The Falkirk Wheel

The Falkirk Wheel in Scotland is the world's first and only rotating boat liftn: thang nâng thuyền quay. Opened in 2002, it is central to the ambitious £84.5m Millennium Link projectn: dự án Liên kết Thiên niên kỷ to restore navigabilityn: khả năng đi lại bằng đường thủy across Scotland by reconnecting the historic waterwaysn: đường thủy of the Forth & Clyde and Union Canalsn: kênh đào.

The major challenge of the project lay inphr: nằm ở 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 locksn: âu thuyền—enclosed sections of canal in which the water level could be raised or lowered—that stepped downv: bước xuống across a distance of 1.5 km. This had been dismantledv: tháo dỡ in 1933, thereby breaking the link. When the project was launched in 1994, the British Waterways authority were keen to create a dramatic twenty-first-century landmarkn: công trình mang tính biểu tượng thế kỷ 21 which would not only be a fitting commemorationn: sự kỷ niệm of the Millennium, but also a lasting symbol of the economic regenerationn: sự tái sinh kinh tế of the region.

Numerous ideas were submittedv: được nộp for the project, including concepts ranging from rolling eggsn: trứng lăn to tilting tanksn: bể nghiêng, from giant see-sawsn: bập bênh to overhead monorailsn: đường ray đơn trên cao. The eventual winner was a plan for the huge rotating steel boat liftn: thang nâng thuyền which was to become The Falkirk Wheel. The unique shape of the structure is claimed to have been inspired byphr: được truyền cảm hứng từ various sources, both manmadeadj: nhân tạo and natural, most notably a Celtic double-headed axen: rìu hai đầu, but also the vast turning propellern: chân vịt of a ship, the ribcagen: lồng ngực of a whale or the spinen: xương sống of a fish.

The various parts of The Falkirk Wheel were all constructed and assembledv: lắp ráp, like one giant toy building set, at Butterley Engineering's Steelworksn: nhà máy thép in Derbyshire, some 400 km from Falkirk. A team there carefully assembled the 1,200 tonnes of steel, painstakinglyadv: cẩn thận tỉ mỉ fitting the pieces together to an accuracyn: độ chính xác of just 10 mm to ensure a perfect final fit. In the summer of 2001, the structure was then dismantled and transported on 35 lorriesn: xe tải to Falkirk, before all being boltedv: bắt bu-lông back together again on the ground, and finally lifted into position in five large sections by cranen: cần cẩu. The Wheel would need to withstandv: chịu đựng immenseadj: to lớn and constantly changing stressesn: áp lực as it rotated, so to make the structure more robustadj: chắc chắn, the steel sections were bolted rather than weldedv: hàn together. Over 45,000 bolt holesn: lỗ bu-lông were matched with their bolts, and each bolt was hand-tightenedv: siết chặt bằng tay.

The Wheel consists of two sets of opposing axe-shaped armsn: cánh tay hình rìu, attached about 25 metres apart to a fixed central spinen: trục. Two diametrically opposedadj: đối diện qua đường kính water-filled 'gondolasn: cabin', each with a capacityn: sức chứa 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 displacementn: nguyên lý chiếm chỗ của Archimedes, floating objects displacev: chiếm chỗ 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 balancedadj: cân bằng and so, despite its enormous massn: khối lượng khổng lồ, it rotates through 180° in five and a half minutes while using very little power. It takes just 1.5 kilowatt-hoursn: kilowatt-giờ (5.4 MJ) of energy to rotate the Wheel—roughly the same as boiling eight small domestic kettlesn: ấm đun nước of water.

Boats needing to be lifted up enter the canal basinn: bể kênh at the level of the Forth & Clyde Canal and then enter the lower gondola of the Wheel. Two hydraulicadj: thủy lực steel gatesn: cửa are raised, so as to seal offphr: bịt kín the gondola from the water in the canal basin. The water between the gates is then pumped outv: bơm ra. A hydraulic clampn: kẹp, which prevents the arms of the Wheel moving while the gondola is dockedv: neo đậu, is removed, allowing the Wheel to turn. In the central machine roomn: phòng máy an arrayn: dãy of ten hydraulic motors then begins to rotate the central axlen: trục. The axle connects to the outer arms of the Wheel, which begin to rotate at a speed of 1/8 of a revolutionn: vòng quay per minute. As the wheel rotates, the gondolas are kept in the upright positionn: vị trí thẳng đứng by a simple gearing systemn: hệ thống bánh răng. Two eight-metre-wide cogsn: bánh răng 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 aqueductn: cầu dẫn nước situated 24 meters above the canal basin.

The remaining 11 meters of lift needed to reach the Union Canal is achieved by means of a pair of locks. The Wheel could not be constructed to elevatev: nâng cao boats over the full 35-meter difference between the two canals, owing tophr: do the presence of the historically important Antonine Walln: Tường Antonine, which was built by the Romans in the second century AD. Boats travel under this walln: bức tường via a tunneln: đường hầm, then through the locks, and finally onto the Union Canal.