Not surprisingly for such a big operation, machines and fixed plant are a major concern. Yellow River Contractors mechanical engineer Frank Jung employs some 370 personnel in a workshop and maintenance facility, which includes an oil analysis laboratory to detect upcoming problems.
Most of the major items run a 20 hour working, four hour maintenance cycle, he says. Biggest items such as four Hitachi 1800 tracked excavators with 10m3 front shovels, used in the rock quarry, are mainly worked on insitu.
The 41 Perlini 65t dumptrucks running the rock, and the14 smaller 36t EP366s carrying alluvial material and loess receive most checks at a way station on the 4km haul road to site, coming in only for overhauls.
He gives unstinting praise to the Caterpillar equipment which includes several D8 and D9 bulldozers and 992 and 988 loaders used on the borrow pits.
Most crucial item is the crushing plant, a Loro & Parisini designed and assembled unit running with MEM crushers and OMJ conveyors. 'If this goes down everything else stops,' says Jung. Output is about 1,000t hour but 'we do not need the plant 24 hours a day so there is time for maintenance'.
On the Lot Two site the dominating items are for concrete. Two American CS Johnson batching plants are central, turning out 200m3/h from four 3.4m3 mixers. They are fed to the intake work by Rotec tower conveyors or taken by bucket trucks.
Much of the formwork is carpentered for the complex intakes, which are mainly mass and reinforced concrete. Austria's Doka has been a major supplier. Five Liebherr towers cranes at the intake move the gear around, and another six work elsewhere.
Inside the tunnels, Italy's Cifa has supplied hydraulic lining formwork. Four mobile and eight stationary Putzmeister concrete pumps have been used for the lining work and concrete spraying.
Lot Two contractors had their own fleet of 33, 45t Terex dumpers; the contract involved 19M.m3 of earth- moving. Four Caterpillar D9N and two D8N were used for dozing alongside two Chinese machines. Drilling has been mainly with Tamrock wagon drills.
Schwing has supplied concrete pumps for Lot Three works. Mucking out were Komatsu excavators and Kiruna trucks, Cat loaders and excavators, and dumpers from Tatra. Formwork was made to Italy's Cifa designs. Atlas Copco equipment has been used on both Lot Two and Lot Three.