A unique engineering achievement

一个独特的工程成就

The Falkirk Wheel in Scotland is the world's first and only rotating boat lift. Opened in 2002, it is central to the ambitious £84.5m Millennium Link project to restore navigability across Scotland by reconnecting the historic waterways of the Forth & Clyde and Union Canals.

苏格兰的法尔柯克水轮是世界上首个也是唯一一个船只升降转轮。法尔柯克水轮启用于2002年，它对于斥资8450万英镑的千禧廊道项目至关重要，该水轮通过重新连接福斯&克莱德运河和联盟运河间曾经的航路来恢复苏格兰的适航性。

这项工程的主要挑战在于福斯&克莱德运河地处低于联盟运河35米的地方。在历史上，两条运河经由11个船闸交汇在福尔柯克小镇附近，这些船闸在1．5公里的距离内逐步向下，这是运河的封闭部分，其中的水位可以升高或降低。这一设施于1933年被拆除，从而切断了运河间的联系。当项目在1994年启动时，英国航道管理局希望建立一座引入注目的21世纪里程碑式建筑，这将不仅仅是对千禧廊道的一个恰当纪念，同时还是这一地区经济复兴的持久象征。

The major challenge of the project lay in the fact that the Forth & Clyde Canal is situated 35 metres below the level of the Union Canal. Historically, the two canals had been joined near the town of Falkirk by a sequence of 11 locks - enclosed sections of canal in which the water level could be raised or lowered - that stepped down across a distance of 1.5 km. This had been dismantled in 1933, thereby breaking the link. When the project was launched in 1994, the British Waterways authority were keen to create a dramatic twenty-first­century landmark which would not only be a fitting commemoration of the Millennium, but also a lasting symbol of the economic regeneration of the region.

人们对这一项目提出了很多想法，其中包括从滚动装置到倾斜槽，从巨大的跷板到高架单轨。最终胜出的是建造巨大的旋转钢制船舶升降设备的计划，也就是之后的法尔柯克水轮。据称这一装置的独特形状受到了各种材料的启发，人工的和天然的都有，尤其是著名的凯尔特双头斧、巨大的船只转动螺旋浆、以及鲸鱼的胸膛或是鱼类的脊椎。

法尔柯克水轮的不同部分都在距离法尔柯克400公里的德比郡巴特利工程炼钢厂制造和组装，它就像一组巨大的玩具建筑一样。那里的团队仔细装配了1200吨钢铁部件，竭尽全力地以细致到仅为10毫米的精确度将零件组装在一起，以确保完美的最终合并。2001年夏天，这一设备先被拆分并用35辆货车运至法尔柯克，然后所有部件在地面上再次用螺栓连接在一起，最终通过起重机将五个部分起吊到位。水轮转动时将承担巨大并且持续变化的压力，因此为了使装置更加坚固，钢铁部件通过螺栓连接而非焊接在一起。超过45000个螺栓孔被它们的螺栓所填充，每个螺栓都由人工手动旋紧。

Numerous ideas were submitted for the project, including concepts ranging from rolling eggs to tilting tanks, from giant see­saws to overhead monorails. The eventual winner was a plan for the huge rotating steel boat lift which was to become The Falkirk Wheel. The unique shape of the structure is claimed to have been inspired by various sources, both manmade and natural, most notably a Celtic double- headed axe, but also the vast turning propeller of a ship, the ribcage of a whale or the spine of a fish.

水轮由两组相反的斧形悬臂组成，连接在一条固定的中心柱上，彼此相距约25米。有两个完全相反的充满水的“贡多拉”，每个的容量为360，000公升，它们连接于悬臂的末尾处。无论是否携带船只。贡多拉的重量总是一致。这是因为，按照阿基米德的位移原理，漂浮的物体会在水中排出他们自身的重量；因此当船只进入贡多拉时，离开贡多拉的水同船只重量完全一致。这使水轮保持平衡，所以虽然质量巨大，但是它在五分半钟的时间里旋转180度仅消耗非常小的能量。只需要1．5千瓦时(5．4兆焦耳)的能量就能旋转水轮——大约相当于烧开八小壶家用水壶中的水所需的能量。

需要被吊起的船只在福斯&克莱德运河的高度进入运河港池，之后进入水轮中较低的贡多拉。两个水力钢闸门被升起，从而把贡多拉封闭于运河港池之中，然后泵出闸门间的水。防止贡多拉停靠时水轮悬臂移动的液压夹板会被移走，让水轮得以旋转。在中心机房，十个液压发动机开始旋转中心轴。中心轴连接着水轮的外臂，外臂开始以每分钟1／8转的速度旋转。随着水轮转动，贡多拉被一个简单的齿轮装置保持在垂直位置。两个宽八米的齿轮围绕着一个宽度相同的固定内部齿轮旋转，它们被两个以相反方向转向外部齿轮的较小齿轮连接——从而确保贡多拉一直保持水平。当贡多拉到达顶部时，船只径直穿过位于运河港池上方24米处的沟渠。

The various parts of The Falkirk Wheel were all constructed and assembled, like one giant toy building set, at Butterley Engineering's Steelworks in Derbyshire, some 400 km from Falkirk. A team there carefully assembled the 1,200 tonnes of steel, painstakingly fitting the pieces together to an accuracy of just 10 mm to ensure a perfect final fit. In the summer of 2001, the structure was then dismantled and transported on 35 lorries to Falkirk, before all being bolted back together again on the ground, and finally lifted into position in five large sections by crane. The Wheel would need to withstand immense and constantly changing stresses as it rotated, so to make the structure more robust, the steel sections were bolted rather than welded together. Over 45,000 bolt holes were matched with their bolts, and each bolt was hand-tightened.

到达联盟运河所需的剩下11米起吊距离通过一对水闸来实现。罗马人在公元二世纪建造了具有历史重要性的安东尼墙，由于它的存在，人们无法在相差35米的两条运河间建造水轮以便升起船只。船只通过隧道在安东尼墙下行驶，然后经过水闸，最终进入联盟运河。

The Wheel consists of two sets of opposing axe-shaped arms, attached about 25 metres apart to a fixed central spine. Two diametrically opposed water-filled 'gondolas,' each with a capacity of 360,000 litres, are fitted between the ends of the arms. These gondolas always weigh the same, whether or not they are carrying boats. This is because, according to Archimedes' principle of displacement, floating objects displace their own weight in water. So when a boat enters a gondola, the amount of water leaving the gondola weighs exactly the same as the boat. This keeps the Wheel balanced and so, despite its enormous mass, it rotates through 180° in five and a half minutes while using very little power. It takes just 1.5 kilowatt-hours (5.4 MJ) of energy to rotate the Wheel - roughly the same as boiling eight small domestic kettles of water.

Boats needing to be lifted up enter the canal basin at the level of the Forth & Clyde Canal and then enter the lower gondola of the Wheel. Two hydraulic steel gates are raised, so as to seal the gondola off from the water in the canal basin. The water between the gates is then pumped out. A hydraulic clamp, which prevents the arms of the Wheel moving while the gondola is docked, is removed, allowing the Wheel to turn. In the central machine room an array of ten hydraulic motors then begins to rotate the central axle. The axle connects to the outer arms of the Wheel, which begin to rotate at a speed of 1/8 of a revolution per minute. As the wheel rotates, the gondolas are kept in the upright position by a simple gearing system. Two eight-metre-wide cogs orbit a fixed inner cog of the same width, connected by two smaller cogs travelling in the opposite direction to the outer cogs - so ensuring that the gondolas always remain level. When the gondola reaches the top, the boat passes straight onto the aqueduct situated 24 metres above the canal basin.

The remaining 11 metres of lift needed to reach the Union Canal is achieved by means of a pair of locks. The Wheel could not be constructed to elevate boats over the full 35-metre difference between the two canals, owing to the presence of the historically important Antonine Wall, which was built by the Romans in the second century AD. Boats travel under this wall via a tunnel, then through the locks, and finally on to the Union Canal.