Colos­sal lift for ships tested at Three Gorges

China Daily (USA) - - CHINA - By XIN­HUA in­Wuhan

Trial op­er­a­tion of a per­ma­nent ship-lift at the Three Gorges Dam in Hubei prov­ince be­gan on Sun­day, mark­ing the com­ple­tion of the Three Gorges project 22 years af­ter con­struc­tion be­gan.

The lift, de­signed by a Chi­nese and Ger­man team, is the largest and most so­phis­ti­cated in the world, ac­cord­ing to Three Gorges Co, the Sta­te­owned com­pany re­spon­si­ble for con­struc­tion.

The ver­ti­cal-hoist­ing el­e­va­tor is de­signed for small and medium-sized ships — those with a max­i­mum dis­place­ment of about 3,000 tons— to tra­verse the dam. The wa­ter level be­hind the dam may be as much as 113 me­ters higher than the river.

The lift is equipped with a ship-cham­ber, which con­tains a pool of wa­ter 120 me­ters long, 18 me­ters wide and 3.5 me­ters deep. The cham­ber, its me­chan­i­cal sys­tems and the wa­ter weigh 15,500 met­ric tons al­to­gether.

The lift has been in­stalled to com­ple­ment the ad­ja­cent five-tier ship lock, which is also the world’s largest. It has al­lowed ships to pass through since 2003.

The lock is cur­rently run­ning at full ca­pac­ity, with cargo through­put of 119.6 mil­lion tons in 2015— a mas­sive in­crease over its 34.31 mil­lion tons a decade ear­lier. The in­crease has been at­trib­uted to the boom­ing wa­ter trans­porta­tion sec­tor along the moun­tain­ous re­gions of the Three Gorges, in­clud­ing Chongqing mu­nic­i­pal­ity.

It once took a ship about three to four hours to pass the dam via the lock. The lift will cut this time to be­tween 40 min­utes and one hour.

The Three­Gorges project is a mul­ti­func­tional wa­ter con­trol sys­tem, con­sist­ing of a 2,309-me­ter long and 185me­ter high dam, a five-tier ship lock, 32 hy­dropower tur­bo­gen­er­a­tors and the new ship-lift.

The lift was in the orig­i­nal plan passed by the Na­tional Peo­ple’s Congress, China’s top leg­is­la­ture, in 1992. Be­cause of tech­ni­cal and safety con­cerns, that part of the project was put on hold in 1994.

By the end of 2009, all other con­struc­tion work at the dam had been com­pleted.

The orig­i­nal plan was to build a lift­ing mech­a­nism based on a wire-rope hoist. Ex­perts, how­ever, were con­cerned about its colos­sal scale and feared the tank used to carry ves­sels would be un­sta­ble, said Lu Youmei, for­mer gen­eral man­ager of China Three Gorges Corp.

In 2003, gear mech­a­nisms and nut-screw safety mea­sures from Ger­many were in­tro­duced to re­place the orig­i­nal plan, and work re­sumed in 2008.

The new ap­proach helps keep the lift bal­anced and is far su­pe­rior to the wire-rope hoist method, said Lu, who is also an aca­demic with the Chi­nese Academy of En­gi­neer­ing.

Over the past eight years, many ad­vances have been made. New stan­dards were set for steel smelt­ing, civil en­gi­neer­ing and man­age­ment, thanks to the con­struc­tion of the ship-lift, said Wu Xiaoyun, deputy di­rec­tor of the me­chan­i­cal and elec­tri­cal en­gi­neer­ing depart­ment of Three Gorges Co.

Boost­ing the ship­ping ca­pac­ity of the Yangtze, China’s long­est river, was one of the three ma­jor pur­poses of the Three Gorges project, along with flood con­trol and power gen­er­a­tion.

Be­fore the cre­ation of the Three Gorges reser­voir in 2003, the up­per reaches of the Yangtze were off-lim­its to big ves­sels, as the river was too nar­row and shal­low, and its many wind­ing and tur­bu­lent stretches — known as “ghost gates” — were dan­ger­ous for small boats.

CHENG MIN / XIN­HUA

A cruise ship is low­ered to the bot­tom of a ship-lift at the Three Gorges Dam in Hubei prov­ince on Sun­day. The lift is said to be the largest and most so­phis­ti­cated in the world.

Newspapers in English

Newspapers from China

© PressReader. All rights reserved.