom seam on Wednesday evening. This statement should have read 'to the upper seam.' Since that article was prepared a joint investigation has been carried on by the coroner's jury, a committee from the State Mine Inspectors, consisting of Messrs Thos. Hudson and Hugh McAllister, and the Illinois Mining Investigation Commission.
While the investigation cannot be completed until the mine has been unsealed, so that the conditions about the shaft bottom can be studied, the following facts have been brought out, the only break in the sequence of the story of the early stages of the disaster being the unaccountable absence of Alex, Rosenjack, the cager on the north side of the air-shaft, and Robert Dean, the cager on the south side. These men have mysteriously disappeared, and all efforts to locate them have thus far failed. their evidence, however, cannot materially affect the story as to the cause of the fire.
The accompanying illustrations give the details of the mine workings, all of the plans and sections being taken directly from the maps of the company, excepting Figs 6, 7 and 8 that are taken from sketches made by Mr. Geo S. Rice from the company's maps and here used by his courtest. Two seams of coal were being mined at Cherry; gthe upper, known locally as the 'Second Vein" is 232 feet from the surface. The strata through which the shaft was sunk are of interest on account of the caving about the bottom of the shaft at the second vein, which necessitated the extensive cribbing to be referred to in detail later, and which added so materially to the difficulty of extinguishing the fire. The log of the shaft is as follows:
Surface, 6 feet; yellow clay, 4 feet; blue clay, 12 feet; gravel and clay, 27 feet; hard brown clay, 6 feet; sandy clay, 3 feet; silt, 6 feet; green clay, 6 feet; blue clay and gravel, 5 feet; gravel and clay, 6 feet; gravel, 2 feet.
Ledge: Limestone, 6 feet; soapstone, 10 feet; limestone, 6 feet; black slate, 9 feet; blue shale, 13 feet; lime shale, 11 feet; blue shale, 15 feet; clay shale, 11 feet; soapstone, 2 feet; lime shale, 10 feet; brown shale, 2 feet; blue shale, 5 feet; red shale, 14 feet; lime shale, 10 feet; limestone, 29 feet; lime rock, 1 foot; sand rock, 21 feet; soapstone, 11 feet; black slate, 3 feet, coal, first vein, 37 feet; fire clay, 5.3 feet; lime shale, 16 feet; sandstone, 9 feet; soapstone, 9 feet; black slate, 3 feet; coal, second vein(323.2 feet), 5.2 feet; fireclay, 8 foot; lime shale, 3 feet; lime rock, 3 feet; limestone, 5 feet; blue shale, 14 feet; soapstone, 52 feet; blue shale, 4 feet; lime rock, 9 feet; black slate, 3 feet; black shale, 5 feet; blue shale, 3 feet; lime shale, 2 feet; sand rock, 21 feet; soapstone, 22 feet; black shale, 7 feet; soapstone, 4 feet; coal, third vein, 4 feet. Total: 485 feet. Sump: Clay and sand, 2 feet; sand rock, 14 feet.
The coal is about 5 feet thick, and is worked by the panel method. The roof above this coal varies from black slate to white sandstone, and is very defective in places. The floor is fireclay about 1 foot thick. The extent of the mine is shown by the sketch map. Fig 4 , that gives only the entry development, March 31, 1909. About 300 men were working in this seam at the time of the accident.
The La Salle third vein is found 485 feet from the surface. This is 3 1/2 feet thick, and was worked long wall, as shown in Fig 5 , which shows the development at about the time of the fire. The long wall portion of the mine had been opened up only about a year, and at the time of the accident, approximately 200 men were in this section. The room and pillar mine had been worked for about 5 years and workings had reached a distance of 3,000 feet north of the main shaft, about 2,000 feet to the east, about 2,500 feet south, and about 2,500 feet west from the main shaft.
It was the original intention of the coal company to work only the lower or long wall mine, as the middle vein is usually not particularly good in the Bureau County coal field in which Cherry is situated, but, owing to the better condition of the middle vein, it was extensively developed and the opening of the third vein postponed. The company had planned to discontinue work in the middle vein in the near future, which will account for some of the apparently temporary connections between the two veins and for the roundabout method of taking the coal to the surface from the lower vein as explained later.
The details of the shaft bottom of the room-and-pillar mine are shown in Fig 6 , and section through the two shafts along the broken line XX, Fig 6 is shown in Fig 7 .
both shafts extended from the surface to the lower seam, as shown in Fig 7 . The coal from the room and pillar working was hoisted through the main shaft and the cage for hoisting coal was lowered only to this level, where it rested on sump blocks placed across the shaft. On top of the sump blocks was an iron grating to prevent coal from falling to the bottom of the shaft. This grating could be removed if men were to be hoisted from the lower to the middle seam. In the shaft, between the middle and lower seams, there was an auxiliary cage for hoisting men. This could be attached to the underpart of the main hoisting cage by a rope, on the end of which there was a hook so that the end of the rope could be quickly attached to an eye under the cage, and the lower cage thus hoisted to a point just below the sump bars at the middle seam.