Into a Trench
Tom cast a hasty glance over the mechanism of the machine before he
started to cross the stream by the additional aid of the grippers, or
spanners, as he sometimes called this latest device.
Along each side, in a row of sockets, were two long girders of steel,
latticed like the main supports of a bridge. They were of peculiar
triangular construction, designed to support heavy weights, and each
end was broadly flanged to prevent its sinking too deeply into the
earth on either side of a gully or a stream.
The grippers also had a sort of clawlike arrangement on either end,
working on the principle of an "orange-peel" shovel, and these claws
were designed to grip the earth to prevent slipping.
The spanners would be pulled out from their sockets on the side of the
tank by means of steel cables, which were operated from within. They
would be run out across the gap and fastened in place. The tank was
designed to travel along them to the other side of the gap, and, once
there, to pick up the girders, slip them back into place on the sides,
and the engine of war would travel on.
"You are mightily excited, Tom.
"I admit it, Ned. You see, I have not tried the grippers out except on
a small model. They worked there, but whether they will work in
practice remains to be seen. Of course, at this stage, I'm willing to
stake my all on the results, but there is always a half-question until
the final try-out under practical conditions."
"Well, we'll soon see," said one of the workmen. "Are you ready, Mr.
Swift?"
"All ready," answered Tom.
Tank A, as she was officially known, had come to a stop, as has been
said, on the very edge of Tinkle Creek. The banks were fairly solid
here, and descended precipitously to the water ten feet below. The
shores were about twenty feet apart.
"Suppose the spanners break when you're halfway over, Tom?" asked his
chum.
"I don't like to suppose anything of the sort. But if they do, we're
going down!"
"Can you get up again?"
"That remains to be seen," was the non-committal reply. "Well, here
goes, anyhow!"
Going up into the observation tower, which was only slightly raised
above the roof of the highest part of the tank, Tom gave the signal for
the motors to start. There was a trembling throughout the whole of the
vast structure. Tom threw back a lever and Ned, peering from a side
observation slot, beheld a strange sight.
Like the main arm of some great steam shovel, two long, latticed
girders of steel shot out from the sides of the tank. They gave a half
turn, as they were pulled forward by the steel ropes, so that they lay
with their broader surfaces uppermost.
Straight across the stream they were pulled, their clawlike ends coming
to a rest on the opposite bank. Then they were tightened into place by
a backward pull on the operating cables, and Tom, with a sigh of
relief, announced:
"Well, so far so good!"
"Do we go over now?" inquired Ned.
"Over the top--yes, I hope," answered Tom, with a laugh. "How about
you down there?" he called to the engine room through a telephone which
could only be used when the machinery was not in action, there being
too much noise to permit the use of any but visual signals after that.
"All right," came back the answer. "We're ready when you are."
"Then here we go!" said Tom. "Hold fast, Ned! Of course there's no real
telling what will happen, though I believe we'll come out of it alive."
"Cheerful prospect," murmured Ned.
The grippers were now in place. It only remained for the tank to propel
herself over them, pick them up on the other side of Tinkle Creek, and
proceed on her course.
Tom Swift hesitated a moment, one hand on the starting lever and the
other on the steering wheel. Then, with a glance at Ned, half whimsical
and half resolute, Tom started Tank A on what might prove to be her
last journey.
Slowly the ponderous caterpillar belts moved around on the sprocket
wheels. They ground with a clash of steel on the surface of the
spanners. So long was the tank that the forward end, or the "nose," was
halfway across the stream before the bottom part of the endless belts
gripped the latticed bridge.
"If we fall, we'll span the creek, not fall into it," murmured Ned, as
he looked from the observation slot.
"That's what I counted on," Tom said. "We'll get out, even if we do
fall."
But Tank A was not destined to fall. In another moment her entire
weight rested on the novel and transportable bridge Tom Swift had
evolved. Then, as the gripping ends of the girders sank farther into
the soil, the tank went on her way.
Slowly, at half speed, she crawled over the steel beams, making
progress over the creek and as safely above the water as though on a
regularly constructed bridge.
On and on she went. Now her entire weight was over the middle of the
temporary structures. If they were going to give way at all, it would
be at this point. But they did not give. The latticed and triangular
steel, than which there is no stronger form of construction, held up
the immense weight of Tank A, and on this novel bridge she propelled
herself across Tinkle Creek.
"Well, the worst is over," remarked Ned, as he saw the nose of the tank
project beyond the farthermost bank.
"Yes, even if they collapse now nothing much can happen," Tom answered.
"It won't be any worse than wallowing down into a trench and out again.
But I think the spanners will hold."
And hold they did! They held, giving way not a fraction of an inch,
until the tank was safely across, and then, after a little delay, due
to a jamming of one of the recovery cables, the spanners were picked
up, slid into the receiving sockets, and the great war engine was ready
to proceed again.
"Hurrah!" cried Ned. "She did it, Tom, old man!" and he clapped his
chum resoundingly on the back.
"She certainly did!" was the answer. "But you needn't knock me apart
telling me that. Go easy!"
"Bless my apple pie!" cried Mr. Damon, who was as much pleased as
either of the boys, "this is what I call great!"
"Yes, she did all that I could have hoped for," said Tom. "Now for the
next test."
"Bless my collar button! is there another?"
"Just down into a trench and out again." Tom said. "This is
comparatively simple. It's only what she'll have to do every day in
Flanders."
The tank waddled on. A duck's sidewise walk is about the only kind of
motion that can be compared to it. The going was easier now, for it was
across a big field, and Tom told his friends that at the other end was
a deep, steep and rocky ravine in which he had decided to give the tank
another test.
"We'll imagine that ravine is a trench," he said, "and that we've got
to get on the other side of it. Of course, we won't be under fire, as
the tanks will be at the front, but aside from that the test will be
just as severe."
A little later Tank A brought her occupants to the edge of the "trench."
"Now, little girl," cried Tom exultingly, patting the rough steel side
of his tank, "show them what you can do!"
"Bless my plum pudding!" cried Mr. Damon, "are you really going down
there, Tom Swift?"
"I am," answered the young inventor. "It won't be dangerous. We'll
crawl down and crawl out. Hold fast!"
He steered the machine straight for the edge of the ravine, and as the
nose slipped over and the broad steel belts bit into the earth the tank
tilted downward at a sickening angle.
She appeared to be making the descent safely, when there was a sudden
change. The earth seemed to slip out from under the broad caterpillar
belts, and then the tank moved more rapidly.
"Tom, we're turning over!" shouted Ned. "We're capsizing!"