Platinum service

South Africa-based crane manufacturer Condra has introduced its new fully-automated overhead crane, and completed the first delivery of the system, to mining company Lonmin.

Fully-automated cranes follow a general trend away from manual control in the industrial and mining sectors, said Condra.

The company has installed increasingly sophisticated semi-automated installations in recent years, starting in 2003 with a grabbing crane installed at a Durban spice company facility for picking spices and transporting them to specific points for release over the hoppers that service blending and packing operations.

Condra recently installed the fullyautomated crane at Lonmin’s Marikana platinum mine. The crane is a 16t-capacity, 16m-span double-girder electric overhead travelling grabbing crane, featuring a customer-specified mechanical rope grab in place of a hydraulic alternative, designed to provide improved durability of mechanical operation in the abrasive operating environment of the Marikana facility.

The crane design incorporates dual hoists, one to raise and lower the load, and the other to mechanically close the grab by means of an internal sheave arrangement, which overcomes the spring-loaded open state.

Variable speed drives are fitted throughout the crane, delivering maximum speeds of 10m/min on the lift, 20m/min on cross-travel, and 40m/min on long-travel. Four long-travel motors enable automated control of all four wheels for precise crane positioning, accurate to within 5mm.

The crane is programmed by an operator from a remotely-located control room, where on-screen monitoring is accompanied by visual monitoring capability via closed-circuit television.

Condra is now offering fully-automated capability across its range of single-girder and double-girder cranes, including EOT cranes, gantry cranes, bridge cranes and cantilever cranes, available up to heavy duty Class 4.

Condra’s managing director, Marc Kleiner, said that the company was making full use of new developments in sensors, controls and software to offer a very precise positioning capability in automated applications.

“This is a capability that we will offer to our customers as an option,” said Kleiner. “We will mainly but not solely target the copper mines, especially tankhouse and copperleaching applications where we have extensive experience.”