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How Ships Climb Up to 113 Metres Over the Three Gorges Dam, Source & Pace (The WEDGE Method LLC).

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How Ships Climb Up to 113 Metres Over the Three Gorges Dam on YouTube

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  1. 0:00 “This steel tank at the Three Gorges Dam, with its equipment and the water inside, weighs about 15,500 tonnes.” [c01.00, sourced]
  2. 0:11 “A ship weighing up to 3,000 tonnes sails in.” [c01.01, sourced]
  3. 0:15 “Once the water is set back to its normal level, the tank weighs what it weighed before.” [c01.02, sourced]
  4. 0:21 “So the motors that raise it never carry the ship's weight, only friction, acceleration and small imbalances.” [c01.03, sourced]
  5. 0:30 “One danger its designers planned for runs the other way: the tank losing its water.” [c01.04, sourced]
  6. 0:36 “This is how ships climb over the dam, and what it cost to raise the river.” [c01.05, framing (no factual claim)]
  7. 0:51 “The dam stands on the Yangtze at Sandouping, in Yichang, Hubei province.” [c02.00, sourced]
  8. 0:57 “For years, ships could pass it only one way: a flight of locks with two lanes and five chambers each.” [c02.01, sourced]
  9. 1:04 “The lift beside them is the newer, faster route, for passenger ships, cargo ships and special vessels.” [c02.02, sourced]
  10. 1:12 “Depending on the water levels above and below the dam, it raises or lowers a ship anywhere from 71.2 metres up to 113.” [c02.03, sourced]
  11. 1:22 “Its tank gives a ship 120 metres by 18 of space, in water 3.5 metres deep.” [c02.04, sourced]
  12. 1:30 “The tank hangs from 256 steel ropes, each 74 millimetres thick.” [c02.05, sourced]
  13. 1:36 “They run over 128 double pulleys at the tops of four concrete towers, in a structure 169 metres high.” [c02.06, sourced]
  14. 1:46 “On the other ends of those ropes, in shafts inside the towers, hang counterweights of concrete and cast steel.” [c02.07, sourced]
  15. 1:54 “Sixteen groups of them, together as heavy as the tank and its water.” [c02.08, sourced]
  16. 1:59 “Here is the trick: a floating ship pushes aside its own weight in water.” [c02.09, sourced]
  17. 2:06 “When the ship is in, the gate closes, and the design allows five minutes to bring the water back to its set level.” [c02.10, sourced]
  18. 2:13 “So, with a floating ship and the water at its set level, the counterweights balance the tank just as before.” [c02.11, sourced]
  19. 2:20 “The drive is designed to cope with a water-level error of just 10 centimetres.” [c02.12, sourced]
  20. 2:25 “Four pinions, each turned by two 315-kilowatt motors, climb toothed racks built into the towers.” [c02.13, sourced]
  21. 2:34 “At 0.2 metres a second, the climb itself takes about ten minutes.” [c02.14, sourced]
  22. 2:39 “In 2016, its designers put the whole crossing at about 40 minutes, against more than three hours through the locks.” [c02.15, sourced]
  23. 2:47 “In September 2026, state media put the lift's average passage at about 50 minutes, down from 75 at first.” [c02.16, as reported]
  24. 2:59 “Suppose, instead, that a gate leaks badly, and the tank starts losing water.” [c03.00, sourced]
  25. 3:05 “Then the counterweights outweigh the tank, and pull upward on it.” [c03.01, sourced]
  26. 3:11 “Chinese state media say safety is why this lift had to wait.” [c03.02, as reported]
  27. 3:15 “The design approved in 1993 hoisted the tank on wire ropes.” [c03.03, sourced]
  28. 3:20 “An engineering account by the dam's operator says its safety provisions covered the loss of no more than half the tank's water.” [c03.04, as reported]
  29. 3:28 “A tank draining completely, in a short time, had not been fully considered, it says.” [c03.05, as reported]
  30. 3:34 “In 1995, the State Council's Three Gorges construction committee put the lift on hold.” [c03.06, sourced]
  31. 3:41 “The same account says Chinese tests and analysis during the pause found that a rope-hoisted tank could possibly overturn.” [c03.07, as reported]
  32. 3:50 “It also says that on a visit to a German ship lift, which it doesn't name, Chinese engineers learned it had once suffered a serious leak.” [c03.08, as reported]
  33. 4:00 “In 2003, the lift's design was switched, and the change was approved that September.” [c03.09, sourced]
  34. 4:06 “Instead of being hoisted, the tank would climb on its own pinions and racks.” [c03.10, sourced]
  35. 4:12 “Next to each drive sits a safety device: a short screw that turns inside a long nut column fixed to the tower.” [c03.11, sourced]
  36. 4:20 “As the tank moves, each screw spins in step with its pinion, without touching the thread around it.” [c03.12, sourced]
  37. 4:28 “As installed, there is a gap of 60 millimetres above the screw's thread, and another below it.” [c03.13, sourced]
  38. 4:34 “If water drains out, the load on the pinions climbs past a set limit, the motors stop, and the brakes clamp.” [c03.14, sourced]
  39. 4:42 “If the load keeps rising, a hydro-pneumatic spring in the drive deflects, the gap closes, and the screw's thread presses on the nut.” [c03.15, sourced]
  40. 4:51 “The thread locks itself, so the force goes through the nut columns into the towers, holding the tank independently of its ropes.” [c03.16, sourced]
  41. 5:01 “The biggest load the safety system was designed for doesn't come from a leak.” [c03.17, sourced]
  42. 5:07 “It comes from an empty tank, drained for maintenance, while the pit beneath it floods.” [c03.18, sourced]
  43. 5:13 “In that case, the four safety devices must resist an upward force of up to 123 meganewtons, the weight of more than 12,000 tonnes.” [c03.19, sourced]
  44. 5:24 “Construction of the lift's main structure began in 2008.” [c03.20, sourced]
  45. 5:28 “Its designers say trial operation began on September 18th, 2016, thirteen years after the locks opened.” [c03.21, as reported]
  46. 5:37 “In 2016, its German co-designers called it the largest ship lift in the world.” [c03.22, as reported]
  47. 5:46 “The locks had been carrying ships since June 2003.” [c04.00, sourced]
  48. 5:51 “Each chamber is 280 metres long and 34 wide, with at least five metres of water over its sill.” [c04.01, sourced]
  49. 5:59 “They were designed for 10,000-tonne-class convoys.” [c04.02, sourced]
  50. 6:03 “Together, the five steps are designed to lift ships up to 113 metres.” [c04.03, sourced]
  51. 6:09 “The water moves through large conduits built along both sides of the chambers, opened and shut by valves.” [c04.04, sourced]
  52. 6:18 “On one climb in 2023, People's Daily reported, the water level in chamber five rose from 65.4 metres to 86.77, level with chamber four.” [c04.05, as reported]
  53. 6:30 “At its biggest, one filling moves up to 237,000 cubic metres, in 12 minutes or less by design.” [c04.06, sourced]
  54. 6:40 “The gates that hold it back stand up to 38.5 metres tall, and a single leaf weighs up to 850 tonnes.” [c04.07, sourced]
  55. 6:53 “Now, the reservoir itself.” [c05.00, framing (no factual claim)]
  56. 6:56 “Filling began on June 1st, 2003, and within two weeks the reservoir's water level stood at 135 metres.” [c05.01, sourced]
  57. 7:05 “About a month later, just after midnight, a hillside above the Qinggan, a tributary of the Yangtze, gave way.” [c05.02, sourced]
  58. 7:14 “This was the Qianjiangping landslide, estimated at more than 20 million cubic metres.” [c05.03, sourced]
  59. 7:21 “Twenty-two boats were damaged or sunk.” [c05.04, sourced]
  60. 7:24 “Twenty-four people were killed or went missing; one study counts 11 of them as fishermen on the river.” [c05.05, as reported]
  61. 7:32 “Local officials had issued a warning two hours before, because the slope was moving.” [c05.06, sourced]
  62. 7:38 “Investigators weighed the causes differently.” [c05.07, framing (no factual claim)]
  63. 7:41 “A Kyoto University-led team, with China Geological Survey co-authors, called the reservoir's high water the trigger, on a slope already weakened by old shear planes in the rock, quarrying at its foot and heavy rain.” [c05.08, as reported]
  64. 7:57 “A Chinese team argued in 2005 that the slope's weak structure and concentrated rain were the main causes, and that the rising river and digging at its foot sped it up to some extent.” [c05.09, as reported]
  65. 8:09 “State media and AP reported the reservoir's level at 156 metres in October 2006, and at 175 for the first time in October 2010.” [c05.10, as reported]
  66. 8:22 “Raising the river also meant moving people.” [c05.11, framing (no factual claim)]
  67. 8:27 “A state-media chronology says the plan approved in 1992 projected that 1.132 million people would need resettling.” [c05.12, as reported]
  68. 8:37 “At the project's final acceptance in 2020, officials put its resettlement total at 1,310,300 people.” [c05.13, as reported]
  69. 8:47 “In May 2011, the State Council said the project still had problems that urgently needed solving: resettled people's livelihoods, the environment and geological hazards.” [c05.14, sourced]
  70. 8:59 “In 2012, Reuters reported a land ministry official as saying that, besides 20,000 people at Huangtupo, another 100,000 might be moved within three to five years because of geological risks.” [c05.15, as reported]
  71. 9:18 “The reservoir also holds back something else: sediment.” [c06.00, framing (no factual claim)]
  72. 9:23 “The Ministry of Water Resources estimates that more than 2.18 billion tonnes settled in it from June 2003 to the end of 2025.” [c06.01, as reported]
  73. 9:33 “Below the dam at Yichang, according to the ministry, the river's yearly sediment load fell from 492 million tonnes on average before 2002 to 29.7 million from 2003 to 2024.” [c06.02, as reported]
  74. 9:50 “At Datong, the river's most seaward gauging station, a 2015 study estimated that about 65 percent of the drop in sediment from the decade before the dam to the decade after was due to the dam; less rain, other dams and soil conservation explain most of the rest.” [c06.03, as reported]
  75. 10:11 “Downstream, the ministry says the river's low-water level at Yichang, at the same flow, fell by an average of four centimetres a year from 2003 to 2025.” [c06.04, as reported]
  76. 10:26 “Meanwhile, cargo through the staircase grew, with dips along the way.” [c07.00, framing (no factual claim)]
  77. 10:34 “Niu Xinqiang, an academician who took part in designing the locks, told Xinhua they were designed to pass 100 million tonnes of cargo a year, a level planners expected around 2030.” [c07.01, as reported]
  78. 10:45 “According to official figures, cargo through the locks passed that mark in 2011.” [c07.02, as reported]
  79. 10:51 “In 2025, the ministry counted 169 million tonnes through the locks, which the dam's operator called a record.” [c07.03, as reported]
  80. 11:01 “By 2013, Economic Daily reported, ships were waiting an average of 40 hours to get in.” [c07.04, as reported]
  81. 11:08 “A Hubei provincial government reply put the average wait in 2022 at 172 hours.” [c07.05, as reported]
  82. 11:16 “A 2024 paper by a researcher at the transport ministry's water transport institute put the waiting time in 2023 at 197 hours.” [c07.06, as reported]
  83. 11:27 “During planned lock maintenance in April 2026, an official shipping bulletin counted 1,717 ships waiting at once to pass the Three Gorges and Gezhouba dams.” [c07.07, as reported]
  84. 11:41 “The lift doesn't solve it: in 2025, by the ministry's count, ships through it carried about 1.4 million tonnes of cargo, against 169 million through the locks.” [c07.08, as reported]
  85. 11:54 “So a second staircase is coming. China's planning agency approved its feasibility study in 2025, and Xinhua reported the groundbreaking on June 8th, 2026.” [c07.09, as reported]
  86. 12:06 “State media say it will be a new double flight of five locks, cut into the mountain north of the old ones, with chambers 40 metres wide.” [c07.10, as reported]
  87. 12:16 “Its estimated static investment, including an upgrade of the Gezhouba locks downstream, is about 77.2 billion yuan, and the Three Gorges works are scheduled to take 112 months, including a year of preparation.” [c07.11, as reported]
  88. 12:33 “Citing feasibility-stage research, academician Niu Xinqiang told Xinhua that demand through the locks is forecast to reach 220 million tonnes a year in 2035.” [c07.12, as reported]
  89. 12:50 “Some things we could not pin down.” [c08.00, framing (no factual claim)]
  90. 12:53 “We found no regular official series of waiting times at the locks.” [c08.01, framing (no factual claim)]
  91. 12:58 “A Chinese wire report filed on July 13th, 2003, and later Chinese papers, date the Qianjiangping slide to twenty past midnight on July 13th; the Kyoto-led papers give July 14th.” [c08.02, as reported]
  92. 13:13 “And the new waterway's price and timetable are plans, until it is built.” [c08.03, framing (no factual claim)]
  93. 13:19 “For a floating ship at its set water level, the balance holds. The river, its hillsides and its traffic were never that simple.” [c08.04, framing (no factual claim)]

Sources

Corrections are listed with their time stamp under CORRECTIONS in the video's description; a correction that changes what the video claims also goes at the top of the description and in the pinned comment.