The Deadly Tank
The Sky Wagon droned smoothly through a series of figure eights as Rick
and Scotty inspected every inch of Clipper Cay and its surrounding
waters. While Rick flew, Scotty marked off landmarks on the chart of the
island that Dr. Ernst had provided.
"I wish we could spot the wreck of the _Maiden Hand_," Scotty remarked.
"Too deep," Rick said. "We can't see bottom at twenty fathoms even in
water as clear as this."
"I've got everything important marked. What say we land and look over
our property?"
"Okay. I'll shoot the beach while you look for coral heads. We don't
want to snag a pontoon."
The boys had already identified their house. It was set at the edge of
the palms, about fifty yards inland from the beach. It looked fine.
There was a small dock to which the _Water Witch_ could be tied up when
the scientists arrived.
Rick estimated that Tony and Zircon would arrive about sundown, two
hours hence. The boys had flown over the _Water Witch_ en route from St.
Thomas. Apparently the scientists were enjoying the trip. Zircon had
been sprawled in the cockpit while Tony trolled for fish.
"I'm a little surprised there wasn't something wrong with the plane,"
Rick observed. He and Scotty had gone over the Sky Wagon from propeller
hub to rudder, fearful that the unknown enemy might have sabotaged the
plane. But there was no sign of any tampering. However, the inspection
had taken so long that it was late afternoon before they got away. It
was significant and perhaps a little ominous that Steve and Jimmy Kelly
had assigned a pair of husky Shore Patrol men with .45-caliber sidearms
to stay with them until the plane actually took off.
"Maybe the two men who came after us were acting without orders," Scotty
replied. "Maybe the real brains of the gang aren't even interested in
us."
"I hope that you're right. See any coral heads?"
Although most coral growth was limited to the reef area, outcroppings of
coral called "heads" had grown up toward the surface in some places.
There were none in the stretch of water before the beach house where
Rick planned to land.
"The water's clear. Pick your direction. There's not enough wind to make
any difference."
"I'll land parallel to the beach."
Rick turned south down the center of the island. When he had reached the
right position he cut the throttle, and the nose of the Sky Wagon
dropped. He banked tightly, reversing course, until the plane was headed
north a hundred yards out from the beach. He let the plane feel its way
toward the water, then felt the first bump as the pontoons touched. In a
moment they were down, and Rick swung the plane to taxi in toward their
new home.
Scotty was already stripping off his shoes and socks. As the pontoons
touched bottom a few yards from shore, Scotty climbed out. Rick cut the
gun while his pal pulled the plane up on the beach.
Rick got out and waited until Scotty slipped his shoes on again, then
they walked to the cottage.
The door was unlocked. Few people came to Clipper Cay, and locks weren't
considered necessary. The boys pushed open the front door and walked in.
There was a large living room and three bedrooms, each with twin beds.
In the rear of the cottage was a kitchen with kerosene stove and
kerosene refrigerator. A fifty-gallon drum out back provided the fuel
supply, which was piped in through copper tubing. Rick checked the fuel.
The tank was full. He read the simple instructions tacked to the wall
over the refrigerator, then lighted the burner. There were frozen foods
and soft drinks as well as dairy products among their supplies, packed
in dry ice in the _Water Witch's_ food locker; the refrigerator would be
cold enough for the supplies by the time the boat arrived.
For bathing in fresh water there was an outdoor shower, a shower head
rigged to a five-gallon drum and supported on a frame of two-by-four
wooden members. A canvas curtain gave privacy. Other sanitary facilities
were equally primitive but effective.
Scotty opened the door of a lean-to shed on the rear of the house. "We
can stow our diving gear in here. There's a bench, too. Looks as though
the owner used the place for cleaning fish and stowing his fishing
equipment."
They walked around to the front of the house where there was a small
porch. A few wicker chairs were upended against the wall. The boys
righted them and sat down.
"This is the life," Rick observed. "Look at that view."
They looked from the porch down to the sandy beach, past the pier and
the Sky Wagon to water that was almost glassy calm. The water continued
in a smooth stretch for about five hundred yards out to the reef. Light
breakers foamed along the reef, and beyond, the water was a blue waste
to the horizon. A quarter mile south, a break in the reef marked a
passage where boats could enter.
Somewhere, out beyond the reef, was the wreck of the _Maiden Hand_. In
his mind, Rick planned how they would go about finding it. The first
step was to rig some kind of underwater towing boards. Then he and
Scotty, equipped with their aqualungs, would be towed behind the _Water
Witch_, scanning the bottom as they went.
He wasn't worried about finding material for the towing boards. Any kind
of planks would do, or they could even make a tow board out of a fallen
log, although that would be harder to control.
"Come on," he invited. "Let's walk through the palms. We need a few
planks, and we might as well get them now."
By the time the scientists approached the pier, the boys had explored
the central part of the island and had returned to the cottage lugging
planks found in the ruin of a cottage apparently blown down by some
long-past hurricane. They dropped the planks beside the house and
hurried to catch the line that Zircon threw, then they warped the _Water
Witch_ in to the dock.
All hands turned to, and in a short time supplies were unloaded and
stored, beds were made with linen and blankets loaned by Dr. Ernst, and
the cottage began to take on an inhabited look.
While Tony Briotti began preparations for dinner, the boys carried their
aqualung equipment to the shed at the rear of the cottage and began to
check it over. Since their lives would depend on proper functioning of
the equipment, they inspected the regulators carefully, checking the
condition of the neoprene flaps. Once checked, the regulators were hung
on nails on the shed walls, out of harm's way.
The next step was to inspect the tanks. Rick had already looked them
over, but for the sake of safety the boys did it again. There were six
of them, each of seventy-cubic-feet capacity. There was an advantage to
this particular capacity at the depth where they expected to dive; a
diver could work only fifteen minutes at 120 feet without requiring
decompression, and seventy cubic feet of air would last just long
enough. Double tanks would have meant the boys would be able to stay
down nearly twice as long, but would also have meant the nuisance of
waiting through the decompression period of about thirteen minutes ten
feet below the surface on the ascent. For this reason, the boys planned
to dive with single tanks, leaving the spares on the surface.
Of course, to get even fifteen minutes of diving at twenty fathoms the
tanks had to be filled to capacity. When full, they were under enormous
internal pressure of over two thousand pounds per square inch. The tanks
had been filled at Spindrift, but the boys decided to check them again,
in case there had been some leakage through the valves during shipment.
Scotty swung one tank upright and prepared to attach the pressure gauge.
Rick, inspecting another tank for bumps that might have weakened the
tank wall, saw him do it.
For a moment Rick continued his inspection, then what he had seen
suddenly registered. He yelled, "Scotty! The valve!"
In that instant, as Scotty attached the pressure gauge, the valve blew
out!
The entire valve assembly and the pressure gauge, propelled by the
tremendous pressure in the tank, blew straight upward, ripping clear of
Scotty's hand and taking a patch of skin along. The ascending assembly,
traveling with bullet speed, clipped a lock of hair from his bent head.
[Illustration: _The valve assembly, traveling with bullet speed, barely
missed Scotty's head_]
Scotty yelled, "Run!"
The tank, its air free to escape, writhed and turned, then fell over on
its side. It was like an inflated balloon, turned loose to fly around a
room. Air jetted from it with terrific velocity, so that the tank was,
for the period while its air lasted, a true rocket.
It struck the wall of the shed and went through it like paper, smashed
into a stud and caromed slightly, so that its trajectory was altered
enough to drive it directly at Rick. He fell flat and it went over, just
grazing him, then flew into the palm grove. It hit a palm a slanting
blow and turned upward, shooting high in the air, clipping off the top
of another palm as it went.
As the boys watched, horrified, it climbed straight up. Then, its high
pressure nearly exhausted, it turned leisurely and plunged back into the
grove, almost burying itself in the sandy soil.
The boys sat down and stared weakly at each other. For the first time,
Rick noted that Scotty's hand was bleeding. He said shakily, "Here, let
me look at that."
The scientists rushed out of the house and demanded to know what had
happened. The tank had blown through its devastating course so fast that
they had not even had time to get outdoors.
Zircon bandaged Scotty's hand with supplies from the first-aid kit while
the boys told them what had happened. Tony said, "Very careless, leaving
a valve loose like that."
Rick told him positively, "It wasn't left unscrewed, Tony. We always use
a wrench on those valves because high pressure is so dangerous. And it
wasn't like that yesterday. I checked the tanks when we stowed them on
the boat."
Scotty gestured toward the other tanks. "Better take a look."
Rick did so, and gave a low whistle. The valves had all been loosened.
They were in place only by a turn or two of the threads.
"They could have come out any time," he said grimly. "Any rough handling
could have knocked a valve out. And if it had happened on the boat, the
tank would have gone right through the bottom or side. It was just luck
Scotty and I weren't killed."
Zircon wordlessly found the valve wrench and got to work screwing the
assemblies back in place. The others watched silently, until Scotty
said, "Well, at least we're out of St. Thomas. There won't be any more
sabotage!"