Pumping Coal From the Bottom of Lake Michigan
The schooner Wells Burt foundered in Lake Michigan last fall with a cargo of 1,540 tons of coal, and the appliances used and the efforts recently made to recover the cargo are made the subject of a lengthy article in the Chicago Tribune from which the following is selected:
Among the apparatus selected was an eight inch centrifugal steam pump, which its manufacturers claimed would pump all kinds of coal not exceeding eight inches in diameter. Such a pump Capt. Dunham had found operating with success on an ocean wreck, but nothing of the kind had ever been used on the lakes. It was a new invention, and the manufacturers said that if it did not do all that they represented they would refund the money. The pump arrived in Chicago, and, as an experiment, was placed at work on the Wells Burt. The schooner A. Mosher was moored over the wreck with the pump on board. Pipes were attached to the pump and run down to the bottom of the lake. , connecting with a flexible hose that runs into the hold of the Wells Burt.
The pump is really a very simple device considering the wonderful work it performs. It consists of a bronze-metal wheel similar to the ordinary propeller wheel, only instead of four fans there are three. This wheel is encased in a cast iron box, and, when at work, makes from 300 to 400 revolutions per minute. A powerful steam engine propels the wheel. Owing to the inexperience of the engineer considerable difficulty was encountered in getting the pump started, but this was soon overcome. In the ordinary centrifugal pump a foot valve is attached so that the pump may be easily primed, but in pumping coal the foot valve cannot be used, as the coal would, as the coal would force the valve upward and allow the water to run out. This problem was overcome by attaching an air-syphon to the pump, and by sucking the air out rapidly the water was rapidly lifted.
After the pump was all ready for work a diver placed a suction hose among the coal and the pump commenced to revolve. A minute later a stream of coal and water came surging up the pipes. A large coal sieve was placed at an angle of 45 degrees at the edge of the hatch, the water and sediment passing through the sieve, and over the side of the Mosher, while the coal, thoroughly cleansed, was dumped into the hold. The coal passes through 53 feet of pipes, is pumped up at an average rate of 40 tons per hour, and is transported from the bottom of the lake to the hold of the Mosher entirely by machinery. The Mosher has already brought in one cargo, and is expected to return with another to-day. Monday the wreckers pumped up 200 tons. Yesterday a chunk of coal 15 inches long and seven inched thick came up the pipe besides other pieces from six to eight inches square. Several days ago a car-coupling, made of one and one-eighth inch iron, twelve inches long and four inches wide, was pumped up. Another proof of the success of the pump came up in the shape of a piece of board 18 inches long and three inches wide. So far 850 tons have been recovered and it is supposed that there are about 500 tons remaining. The diver thinks fully 200 tons of the cargo have been washed away.