The Three Gorges Dam and the History of Landmark Dams

The Three Gorges Dam

• Situated on the Yangtze River in China
• Largest concrete structure on the planet, standing over 2 kilometers long and 60 stories tall
• Built over 17 years by 40,000 workers
• Produces over 20,000 megawatts of power, twice as much as all the nuclear power stations in Britain combined

Pioneering Dams

• Lord Armstrong’s Thompson Vortex turbine: first to generate electricity using a dam, producing 4000 watts of electricity
• French hydroelectric dam on the Dordogne River: first to use a temporary coffer dam, diversion channel, and second coffer dam to build in a fast-flowing river
• Hoover Dam: first to use innovative cooling techniques to manage heat generated by concrete, completing the dam in 21 months ahead of schedule and under budget

Innovative Solutions

• Chinese engineers’ cooling techniques to prevent cracks, including cooling aggregates, adding ice, and using a fog spray system
• American engineers’ measures to prevent dam failures, including forming the bottom of the dam into a concrete ramp to dissipate overflowing water
• Three Gorges Dam’s system of 46 spillway gates and concrete chutes to release excess water
• Krasnoyarsk Dam’s steel trough to allow ships to pass through while generating power
• Three Gorges Dam’s largest shiplock on Earth and ship lift system for passenger boats

Challenges and Solutions

• Three Gorges Dam’s problem of sediment buildup behind the dam, solved by installing massive sluice gates to flush out sediment

Term	Definition	Example Usage
Cofferdam	A temporary structure built around a construction site to allow for the excavation of a trench or pit	The French hydroelectric dam on the Dordogne River used a temporary coffer dam to build in a fast-flowing river.
Thompson Vortex Turbine	A type of turbine used to generate electricity in the early days of hydroelectric power	Lord Armstrong’s Thompson Vortex turbine was the first to generate electricity using a dam, producing 4000 watts of electricity.
Diversion Channel	A channel built to divert water away from a construction site, allowing for the building of a dam or other structure	The French hydroelectric dam on the Dordogne River used a diversion channel to build in a fast-flowing river.
Second Cofferdam	A second, larger cofferdam built around the first cofferdam to allow for the construction of a dam or other structure	The French hydroelectric dam on the Dordogne River used a second coffer dam to build in a fast-flowing river.
Cooling Techniques	Chinese engineers used cooling techniques, including cooling aggregates, adding ice, and using a fog spray system, to prevent cracks in the Three Gorges Dam.
Shiplock	A passage through a dam that allows ships to pass through while generating power	The Krasnoyarsk Dam has a steel trough to allow ships to pass through while generating power.
Ship Lift System	A system used to lift passenger boats through a dam	The Three Gorges Dam has a largest ship lift system on Earth and ship lift system for passenger boats.
Sluice Gates	Large gates used to control the flow of water through a dam	The Three Gorges Dam installed massive sluice gates to flush out sediment that had built up behind the dam.
Thermal Management	American engineers used measures to prevent dam failures, including forming the bottom of the dam into a concrete ramp to dissipate overflowing water.
Sediment Buildup	The accumulation of sediment behind a dam	The Three Gorges Dam had a problem of sediment buildup behind the dam, which was solved by installing massive sluice gates to flush out sediment.

https://www.youtube.com/watch?v=I7fzJsMS8Bo

Vocabulary Quiz

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1. What does the word “pioneering” mean in the context of the text?
   • A) Relating to a location near the river
   • B) Involving new or innovative ideas or methods
   • C) Concerned with the construction of dams
   • D) Referring to a specific type of turbine
2. What is the meaning of the word “dissipate” in the context of the text?
   • A) To release or spread out energy or a substance
   • B) To build or construct a structure
   • C) To prevent or reduce the flow of water
   • D) To generate or produce electricity
3. What does the word “coffer” mean in the context of the text?
   • A) A type of dam or barrier
   • B) A temporary enclosure or chamber
   • C) A system of gates or chutes
   • D) A type of turbine or engine
4. What is the meaning of the word “sluice” in the context of the text?
   • A) A type of gate or valve
   • B) A system of chutes or ramps
   • C) A method of generating electricity
   • D) A type of dam or barrier
5. What does the word “vortex” mean in the context of the text?
   • A) A type of turbine or engine
   • B) A whirlpool or spiral motion of fluid
   • C) A system of gates or chutes
   • D) A type of dam or barrier

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Answer Key

1. B) Involving new or innovative ideas or methods
2. A) To release or spread out energy or a substance
3. B) A temporary enclosure or chamber
4. A) A type of gate or valve
5. B) A whirlpool or spiral motion of fluid

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Using the Passive Voice in Descriptive Texts

Explanation

The passive voice is often used in descriptive texts to focus on the action or process rather than the doer. It is commonly used to describe technical or scientific processes, as seen in the text. The passive voice can be formed using various verb tenses, such as the present simple, past simple, or past perfect. In the given text, the passive voice is used in sentences like “Built over 17 years by 40,000 workers” and “Produces over 20,000 megawatts of power”.

Quiz

Question 1
The Three Gorges Dam ____________________ over 17 years by 40,000 workers.
was built has been built is built built

Question 2
The Hoover Dam ____________________ using innovative cooling techniques to manage heat generated by concrete.
was completed has been completed completed was built

Question 3
The Three Gorges Dam ____________________ to generate electricity using a dam.
was used has been used is used uses

Question 4
The Krasnoyarsk Dam ____________________ to allow ships to pass through while generating power.
is equipped has been equipped equipped equips

Question 5
The Three Gorges Dam’s problem of sediment buildup behind the dam ____________________ by installing massive sluice gates to flush out sediment.
has been solved was solved solves is solved

Answer Key

Answer Key
1. was built
2. was built
3. was used
4. is equipped
5. has been solved