Woodhorn colliery, one of the Ashington group of collieries, lies about 1½ miles east of Ashington, and between 4 and 5 miles north of the port of Blyth. There are, at present, two shafts, both sunk to the Plessy coal-seam, at a depth of 864 feet.

Downcast Shaft. — The downcast-shaft is 13 feet in diameter, and is used exclusively for drawing coals from the Yard seam at a depth of 573 feet.

The winding-engine, fitted with Cornish double-beat drop-valves and trip-gear, has two cylinders, each 30 inches in diameter by 6 feet stroke, and the drum is 16 feet in diameter. Steam is supplied at a pressure of 80 pounds per square inch. There are two double-decked cages, each deck taking 2 tubs. The tare of the tubs is about 5 cwts. and the average weight of coal per tub about 9 cwts. Steel rail-guides, weighing 15 pounds per foot, are fixed to the shaft-buntons by means of cast-steel sleepers.

The screening-plant and heapstead comprise two vibrating screens for best coal; two cleaning-belts, 60 feet long by 4½ feet wide, running parallel to each other, and a stone-belt is placed between them.

After being weighed, the full tubs pass into Wood-and-Burnett revolving side-tipplers, placed immediately over the best-coal screens. The empty tubs, from both tipplers, gravitate to a point, where they are raised by means of a creeper until they are high enough to run to the back of the shaft. Directly under the best-coal screens a cross belt is placed for elevating small coal to another vibrating-screen, where this class of coal is further divided into nuts and peas. At the delivery-end of the best-coal belts, there are also further vibrating screens, which can be used for making double nuts, if necessary and when not required for this purpose, by means of dead-plates they form the spouts for easy delivery of the best coals into the trucks. Beneath the double-nuts screens is another cross-belt for conveying the nuts to tucks on an adjacent line of rails.

The whole of the screening-plant is driven by shafting and belts by an horizontal engine, with one cylinder 13½ inches in diameter by 24 inches stroke, running at 88 revolutions per minute.

Upcast Shaft. — The upcast-shaft, 15 feet in diameter, is fitted as a winding-shaft in a similar manner to the downcast-shaft, and is used for raising coals from the Low Main seam at a depth of 780 feet. The banking arrangements at the surface are described in Mr. C. Liddells paper. The screening-plant is an exact duplicate of the plant already described.

The winding-engine fitted with Cornish double-beat drop-valves and trip-gear, has two cylinders, 28 inches in diameter by 6 feet stroke, and the drum is 16 feet in diameter. Steam is supplied at a pressure of 100 pounds per square inch.

A jack-engine, placed immediately between the two shafts, has two cylinders, 16 inches in diameter by 26 inches stroke, and the drum, 10 feet in diameter, is geared 3 to 1 on the second-motion shaft.

Pumping-plant. — A double-acting duplex condensing pumping-engine is temporarily fixed in the Main seam and forces the water to bank from a depth of 500 feet. It has two steam-cylinders, 20 inches in diameter by 2 feet stroke, working two rams, 9 inches in diameter. Should one side of this engine need repairs, the other side may be worked independently, and so maintain a partial delivery. It is capable of delivering 33,000 gallons per hour.

A Cornish direct-acting steam-pump, with cylinders 8 inches in diameter by 12 inches stroke, fitted with a suction-condenser, deals with the feeders lying below the Main seam.

The permanent pumping-plant, in course of erection, will be worked by electric motors. The main generator is of the six-pole continuous-current compound type, developing 300 amperes at 500 volts when running at 500 revolutions per minute. The compound engine, driving the generator, has a high-pressure cylinder, 15¾ inches in diameter, and a low-pressure, 25 inches in diameter, with a stroke of 33 inches, and the flywheel, 14 feet in diameter, is grooved for 10 ropes, 1½ inches in diameter. The main cables are carried down the downcast-shaft to the Yard seam, where the main pumps are fixed.

The main pumps comprise: A three-throw horizontal pump with rams, 10 inches in diameter by 15 inches stroke and when running at 33 revolutions per minute, it is capable of delivering 400 gallons per minute against a head of 576 feet. This pump is driven by a shunt-wound, constant-speed continuous-current motor of 100 horsepower at 470 volts when running at 550 revolutions per minute.

Another three-throw horizontal pump, with rams 7 inches in diameter and 9 inches stroke, fixed in the Low Main seam, when running at 42 revolutions per minute, is capable of pumping 150 gallons per minute against a head of 315 feet and delivering into the Yard seam. This pump is driven by a multi-polar protected motor of 25 horsepower at 470 volts, when running at 750 revolutions per minute.

There are also two three-throw pumps, with rams, 6 inches in diameter by 9 inches stroke, fixed in the face of the dip-workings of two different districts in the Yard seam each capable of pumping 100 gallons per minute against a head of 100 feet, when running at 40 revolutions per minute. The motors for driving these pumps are of the multi-polar type yielding 11½ horsepower at 450 volts, when running at 970 revolutions per minute.

Electric Lighting. — A Tyne compound-wound continuous-current dynamo, developing 240 amperes at 105 volts when running at 670 revolutions per minute, is capable of running 400 lamps of 16 candlepower. This dynamo is run by an engine with two cylinders, each 11¾ inches in diameter by 24 inches stroke, at 120 revolutions per minute.

Ventilation. — A Capell fan, 16 feet in diameter by 5 feet wide, is capable of exhausting 200,000 cubic feet of air per minute at 2½ inches water-range when running at 168 revolutions per minute. The fan is driven by an engine, with a cylinder, 16¾ inches in diameter by 3 feet stroke, and a flywheel, 12 feet in diameter, running at 84 revolutions per minute.

Compressed-air Plant. — A compressor with air-cylinders, and steam-cylinders, 22 inches in diameter by 4 feet stroke, supplies compressed air for driving dip-pumping and coal-cutting machinery.

Haulage. — The haulage is effected by endless ropes running above the tubs and attached by means of forks. The engine, situated on the surface, has two cylinders, 14 inches in diameter by 20 inches stroke, geared 10 to 1, and is supplied with steam at a pressure of 80 pounds per square inch. The Cadzow driving-pulley, 7½ feet in diameter, is fixed on the third-motion shaft. The main driving-rope passes down the downcast-shaft and round clutch-pulleys, erected on the shaft-sidings, by which means the haulage-rope in any district may be stopped without stopping the driving-engine. A drum, fixed on the second-motion shaft of this engine, when the driving-pulley is out of gear, enables the engine to be used as a jack-engine for the downcast-shaft.

Winches. — For pump and shaft work, there are :— Three steam-winches with cylinders 8 inches in diameter by 12 inches stroke, and double purchase drums 21 inches in diameter by 29 inches wide ; also a capstan or crab-engine with two cylinders, 12 inches in diameter by 20 inches stroke, and a drum 4 feet in diameter geared 25 to 1 on the third-motion shaft.

Boilers. — The boiler-shed extends the entire distance between the two winding-engines and contains nine Lancashire boilers, 30 feet long and 7½ feet in diameter, three of these work at a pressure of 80 pounds, and six at a pressure of 100 pounds per square inch ; and all are fitted with Meldrum forced-draught furnaces for burning duff-coal.