Crane destined for use in Mongolian mine
A portal crane very similar to the one pictured, designed and manufactured by Condra in 2014, is being made by the same company for pre-sink work at the world’s fifth largest mine, Oyu Tolgoi in Mongolia.
Advanced mining techniques enabled by the crane’s pioneering design will fast-track the pre-sink phase at Oyu Tolgoi’s Shaft 6, the scheduled time for which will be less than a quarter of the time considered the norm – four months instead of the usual eighteen.
The Condra portal crane combines a very rapid lift speed with optimised cross travel to waiting dump trucks, a methodology radically different from the level-luffing type of crane traditionally used for presinking.
Instead, the portal’s high-speed, high-lift main hoist removes excavated spoil vertically, by kibble, through an opening in the centre of a drilling stage positioned by two separate stagewinders mounted on the same portal frame.
Lift speed is an impressive 1 metre per second – fifteen times faster than the 4 metres per minute found in standard mine workshop applications.
In addition to an innovative frame design and dramatically increased lift speed on the main hoist, the portal crane also incorporates improved drives, gearboxes and safety devices, better cabin access and enhanced operation by remote control.
Oyu Tolgoi Shaft 6 will have two of these Condra portal machines.
They will stand over the mouths of the main and auxiliary rescue shafts, and remain in place until the pre-sunk shafts have been drilled, blasted, supported, cleaned and lined with concrete.
