1873 - Old Forge Coal Mines

INSPECTORS OF MINES. 63
it being 18 inches diameter in working barrel ; the two top sets are each 12
inches diameter, and lift the water to top of shaft, being 50 fathoms more.
It is here desired to know the probable amount of units of labor required
to overcome the whole weight of spears, spear plates, wye ends, swords,
joints, buckets, clacks, clack bows, bolts and nuts, together with the column
of water. The 18-inch pump is worked by spears 6 inches square ; the 2
12-inch pumps are worked by spears 4^ inches square, each set made of
memel timber, in 20 feet lengths, or 60 joints in both sets of spears.
Rule to calculate the spears.—Multiply the side of the spear into itself,
and is called the square, then multiply by the number of fathoms in the
shaft, then by the number of feet in a fathom=6 feet. Multiply by 12 the
inches in a foot, then divide the whole by the number of cubic inches in
one pound, of which mamel fir contains 48.876 cubic inches to 1 pound.
Operation.—6X6X100 fathomsX6X12 inches=259200 cubic inches-=-
46.876=5530 lb=weight in pounds of 6 inch spears.
Then: 4.5X4.5X100X6X12=145800 cubic inches=46-876=3111 lb.=
weight of 4^ inch spears.
60 spear plates, 5 inches by f inches 'thick in the middle, taper to f at
the ends for 18 inch pump. Hence average thickness=4 inchX5 inches
broad X 9 feet longX 3.33X60=4495 lb. weight of large spear plates.
60 platesX4iXi thickX9 feet longX3.33X60=4045 lb. weight of small
spear plates.
480 by | inch bolts and nuts for spear plates=1680 lbs. The total of
these valves is as follows, viz.: 5530+3111+4495.8+875 + 1680=19763.8
lb.X.66, for modulus or friction of pump.=13026.288+ 19736.8 lb=32763
lb.
The column of water, the weight of which is required to be obtained.
Square the diameter of each set of pumps in inches, multiply by .7854, this
will bring them into square inches ; add the square areas of the three pumps
together, multiply by 50 fathoms, multiply by 6 feet, multiply by 12
inches, and divide by 27.648 cubic inches of water in 1 lb., this gives 62582.
942 lb.=whole weight of water. Then plus 32763 lb. weight of spears,