The results of the explosion.
The equivalent of 850 pounds of T. N. T. is estimated to have exploded in and upon the Cassin's fantail; this includes the charges of the torpedo and of both depth mines. No. 4 gun, blown overboard, left the ship to port, although that was the side which the torpedo hit. The gun went over at a point well forward of her mount. The mass of the wreckage, however, went to starboard. Explosion of the depth charges, rather than that of the torpedo outward or in throwback, supposedly effected this. About five seconds elapsed between the torpedo's detonation and those of the mines. They probably went off close together, for accounts vary as to whether there were in all two or three explosions.
The bulkhead buckles.
Of the two after doors, that to port threatened to carry away soon after the seas began to pound in. The main mass of the wreckage which dropped off did so upward of an hour after the explosions. It was at this time that the bulkhead began to buckle and the port door and dogging weaken. It was shored with mattresses under the personal direction of the executive. Up to this time and until the seas began to crumple the bulkhead completely, there was only a few inches of water in the two P. O. compartments; and even when the Cassin reached Queenstown, hardly more than three feet. None of the compartments directly under these three on the deck below—handling room, magazine, and oil tanks—were injured at all. The tanks were farthest aft, and were pumped out after docking.
Freaks of flying metal.
One piece of metal entered the wash room and before coming to rest completely circled it without touching a man who was standing in the center of the compartment. Another stray piece tore a six-inch hole in one of the stacks.
The destroyer within signal distance at the time of the attack was the U. S. S. Porter. It is believed that she saw the explosion, at least of the two depth charges, and thinking that the Cassin was attacking a submarine, started off scouting before a signal could be sent and after the radio was out of commission.
The Alcedo's last voyage.
Low visibility hides convoy.
At 4 p. m., November 4, 1917, the U. S. S. Alcedo proceeded to sea from Quiberon Bay on escort duty to take convoy through the war zone. Following the northbound convoy for Brest, when north of Belle Ile formation was taken with the Alcedo on the starboard flank. At 5.45 p. m. the Alcedo took departure from Point Poulins Light. Darkness had fallen and owing to a haze visibility was poor, at times the convoy not being visible. About 11.30 visibility was such that the convoy was seen on the port bow of the Alcedo, the nearest ship, according to the commanding officer's estimate, being about 1,200 yards distant. Having written his night order, the commanding officer left the bridge and turned in.