Coverdale No. 8 (Bob Ciminel ©2012)
The Coverdale No. 8 Mine was located along the Montour Railroad between Library Junction and Brightwood. The mine’s surface facilities stretched along what is now Industrial Boulevard in Bethel Park. The mine was not serviced by the Montour Railroad. The West Side Belt Railroad received trackage rights (also known as running rights) on the Montour between Salida and Coverdale in exchange for granting the Montour Railroad trackage rights between Salida and Mifflin Junction.
The mine began operation in September 1920 and operated until 1948, although it was not abandoned and sealed until the 1950s. Coverdale was the last of the “alphabet mines” opened by the Pittsburgh Terminal Railroad and Coal Company. It was sometimes was referred to as the “H” Mine, although the tipple was labeled “Coverdale Mine.” Coverdale No. 8 was adjacent to Pittsburgh Terminal’s No. 4 Mine, also known as the “D” or Horning Mine, on the north, Montour No. 10 on the south and west, and Montour No. 4 on the east.
Coverdale had one of the largest “patches” in southwestern Pennsylvania. When the mine opened, Pittsburgh Terminal constructed 100 houses in two styles and 10 different color schemes with running water and electricity. Outdoor privies were originally used, but the company eventually installed a sewage system. The coal company planned on building 100 more homes in 1922 and still had enough room for 250 additional homes. Coverdale village overlooked “prosperous farming country with firm and well-kept roads.
Geologically, the mine was located on the McMurray Syncline, an underground valley, where the typically shallow Pittsburgh seam was 340 feet below the surface. Mines located on either side of the syncline could reach the coal through drift or slope entries dug into the hillsides and stream valleys. For example, Montour No. 10 accessed the seam through drift entries driven into the valley walls of Piney Fork. Shaft mines were obviously more expensive, but the cost was usually offset by the thicker coal at the bottom of the syncline. The seam at Coverdale averaged 66 inches in thickness.
In 1922, the Coverdale Mine complex was considered state-of-the-art because of the modern electrical system, hoisting equipment, and coal processing system Pittsburgh Terminal installed when they designed the mine.
Coverdale received alternating current (AC) power at 22,000 volts from transmission lines (probably West Penn Power) and put it through transformers to reduce it to 2,300 volts. The power then went to the main switchboard where it was either converted to direct current (DC) for use underground, or distributed to the various surface facilities, such as the main hoist,
auxiliary hoist, mine fan, and tipple. (Coverdale miners’ houses received their electricity from the coal company at cost.)
To produce DC power, the mine used two motor-generator sets with 2,300-volt AC, 433-horsepower motors to drive 275-volt DC, 300-kilowatt generators. Underground power went down the shaft in two cable encased in metal conduit. One circuit powered the overhead trolley wires and the other supplied power to the coal cutting machines. In 1922, the mine still used mules to haul coal from the working face to the shaft, but the electrical system was designed for the eventual installation of a rail haulage system using electric locomotives.
The fan house was a brick building that contained the 200-hp, variable speed fan motor driving the huge exhaust fan. As the mine expanded, plans were already in place to upgrade the fan to a 300-hp motor. A small diesel engine could be connected to the fan to operate it during power failures. Continuous ventilation to sweep methane gas out of the mine was one of the most important facets of mine safety.
The main hoist had its own generator to supply DC power directly to the hoist motor. A flywheel and strict regulation of current to the hoist motor allowed the hoist to operate at almost constant speed regardless of the load on the hoist. The main hoist only handled coal and slate and was rated at 5 tons of coal or 8 tons of slate (equivalent to two mine cars) using a 1.75-inch wire rope. The hoisting system was designed to handle 600 tons per hour, which equated to 240 mine cars an hour. The hoist could make a round trip in about 50 seconds.
The main shaft was rectangular with semi-circle ends and lined with concrete from the landing blocks to the shaft collar. It was topped by a 65-foot steel head-frame over the two hoisting compartments, which each contained a self-dumping cage capable of holding two 5,000-lb capacity mine cars side by side.
The Coverdale tipple was constructed of steel and concrete. The two mine cars that came up on the main hoist automatically dumped onto a scale at the top of the tipple. From the scales, the coal either went to a screening table or was diverted to the run-of-mine chute and directly into hopper cars. The use of circular picking tables was unique to the Coverdale Mine. They saved a lot of space compared to the rectangular tables used by most mines. Slate and rock were sent to a storage bin through air-operated gates and then taken out to the mine dump on an electrically-driven Larry car.
In 1931, the cleaning plant at Coverdale No. 8 was upgraded to 10,000 tons per day capacity and coal was washed in addition to screening, reducing the ash content from 10% to 5% and the sulfur content to less than 1%. At this time the mine produced Nut, Pea, Lump, Egg and Slack coal. Coverdale No. 8 had 21 electric mining machines, four loading machines, 17 coal drills and 10 shaker conveyors working in the mine. Transportation was provided by 13 trolley-
powered locomotives, seven shuttle cars, 48 steel coal cars and 526 wooden mine cars operating on six miles of 44-inch gauge track.
The following table lists production figures for Coverdale No. 8 between 1931 and 1946. The mine closed in 1948. The mine last operated under the ownership of the Castle Shannon Coal Company, but was owned by the North Star Coal Company when it was abandoned and sealed in the mid-1950.
YEAR TONS DAYS EMPLOYEES
1931 923,237 216 919
1932 851,284 195 879
1934 797,947 238 822
1936 894,612 231 822
1945 721,511 590