The Y-3 was now making ten knots, for, as Captain Nicholson said, "there was no use wasting time and giving the enemy time to plant a barrier."
Still five hundred yards from the sandbar which must be crossed, there was a jar, a moaning, grinding sound, and the motors went instantly dead. From the battery compartment there was a rush of water into the living quarters.
It was but the work of a moment for the crew to "dog down" the doors of that compartment to segregate the damage and prevent the flooding of other compartments. But even then, the Y-3 was in a bad way, and all on board realized it.
"I guess we are gone this time," said Frank quietly to Jack.
"Looks like it," was Jack's cool reply. "However, while there is life there is hope."
Captain Nicholson noticed the look of anxiety on the lads' faces.
"Don't you worry," he said cheerily. "We'll get out of here yet."
But now the deadliest foe of the submarine was at work—chlorine gas. The action of the salt water on the sulphuric acid of the battery cells was generating it with fatal quickness. Already the boys could feel a deadly burning sensation in their throats and noses.
Fifteen minutes of that atmosphere would have left all on board the submarine gasping and stifling sixty feet below the fresh air that meant life. There was but one thing to do—come to the surface and run for it in the face of the fort.
Captain Nicholson realized that it would be the end if the upper exhaust of No. 3 cylinder failed now, for with the electric engines gone, running on the surface with the Diesels was the only hope. He acted on the instant.