Excursion Meeting Of Students,

Seaham Harbour, July 10th, 1901.

About 40 students and associates visited the Dawdon and Seaham collieries.

Dawdon colliery is situated about 1 mile south of Seaham Harbour.

The Castlereagh or north shaft has a diameter of 21½ feet inside the walling, and will be reduced to a diameter of 20 feet, and has at. the present time attained a depth of 187 feet. The shaft is being lined with cast-iron tubbing, to an internal diameter of 20 feet: a wedging-crib was laid at a depth of 132 feet, the foundation-course is 1 1-8 inches thick, and there are 15 rings of tubbing, inch thick.

The winding-engine has two cylinders, each 24 inches in diameter by 4 feet stroke, the drum has a diameter of 8 feet and a width of 6 feet, and the locked-coil rope is 3¾ inches in circumference, and weighs 27 cwts.

The Theresa or south shaft is 21½ feet in diameter inside the walling, and will have a finished diameter of 20 feet. The depth to the bottom of the wedging-crib is 196½ feet. The winding-engine is of the same dimensions as that at the Castlereagh shaft.

Both of the present winding-engines will eventually be used for underground haulage.

The horizontal pumping-engine, with two cylinders, each 36 inches in diameter by 6 feet stroke, works two sets of pumps 24 inches in diameter, and one set 25 inches in diameter, and runs at 15 to 18 revolutions per minute. There are two Evans vertical sinking-pumps, with cylinders 24 inches and 16 inches in diameter by 24 inches stroke, capable of delivering 1,000 gallons per minute from a depth of 300 feet. The feeder of water at present averages 6,075 gallons per minute. A double-drum steam-winch, capable of lifting tons direct from each drum, is used for moving the Evans pumps, worked by cylinders, 8 inches in diameter by 10 inches stroke.

The main crab-engine has two horizontal cylinders, 14 inches in diameter by 3 feet stroke, it is geared at 16 to 1, and the crabrope is 6½ inches in circumference.

The ground crab-engine has two horizontal cylinders, inches in diameter by 14 inches stroke, it is geared at 30 to 1, and the rope is 5½ inches in circumference.

There are six Galloway boilers, 80 feet long by 8 feet in diameter, the furnaces are 3¼ feet in diameter, and steam is produced at a working pressure of 100 pounds per square inch. There are four sets of Green fuel-economizers, each with 120 pipes 9 feet long. The chimney, at present in course of erection, with a base 22 feet square, will have a height of 160 feet, and an inside diameter at the top of 12 feet. It is estimated that the total weight of the chimney will be 1,200 tons, and 360,000 bricks will be used in its construction. The estimated horse-power is 2,930.

The Mather-and-Platt water-softening tanks are each 15 feet 6 inches square by 10 feet deep, with a capacity of 15,000 gallons. The plant is capable of softening 60,000 gallons of water per day, and reduces the hardness from 16 degrees to 4 or degrees. A mixture of 40 pounds of lime and 7 pounds of alkali is used for each charge of 15,000 gallons of water. The cost of treatment is 0.58d. per 1,000 gallons.