Japanese steel producer NKK will supply 13,000t of steel plates for use at the Three Gorges Project, in a contract won against bids from Japan, South Korea and Europe.
The plates are to be used to strengthen tunnels carrying water from the dam’s upper sluice gates to the turbines. According to NKK, the water pressure in the tunnels will be very high and therefore they will be completed using a special construction technique. In this technique the plates will be laid in a spiral formation. They will be welded at many spots at low temperature, and need to be resistant to weld cracks. NKK says that the choice of the company’s 60kg-grade high-tensile-strength steel plates was partly determined by the plates very high resistance to weld cracking.
The order was placed by China’s eighth Engineering Bureau of Water Resources and Electric Power.