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In front, this bent end is bolted to the flange of the front strengthening plate. In rear the bent portion is longer, and terminated at top by another bend, which serves as a point of application for a lever on a wheel, when running to and from battery. The trunnion-plates fit over the top ends of the strengthening plates, which meet around the bed, and are fastened to the flanges of the latter by movable bolts and nuts.
The cheeks are joined together by transoms made of bar-iron. They are parallel to each other, and in order that the base ring on the gun may not interfere with giving it the full elevation by striking against them, it is proposed to dispense with the base ring in sea-coast and garrison pieces, and to retain the preponderance by reducing the swell of the muzzle.
The front of the carriage is mounted on an axle-tree, with truck wheels similar to the wooden casemate carriages.
70. Describe the chassis.
It consists of two rails of wrought iron, the cross section of each being in form of a T, the flat surface on top being for the reception of the shoe-rail of the gun-carriage. The rails are parallel to each other, and connected by iron transoms and braces. The chassis is supported on traverse-wheels.
A prop is placed under the middle transom of the chassis, to provide against sagging.
71. What carriage is used for conveying ammunition for a field battery?
The CAISSON.
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