Fighting A Depth Bomb

: Winning A Cause World War Stories

All who have read of the sinking of the Lusitania, by a torpedo, shot

from a German U-boat, realize the terribly destructive force of this

modern weapon of war, but many do not know that the depth bomb is even

more destructive and must be handled with much greater care to be sure

that it does not explode accidentally or prematurely. The bomb usually

contains from 100 to 500 pounds of tri-nitro-toluol, or T.N.T., as it

is usually called, the most powerful of all explosives. The explosion

of a ship loaded with it in Halifax harbor, December 6, 1917, caused

almost as great a loss of life and property as a volcanic eruption.

When the 500 pounds of T.N.T. is exploded it changes suddenly into

nearly 80,000 cubic feet of gas. Now this amount of gas will fill a

room 160 feet long, 25 feet wide, and 20 feet high. When the bomb

explodes under the water the gas must find room somewhere, and with

tremendous force it pushes the water in all directions. If a hollow

submarine is near the point of the explosion, its walls will give way

easier than the water around it and it is crushed like an empty egg


Only very swift boats should drop the depth bombs from their sterns,

for the boat must be moving at a rate of at least twenty-five miles an

hour to be sure to escape damage from the bombs dropped behind her.

John Mackenzie, the hero of this story, writes in regard to the

converted yachts used for dropping depth bombs in European waters as

follows: Only destroyers made speed exceeding 25 knots. There were no

converted yachts operating in European waters capable of making 25

knots. A very few made 15 to 18 and the majority about 12. Of course

we had to take our chances in getting away safely, although we knew

that the chances were about even. That is, we were in about as much

danger from our depth charges as the enemy was. His statement shows

the risks that American sailors were willing to take.

The bomb, of course, weighs over one hundred pounds. It is made with

one end flattened, upon which it will stand, and in the early types its

accidental discharge is rendered practically impossible by a sort of

peg called a safety pin, which must be removed before the bomb is

dropped. The use of depth bombs against the U-boats made fighting in

the German submarines so dangerous and so much to be dreaded, that it

is said, as the war drew to a close, all U-boat crews had to be forced

into service, and that none of them expected ever to return and see

their homes and friends again.

In the early days of the war the bombs were carried in cradles, and

later in racks or run-ways. From most of the bombs the detonator,

which would fire them, was removed; but some were kept ready for

instant firing, near the stern of the ship. The early type of bomb was

discharged by a length of wire attached to a float. The bomb itself

sank, the float remained on the surface of the water and reeled off the

wire until the pull upon it discharged the bomb. It can be readily

seen that the depth at which the bomb was discharged would depend upon

the length of wire attached to the float. Imagine what might follow if

one of these bombs, set ready for discharge, should break loose from

its case in a storm at sea.

Such a terrible accident did happen on the U.S.S. Remlik. The ship was

groaning and tossing in a very heavy sea, for a severe storm was

raging. She gave a lurch and pitched back with so much force that a

wooden box, containing a depth bomb and securely fastened to the after

deck, suddenly broke. The bomb rolled out of the box and began to

bound back and forth across the deck as the ship lurched and pitched

from side to side.

The crew seemed stunned, and no orders were issued for concerted

action. The frightfulness of the situation was greatly increased when

it was observed that the safety pin had dropped out. All expected the

next time the bomb struck with force against the rail that the float

section would be released and reel off enough wire to fire the

detonator and utterly destroy the ship and all aboard.

But Chief Boatswain's Mate, John Mackenzie of the Naval Reserve Fleet,

needed no orders. He saw what should be done and did not wait for some

one to order him to do it. He could not pick up the bomb in his arms

and throw it overboard, for it weighed too much, and even if he could

this might be the worst thing to do. The ship was laboring and barely

holding her own with no headway, although the engines were turning over

for 8 knots, and the bomb would no doubt have exploded directly under

the ship had it gone overboard.

Mackenzie had a plan, and the first step in it was to stop the bomb.

He threw himself in front of it and tried to hold it by his arms and

the weight of his body, but the weight and the momentum of the moving

bomb were too great and he was pushed aside; but he had stopped its

movement somewhat so that when it struck the rail on the other side of

the deck it did not explode. He jumped for it as it bounded back from

the rail and almost stopped it, but it seemed to those looking on that

the hundreds of pounds of metal and explosives would roll over his body

and seriously injure him. He escaped this, however, and slowed down

the movement of the heavy bomb to such an extent that near the opposite

rail he was able to grasp it, lying with feet and hands braced in the

grating of the gun platform. Then to be sure that it did not escape

him until help came, he turned it upright upon its flattened end and

sat down upon the most destructive bomb used in war, on the deck, of a

ship lurching at sea in a severe storm.

Then other members of the crew that had been watching him as if dazed

ran to his assistance, and the bomb was soon placed in safety.

The commanding officer of the Remlik recommended that Chief

Boatswain's Mate, John Mackenzie, be awarded the Medal of Honor. The

report to the Secretary of the Navy was in part as follows:--

Mackenzie in acting as he did, exposed his life and prevented a

serious accident to the ship and the probable loss of the ship and the

entire crew. Had this depth charge exploded on the quarterdeck, with

the sea and the wind that existed at the time, there is no doubt that

the ship would have been lost.

Mackenzie was awarded by the Navy Department the Medal of Honor, and a

gratuity of one hundred dollars; but these awards are of little value

compared with the greater reward which comes to him in the admiration

and respect of all who read or hear the story of his heroic deed.