Six-Inch Ribbed Cavity Armor-Piercing Shell
Projectile was loaded with two pounds of black charcoal powder and fused with magazine fuse. Fired at six-inch Krupp hard-faced armor plate. Shell burst about eight feet to rear of plate after penetrating the same. Weight of largest fragment recovered 101⁄4 pounds. Average weight of fragments, 25⁄16 ounces. Total number of pieces recovered, 650.
Courtesy of the Bethlehem Steel Co.
Ammunition. (See [page 402].)
Made-up ammunition, with brass cartridge cases, and cast-iron and forged steel shells and armor-piercing projectiles. The rounds shown are as follows: Rounds with forged steel shell for one-pounder gun, for three-pounder gun and for six-pounder gun respectively; round with cast-iron shell for three-inch field gun; round with capped armor-piercing shell for three-inch fifty-caliber rapid-fire gun; round with forged steel shell for four-inch forty caliber rapid-fire gun; round with capped armor-piercing projectiles for the four-inch and twelve-centimeter fifty-caliber rapid-fire guns respectively, and round with forged shell for six-inch gun.
Two-Handed Elevating Gear. (See [page 402].)
Method of obtaining a variable movement of a miniature target, corresponding to rolls of a vessel of from 1 to 10 degrees. A series of 25,000 shots were fired thus, by eight gun pointers, at targets corresponding to the size of a battleship as seen at ranges of 1,500, 3,000, 6,000 and 9,000 yards. Using a sub-caliber rifle rigidly attached to the muzzle of the gun and fired electrically by the firing gear of the big gun. The record shows that under circumstances of average difficulty at sea (say 5 degrees roll and range of 3,500 yards), the gain in accuracy (increase in hits with a given expenditure of ammunition) is about 25 per cent, and the gain in speed of hitting (number of hits in a given time) is 50 per cent, with the two-hand gear as compared with the usual one-hand gear.
Range Finder and Predictor; Home and Distant Station Instruments. (See [page 403].)
Continuous readings, by means of automatic indicators, of either the actual or the predicted ranges and azimuths of moving target at every instant and for any distance from 1,000 to 15,000 yards and through an azimuth of 160 degrees, are clearly presented at all times. The ranges are read in scales of 10-yard steps, and the azimuths for each .01 degree are traversed. The corrected ranges for the various guns served by the instruments, either actual or automatically predicted for any interval of time, are constantly communicated to the various guns whose fire is being directed by the observation instrument.