3rd Experiment.
Torpedo:—33 lbs. of granulated gun-cotton, saturated with water; total weight of charge being about 41 lbs. It was enclosed in a 1/4" iron case, 12-1/2" × 12" × 12-1/2", the primer being 2-1/2 lbs. of slab gun-cotton, included in the 33 lbs. It was placed at 4' actual distance from the target, measuring from the centre of the case, and opposite No. 30-1/2 solid frame on the starboard side; 9-1/4' below the surface of the water.
Effect of explosion:—Outer bottom blown in from upper edge of the lower longitudinal to the lower edge of the upper longitudinal between Nos. 28 and 32 frames; an area of 18 × 11 feet. The butts of the flat keel were started and the plating broken across No. 30-1/2 frame from the flat keel plate to the upper deck. Shelf plate at Nos. 30-1/2 and 32-1/2 frames was broken. Nos. 29, 30, and 31 frames were blown in from first to third longitudinal; lower longitudinal from No. 28 to 31 also blown in. Two holes were blown through the inner bottom, measuring respectively 6 × 1·5' and 5' × ·25', making the total area of inner bottom destroyed 10 square feet. A steam launch with steam up and outrigger torpedo gear in place, one pole being rigged out, was placed with the stem of the boat 22' horizontally from the torpedo. She was uninjured and shipped very little water.