for cleaning
out the bilges and for the purpose of saving weight. The upper edges of
these holes are about a foot from the roof of their compartments; so there
could be a considerable volume of gas trapped there if necessary. And if
you pumped in too much it wouldn't go to waste, it would simply bubble
into the next piece of the egg box and be trapped there.
"After the bilges," Dickson went on, "there are the storage spaces and
ballast tanks on each side of Numbers One, Four, and Seven. Some of these
are likely to be more watertight than others, so I would have to point
out their exact position to you. This would mean lugging me over a pile
of cargo, and maybe shifting some of it; therefore, the coffer dams and
intercostal spaces would be less trouble to begin with."
When he had stopped speaking Wallis took Dickson's flashlamp from him
and directed the beam around the walls of the tank. He said, "You've
been very helpful, Mr. Dickson, but I'm afraid we'll have to modify
your order of priority. The for'ard coffer dam is too badly damaged by
the torpedo which hit the forepeak. I don't approve your second idea,
for two reasons. One, because the air-filled spaces in the ship are all
well below the weather deck, so that we must already be in a dangerously
top-heavy condition and an increase of buoyancy at keel level could very
easily roll us over. The tanks would remain watertight if this were to
happen, but the odd pockets of air trapped about the ship would spill
out and our rate of descent would increase. Two, the gas trapped in the
intercostals would be constantly forced upwards by water pressure so that
there would be the danger of contaminating our air with acetylene. This
poison gas would be right under our feet. It is very difficult to spot
and seal off a gas leak compared to one of water, and if our aiir was
contaminated there is no way of replacing it.
"That is why we'll use the aft coffer dam first," Wallis continued. "The
gas will be injected as low as possible, will bubble to the top, and there
will always be a water seal to keep the acetylene from getting back to us.
"But in case the dam isn't airtight up top or it doesn't give a sufficient
increase of buoyancy," he added, "maybe you could point out a few likely
compartments here in Seven. The doctor will mark the places with chalk
while I start looking for the hardware we'll need."
He stopped abruptly. The tank around them was reverberating to the sounds
of frantic banging, the sounds a heavy spanner might make against a metal
deck. And above the noise, growing louder and more piercing with each
second that passed, there was the sound of screaming. The doctor snatched
the flashlamp from Dickson's hand and hurried aft.
"It isn't Jenny," Dickson said out of the darkness, the
anxiety in his voice making it sound like a question rather
than a statement. "It must be the other girl. . . ."
VII
Wallis moved carefully towards the starboard wall of the tank until the
workbench there stopped him, then groped around the top of it until he
found the spare lamp. He spent a longer time finding a place to prop it so
that its beam would illuminate a useful area of bench, but after that he
did not waste any time at all because he had spent most of the previous
night thinking about what he had to do and the material available for
doing it.
From the sick bay in Eleven the sounds made by the Murray girl continued
to reach them, quieter now and interspersed with the gruffer, reassuring
noises made by the doctor and the low voice of Miss Wellman backing him
up. Jenny might just as easily have joined the other girl in screaming
her head off instead of helping the doctor calm her down, but she
hadn't. Wallis thought that he approved of Miss Wellman.
"When you were moving the light around," Dickson said suddenly, "I couldn't
help noticing that. . . that . . ." He stopped, then finished helplessly,
"What on earth have you been doing
out the bilges and for the purpose of saving weight. The upper edges of
these holes are about a foot from the roof of their compartments; so there
could be a considerable volume of gas trapped there if necessary. And if
you pumped in too much it wouldn't go to waste, it would simply bubble
into the next piece of the egg box and be trapped there.
"After the bilges," Dickson went on, "there are the storage spaces and
ballast tanks on each side of Numbers One, Four, and Seven. Some of these
are likely to be more watertight than others, so I would have to point
out their exact position to you. This would mean lugging me over a pile
of cargo, and maybe shifting some of it; therefore, the coffer dams and
intercostal spaces would be less trouble to begin with."
When he had stopped speaking Wallis took Dickson's flashlamp from him
and directed the beam around the walls of the tank. He said, "You've
been very helpful, Mr. Dickson, but I'm afraid we'll have to modify
your order of priority. The for'ard coffer dam is too badly damaged by
the torpedo which hit the forepeak. I don't approve your second idea,
for two reasons. One, because the air-filled spaces in the ship are all
well below the weather deck, so that we must already be in a dangerously
top-heavy condition and an increase of buoyancy at keel level could very
easily roll us over. The tanks would remain watertight if this were to
happen, but the odd pockets of air trapped about the ship would spill
out and our rate of descent would increase. Two, the gas trapped in the
intercostals would be constantly forced upwards by water pressure so that
there would be the danger of contaminating our air with acetylene. This
poison gas would be right under our feet. It is very difficult to spot
and seal off a gas leak compared to one of water, and if our aiir was
contaminated there is no way of replacing it.
"That is why we'll use the aft coffer dam first," Wallis continued. "The
gas will be injected as low as possible, will bubble to the top, and there
will always be a water seal to keep the acetylene from getting back to us.
"But in case the dam isn't airtight up top or it doesn't give a sufficient
increase of buoyancy," he added, "maybe you could point out a few likely
compartments here in Seven. The doctor will mark the places with chalk
while I start looking for the hardware we'll need."
He stopped abruptly. The tank around them was reverberating to the sounds
of frantic banging, the sounds a heavy spanner might make against a metal
deck. And above the noise, growing louder and more piercing with each
second that passed, there was the sound of screaming. The doctor snatched
the flashlamp from Dickson's hand and hurried aft.
"It isn't Jenny," Dickson said out of the darkness, the
anxiety in his voice making it sound like a question rather
than a statement. "It must be the other girl. . . ."
VII
Wallis moved carefully towards the starboard wall of the tank until the
workbench there stopped him, then groped around the top of it until he
found the spare lamp. He spent a longer time finding a place to prop it so
that its beam would illuminate a useful area of bench, but after that he
did not waste any time at all because he had spent most of the previous
night thinking about what he had to do and the material available for
doing it.
From the sick bay in Eleven the sounds made by the Murray girl continued
to reach them, quieter now and interspersed with the gruffer, reassuring
noises made by the doctor and the low voice of Miss Wellman backing him
up. Jenny might just as easily have joined the other girl in screaming
her head off instead of helping the doctor calm her down, but she
hadn't. Wallis thought that he approved of Miss Wellman.
"When you were moving the light around," Dickson said suddenly, "I couldn't
help noticing that. . . that . . ." He stopped, then finished helplessly,
"What on earth have you been doing