MARK 10 AND MARK 10 MOD. 1 GUN MOUNTS
These two mounts are of the Fixed Height Type similar to Mark 5 Mounts, except for the stands. The difference between Mark 10 and Mark 10 Mod. 1 Mounts is in the design of the stand and is explained in greater detail later. Mark 10 Mount is illustrated in Figure 53. Mark 7 or Mark 7 Mod. 1 stands, Mark 7 carriage and Mark 5 cradles are used on these mounts.
The gun can be elevated between 15 degrees below horizontal (depression) and 90 degrees above horizontal the same as Mark 6 Mount. The gun and its cradle can be locked in either the 5 degree or 90 degree above horizontal positions by the cradle lock built in the right side of the carriage. When the mount is installed within splinter bulwarks, carriage extension screws (299946-4) described on page 88 and illustrated in Figure 29 may be used to limit the gun's depression to 3 1/2 degrees.
PEDESTAL MARK 7 AND MARK 7 MOD. 1 AND PIVOT
The two pedestals Mark 7 and Mark 7 Mod. 1 are of the tripod type hut differ in manufacturing details. They are made up of a number of steel stampings or rolled shapes and plates welded together. The stand legs on Mark 7 stand are "T" shaped and are 2 inches shorter than the "U" shaped legs used on Mark 7 Mod. 1 stand. These legs are welded at one end to the stand sleeve and at the other end to the base. The base is provided with a number of foot holds for the gunner's convenience.
The pivot housing used on Mark 7 stand is 19 1/8 inches long or 2 inches longer than the one used on Mark 7 Mod. 1 stand. The pivot housing is held stationary in the stand by a draw bolt fitted with a lock washer and nut. The upper end of the housing is threaded for a retainer, the same type as used on Mark 5 Mounts. The same retainer lock screw is also used. The steel cap and gasket secured to the lower end of the pivot housing have four bolt holes on the Mark 7 stand and six bolt holes on the Mark 7 Mod. 1 stand. These caps are fitted with a pipe plug. The plug should be removed when the mount is installed on a submarine.
The pivot is similar to that used on Mark 5 Mounts except that it is hollow and is lubricated with grease instead of oil. A grease fitting located in the top provides lubrication to the two babbitt faced thrust bearings used above and below the pivot flange. The thrust bearings are the same as used on Mark 5 Mounts. Circumferential grooves are provided in the upper and lower pivot radial bearings. These bearings are lubricated by two grease fittings in the stand. One is located near the upper end of the pivot housing and the other fitting is near the lower end of the stand sleeve.
CARRIAGE MARK 7
The arms extending rearward on the carriage are the same length as those on Mark 6 carriage. The base of the carriage is similar to that on Mark 5 carriage, except that the boss for the carriage lock is located slightly to the left of the centerline instead of being on the centerline as on the Mark 5 carriage.
This lock is the same as used on Mark 6 Mount and described on page 83.
CRADLE MARK 5
The cradle is the same type as used on Mark 6 Mounts. See Page 81 for description and operation.
The cradle lock is the same type as used on Mark 6 Mounts. See page 83 for description and operation.