“Oh, you mean the gap-bridgers?” asked Ned.
“That’s it,” answered Tom. “Look out, we’re going over a rough spot now.”
And they did. Ned was greatly shaken up, and fairly tossed from side to side of the steering tower. For the tank contained no springs, except such as were installed around the most delicate machinery, and it was like riding in a dump cart over a very rough road.
“However, that’s part of the game,” Tom observed.
Tank A reached her “harbor” safely—in other words, the machine shop enclosed by the high fence, inside of which she had been built.
Tom and Ned made some inquiries of Koku and Eradicate as to whether or not there had been any unusual sights or sounds about the place. They feared Simpson might have come to the shop to try to get possession of important drawings or data.
But all had been quiet, Koku reported Nor had Eradicate seen or heard anything out of the ordinary.
“Then I guess we’ll lock up and turn in,” decided Tom. “Come over tomorrow, Ned.”
“I will,” promised the young bank clerk. “I want to see more of what makes the wheels go round.” And he laughed at his own ingenuousness.
The next day Tom showed his friends as much as they cared to see about the workings of the tank. They inspected the powerful gasolene engines, saw how they worked the endless belts made of plates of jointed steel, which, running over sprocket wheels, really gave the tank its power by providing great tractive force.
Any self-propelled vehicle depends for its power, either to move itself or to push or to pull, on its tractive force—that is, the grip it can get on the ground.
In the case of a bicycle little tractive power is needed, and this is provided by the rubber tires, which grip the ground. A locomotive depends for its tractive power on its weight pressing on its driving wheels, and the more driving wheels there are and the heavier the locomotive, the more it can pull, though in that case speed is lost. This is why freight locomotives are so heavy and have so many large driving wheels. They pull the engine along, and the cars also, by their weight pressing on the rails.
The endless steel belts of a tank are, the same as the wheels of a locomotive. And the belts, being very broad, which gives them a large surface with which to press on the ground, and the tank being very heavy, great power to advance is thus obtained, though at the sacrifice of speed. However, Tom Swift had made his tank so that it would do about ten miles and more an hour, nearly double the progress obtained up to that time by the British machines.
His visitors saw the great motors, they inspected the compact but not very attractive living quarters of the crew, for provision had to be made for the men to stay in the tank if, perchance, it became stalled in No Man’s Land, surrounded by the enemy.
The tank was powerfully armored and would be armed. There were a number of machine guns to be installed, quick-firers of various types, and in addition the tank could carry a number of riflemen.
It was upon the crushing power of the tank, though, that most reliance was placed. Thus it could lead the way for an infantry advance through the enemy’s lines, making nothing of barbed wire that would take an artillery fire of several days to cut to pieces.
“And now, Ned,” said Tom, about a week after the night test of the tank, “I’m going to try what she’ll do in bridging a gap.”
“Have you got her in shape again?”
“Yes, everything is all right. I’ve taken out the weak part in the steering gear that nearly caused us to run you down, and we’re safe in that respect now. And I’ve got the grippers made. It only remains to see whether they’re strong enough to bear the weight of my little baby,” and Tom affectionately patted the steel sides of Tank A.
While his men were getting the machine ready for a test out on the road, and for a journey across a small stream not far away, Tom told his chum about conceiving the idea for the tank and carrying it out secretly with the aid of his father and certain workmen.
“That’s the reason the government exempted me from enlisting,” Tom said. “They wanted me to finish this tank. I didn’t exactly want to, but I considered it my ‘bit.’ After this I’m going into the army, Ned.”
“Glad to hear it, old man. Maybe by that time I’ll have this Liberty Bond work finished, and I’ll go with you. We’ll have great times together! Have you heard anything more of Simpson, Blakeson and Scoundrels?” And Ned laughed as he named this “firm.”
“No,” answered Tom. “I guess we scared off that slick German spy.”
Once more the tank lumbered out along the road. It was a mighty engine of war, and inside her rode Tom and Ned. Mary and her father had been invited, but the girl could not quite get her courage to the point of accepting, nor did Mr. Nestor care to go. Mr. Damon, however, as might be guessed, was there.
“Bless my monkey wrench, Tom!” cried the eccentric man, as he noted their advance over some rough ground, “are you really going to make this machine cross Tinkle Creek on a bridge of steel you carry with you?”
“I’m going to try, Mr. Damon.”
A little later, after a successful test up and down a small gully, Tank A arrived at the edge of Tinkle Creek, a small stream about twenty feet wide, not far from Tom’s home. At the point selected for the test the banks were high and steep.
“If she bridges that gap she’ll do anything,” murmured Ned, as the tank came to a stop on the edge.
CHAPTER XIII
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 tip 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!”
CHAPTER XIV
THE RUINED FACTORY
Only too true were the words Ned Newton shouted to his chum. Tank A was really capsizing. She had advanced to the edge of the gully and started down it, moving slowly on the caterpillar bands of steel. Then had come a sudden lurch, caused, as they learned afterward, by the slipping off of a great quantity of shale from an underlying shelf of rock.
This made unstable footing for the tank. One side sank lower than the other, and before Tom could neutralize this by speeding up one motor and slowing down the other the tank slowly turned over on its side.
“But she isn’t going to stop here!” cried Ned, as he found himself thrown about like a pill in a box. “We’re going all the way over!”
“Let her go over!” cried Tom, not that he could stop the tank now. “It won’t hurt her. She’s built for just this sort of thing!”
And over Tank A did go. Over and over she rolled, sidewise, tumbling and sliding down the shale sides of the great gully.
“Hold fast! Grab the rings!” cried Tom to his two companions in the tower with him. “That’s what they’re for!”
Ned and Mr. Damon understood. In fact, the latter had already done as Tom suggested. The young inventor had read that the British tanks frequently turned turtle, and he had this in mind when he made provision in his own for the safety of passengers and crew.
As soon as he felt the tank careening, Tom had pressed the signal ordering the motors stopped, and now only the force of gravity was operating. But that was sufficient to carry the big machine to the bottom of the gulch, whither she slid with a great cloud of sand, shale and dust.
“Bless my—bless my—” Mr. Damon was murmuring, but he was so flopped about, tossed from one side to the other, and it took so much of his attention and strength to hold on to the safety ring, that he could not properly give vent; to one of his favorite expressions.
But there comes an end to all things, even to the descent of a tank, and Tom’s big machine soon stopped rolling, sliding, and turning improvised somersaults, and rested in a pile of soft shale at the bottom of the gully. And the tank was resting on her back!
“We’ve turned turtle!” cried Ned, as he noted that he was standing on what, before, had been the ceiling of the observation tower. But as everything was of steel, and as there was no movable furniture, no great harm was done. In fact, one could as well walk on the ceiling of the tank as on the floor.
“But how are you going to get her right side up?” asked Mr. Damon.
“Oh, turning upside down is only one of the stunts of the game. I can right her,” was the answer.
“How?” asked Ned.
“Well, she’ll right herself if there’s ground enough for the steel
belts to get a grip on.
“But can the motors work upside down?”
“They surely can!” responded Tom. “I made ’em that way on purpose. The gasolene feeds by air pressure, and that works standing on its head, as well as any other way. It’s going to be a bit awkward for the men to operate the controls, but we won’t be this way long. Before I start to right her, though, I want to make sure nothing is broken.”
Tom signaled to the engine room, and, as the power was off and the speaking tube could be used, he called through it:
“How are you down there?”
“Right-o!” came back the answer from a little Englishman Tom had hired because he knew something about the British tanks. “’Twas a bit of nastiness for a while, but it won’t take us long to get up ag’in.”
“That’s good!” commented Tom. “I’ll come down and have a look at you.”
It was no easy matter, with the tank capsized, to get to the main engine room, but Tom Swift managed it. To his delight, aside from a small break in one of the minor machines, which would not interfere with the operation or motive force of the monster war engine, everything was in good shape. There was no leak from the gasolene tanks, which was one of the contingencies Tom feared, and, as he had said, the motors would work upside down as well as right side up, a fact he had proved more than once in his Hawk.
“Well, we’ll make a start,” he told his chief engineer. “Stand by when I give the signal, and we’ll try to crawl out of this right side up.”
“How are you going to do it?” asked Ned, as his chum crawled back into the observation tower.
“Well, I’m going to run her part way up the very steepest part of the ravine I can find—the side of a house would do as well if it could stand the strain. I’m going to stand the tank right up on her nose, so to speak, and tip her over so she’ll come right again.”
Slowly the tank started off, while Tom and his friends in the observation tower anxiously awaited the result of the novel progress. Ned and Mr. Damon clung to the safety rings. Tom put his arm through one and hung on grimly, while he used both hands on the steering apparatus and the controls.
The Tom Swift Megapack Page 264