80 The Mole Machine-Low

The MOLE MACHINE FOCUS Question How do machines make tunnels?

机器是如何挖隧道的?

The Mole: A Natural Digger What are the best tools for digging a tunnel? Moles are animals that have strong paws for digging tunnels. Their paws are like shovels. They push dirt out of the way. A molehill tells you that mole tunnels are under your feet. You do not see moles above ground very often. They live underground in the tunnels they dig.

鼹鼠:天生的挖掘者挖隧道最好的工具是什么? 鼹鼠是一种爪子强壮的动物，可以用来挖地道。 它们的爪子像铲子。 它们把泥土推开。 鼹鼠丘告诉你，鼹鼠隧道就在你脚下。 你不经常在地面上看到鼹鼠。 他们住在自己挖的地道里。

Tunnel Time People make tunnels, too. Tunnels help people get from place to place. Earth has many mountains and many bodies of water. How can we move past these things to get where we need to go? One way is to dig a tunnel. We build tunnels under the water, through mountains, and even under cities! Train tunnels and sewer tunnels might run underneath your street. Wowser! Switzerland has the longest railway tunnel in the world. It is 57 kilometers (35 mi.) long.

隧道时间人们也会挖隧道。 隧道帮助人们从一个地方到另一个地方。 地球上有许多山和许多水体。 我们怎样才能越过这些事情到达我们需要去的地方呢? 一种方法是挖一条隧道。 我们在水下，在山上，甚至在城市下面建造隧道!火车隧道和下水道隧道可能在你的街道下面。 老古板!瑞士有世界上最长的铁路隧道。 它有57公里(35英里)长。

Pick Your Place Some tunnels go through hard, dry rock. Others go through sandy or muddy places. Engineers study where a tunnel should be built. They study the ground and make a plan for digging into it. Making a tunnel is not like building things in other places. If there is a problem, the digging must stop. The workers must be kept safe.

有些隧道要穿过坚硬干燥的岩石。 其他人则要经过沙地或泥泞的地方。 工程师们研究隧道应该建在哪里。 他们研究地面并制定挖掘计划。 建造隧道不像在其他地方建造东西。 如果有问题，就必须停止挖掘。 必须保证工人的安全。

Dig This! It is important to have the right machines when digging a tunnel. The first step is to dig a deep hole. Special machines carry the dirt out of the hole. A crane is used to move heavy things. A crane has pulleys to make the work easier. It has wheels and axles, too. The crane has a heavy bottom so that it will not tip over. The crane's long arm places the tunnel-boring machine into the hole. (The word bore means to make a hole.) The tunnel- boring machine is also called a mole machine.

挖!挖隧道时，有合适的机器是很重要的。 第一步是挖一个深洞。 特殊的机器把泥土从洞里运出来。 起重机是用来移动重物的。 起重机有滑轮，使工作更容易。 它也有轮子和轴。 起重机的底部很重，所以不会翻倒。 起重机的长臂将隧道掘进机放入洞中。 (bore这个词的意思是打洞。)隧道掘进机也叫鼹鼠机。

Mole Machine A mole machine is much stronger than a real mole. The mole machine can cut through rock! The front part is the cutter head. Have you ever seen a cheese grater cut cheese? The cutter head cuts through rock as if it were cheese. Behind the cutter head is the shield. It protects the workers from flying rocks. The rocks are moved out of the tunnel after they are cut. As the mole machine digs, workers put up strong rings in the tunnel. The rings keep the walls of the tunnel from falling in.

鼹鼠机器鼹鼠机器比真正的鼹鼠强壮得多。 鼹鼠机器可以切割岩石!前面的部分是刀头。 你见过奶酪刨丝机切奶酪吗? 刀头切岩石就像切奶酪一样。 刀头后面是防护罩。 它保护工人免受飞石的伤害。 岩石被切割后被移出隧道。 当鼹鼠机器挖掘时，工人们在隧道里竖起坚固的圆环。 这些环可以防止隧道壁坍塌。