Professional Papers on Indian Engineering Volume 4 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1867 Excerpt: ...apparatus then comes into action. VOL. IV. 2 F An air-tight cylinder, or "bell," as it is technically called, of wrongLtiron, 7 feet in diameter, 9 feet long, and weighing upwards of nine tons, is fixed on to a length of the cast-iron cylinder pier to be sunk. The "bell" is a cylinder fitted with a wrought-iron cover securely bolted to it. Through this cover two cast-iron chambers, called "air-locks," project 2J feet above the top of the cylinder, and 3 feet 9 inches below the cover: they are D shaped, in plan, with a sectional area of about 6 square feet. The top of each air-lock is provided with a circular opening, 2 feet in diameter, and with a flap, working on a horizontal hinge, that serves to close it air-tight when the chamber is filled with compressed air. The communication from the chamber to the inside of the cylinder is made through a rectangular opening, 2 feet by 3 feet 4 inches on the flat side of the chamber, and has an iron door, working on vertical hinges, to close it air-tight, when required. The flap is analogous in its use to the lower gate of a canal lock, and the door answers a purpose corresponding to that of the upper gate. These air-locks are placed upon opposite ends of the same diameter of the cylinder, and the lock doors open so as to communicate with opposite semi-cylinders. Two light wrought-iron cranes are fixed inside the cylinder, the jibs of which sweep over the space between the air-locks, and extend into the chambers when the doors are open; Bo that a loaded bucket suspended from the crane may be deposited in the chamber, with the least amount of labor. A chain passes over the sheaves of these cranes, and round the barrel of a windlass, worked by two handles in the ordinary way; and carries a...