Condra has manufactured and delivered a 30/10-tonne overhead crane designed to marry two mutually opposing tender specifications: high lift-height and tight overall dimension
The 30/10-ton maintenance crane being prepared for load test, showing digital readouts (left of photo) and the underslung auxiliary hoist in the background. (Image source: Condra)
The double-girder electric overhead travelling crane is for dragline house maintenance. A 30-ton crab-mounted main hoist will service hydraulic cylinders, motors and gearboxes within the house while an auxiliary 10-ton underslung hoist executes additional duties, including external loading and unloading of equipment.
Condra has delivered the machine on December 9, which was ordered in August last year.
Crane design was made complex by two customer specifications: first, the need for the main hoist to deliver a higher-than-normal lifting height measured as a percentage of the available vertical dimension; second, the requirement for overall dimensions to be sufficiently compact to enable the working crane to move in and out of the existing crane aperture in the wall of the dragline house.
These two design requirements run contrary to one another in that a greater lift height is usually achieved by designing a physically bigger hoist working from a larger crane. Condra’s machine will clear the aperture frame with just 50 millimetres to spare.
“In a nutshell, we met the customer specification by designing key crane elements to be smaller but stronger,” explained Marc Kleiner, managing director, Condra.
The newly delivered crane features digital load cell read-outs, remote control, lights, and a buffer to protect the underslung hoist against damage by other machinery working in the confined space of the dragline house. It joins a long list of lifting equipment manufactured by this Johannesburg-based company for mining applications over the past fifty-five years.
Condra has recently captured an increasing share of the sub-Saharan market for cranes and hoists. The product range encompasses capacities from 250 kg to 500 tons with a fully automated option offered on all machines.