Torpedo:—60 lbs. of gun-cotton in slabs, saturated with water. Total weight of charge 75 lbs. It was enclosed in a 1/4" iron case with cast iron ends. It was placed at 15' actual distance from the nearest side of the case to the target, and opposite No. 4 frame on the port side, 10' below the surface of the water.
Effect of the explosion:—The effect upon the vessel was unappreciable. This charge represented the large Whitehead fish torpedo, and its position corresponded to that of this torpedo when striking a net at a small angle with the keel.
2nd Experiment.
Torpedo:—The Harvey towing torpedo, charged with 66 lbs. of gunpowder, primed with gunpowder, and fired by means of an electric fuze. It was placed at 3' actual distance from the target, measuring from the centre of the torpedo, and opposite No. 4 solid frame on the starboard side, the vertical axis of the torpedo being at right angles to the vessel's side, 9-1/4' below the surface of the water.
Effect of explosion:—This and the two following torpedoes were fired simultaneously. The outer bottom was blown in from the upper edge of the flat keel plate to the underside of the water-tight longitudinal, and fore and aft from No. 2 to No. 6 frames; an area 16' × 8-5/6'. Flat keel plates were broken between No. 2 and No. 4 frames, and the 4th strake of the bottom plating was broken, and the frames for that space blown in. Two holes were blown through the inner bottom, measuring respectively 2' × 2' and 7' × 1', making the total area of the inner bottom destroyed, 11 square feet.
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.
4th Experiment.
Torpedo:—31 lbs. 14 oz. of gun-cotton in slabs, saturated with water, total weight about 40 lbs. It was enclosed in a 1/4" iron case 12-1/2" × 12-1/2" × 6"; primer being 20 oz. of gun-cotton, included in the 31 lbs. 14 oz. 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 port side; 9-1/4' below the surface of the water.