CHAPTER III.
GUN-CARRIAGES, GEAR, IMPLEMENTS AND EQUIPMENTS.
GUN-CARRIAGES.
207. All gun-carriages shall be constructed in exact conformity to the drawings furnished by the Bureau, and no alterations whatever will be permitted without its express sanction.
The Inspector of Ordnance will keep approved copies of all plans, and, in order to insure uniformity, will report to the Bureau any deviations from the standard drawings which he may observe in carriages received from other Yards.
The spaces required for efficient working of all guns are represented in diagrams X, Y, Z, and these, as well as the distances between pivot-centres, sizes and positions of bolts, are to be strictly adhered to.
The distance between pivot-centres of all XI-in., X-in., IX-in., and 100-pdr. carriages shall be either 142 or 117 3/4 inches, depending on the breadth of beam, position of hatches and other obstructions, and shall not be deviated from except by explicit directions of the Bureau, on a report of the particular circumstances in each case.
For the 60-pdr. Parrott, 130 inches between centres; and for the 30-pdr., 120 inches.
The sizes of sockets and pivot-bolts are established as follows: