The valves were flung open and the compressed air escaped hissing from the tanks. At the same time a gigantic, intermittent snorting ensued, like the blowing and belching of some prehistoric monster. There was an uncomfortable pressure in our ears, then the noise became more regular, followed by a buzzing and a shrill hum. All the high notes of the engines in the central station intermingled and made a bewildering noise. It was like a mad diabolical singsong. And yet it was almost like silence after the dull, heavy pounding of the oil-motors--only more insistent and irritating. The penetrating hum in the various vents announced the fact that the diving mechanism was in operation. It moaned and sang lower and lower in the scale of tones. These slowly diminishing and steadily deepening tones give one the physical feeling of mighty volumes of water pouring in and flooding full.
You have the sensation of growing heavier and sinking as the boat grows heavier and sinks, even though you may not be able to see through the turret window, or the periscope, how the bows are gradually submerged and the water climbs higher and higher up the turret until all things without are wrapped in the eerie twilight of the depths.
The faithful lamps burned, however, and then a real silence suddenly ensued. There was no sound but the gentle trembling rhythm of the electric engines.
I then gave the order:
"Submerge to twenty meters!"
"Both engines half steam ahead!"
I was able to follow our submersion by means of the manometer. Through flooding the tanks, the boat is given several tons over-weight and the enclosed ship's space is made heavier than the displaced quantity of water. The titanic fish, therefore, began to sink downward in its element, that is to say, it began, in a certain sense, to fall. At the same time the electric engines are put into motion and the propulsive force of the propellers acts upon the diving rudders and causes the sinking to become a gliding. After the required depth has been reached--something which may easily be read from the manometer that records the depth--all further sinking may be stopped by simply lightening the hull, which is done by forcing out some of the water in the submarine's tanks. The furious growling of the pump is always a sure sign that the required depth is being approached. The noise ceased, only the electric motors continued to purr, and the word came from the central station:
"Twenty meters--even keel!"
"Rudder set!"
So we forged ahead at a depth of twenty meters. Of course we are "blind" under such conditions and can regulate our movements only by means of the depth recorder and that precious little jewel of the boat, our compass. No ray of light reached us any longer from without, the periscope was submerged long ago and the steel safety covers over the windows were closed. We had been metamorphosed completely into a fish.[1]
[Footnote 1: ©]
Orders were then given to rise again. The Deutschland carried out this manoeuvre with the same facility with which she had taken the initial dive of her long voyage. In record time the ballast tanks were emptied and the change from electric motors to oil engines was completed without further loss of time. The boat was started at top surface speed towards her ultimate goal, the United States.
On the following day the Deutschland barely escaped running foul of a British submarine chaser, disguised as a neutral merchantman. A quick dive alone saved her. When she came up again a wild storm and a heavy sea were raging. Even before the change from the electric motors to the oil engines had been completed, another dangerous looking vessel appeared and before long was recognized as a hostile destroyer by Captain König. He tells us that he "Made one jump into the turret and slammed the cover fast."
"Alarm! Dive quickly! Flood!"
"Set diving rudder!"
"Twenty meters' depth!"
The commands were uttered in almost one breath. But the execution of them!
To attempt to dive with such a sea running was sheer madness, as experience has taught us. What was I to do? The destroyer might have seen us already!
Well, we knew we must get under--and as quickly as possible.
The men in the central below me were working away in silent haste. All the exhausts were opened wide, the compressed air hissed from the tanks--the diving vents were chanting in all possible keys.
I stood with my lips pressed together and stared out of the turret window upon the tossing sea, and watched for the first sign of our going down. But our deck remained still visible and we were continually lifted into the air by some wave. There was not a moment to be lost.
I ordered the diving rudder to be set still more sharply and both engines to drive ahead with full power.
