Crane manufacturer completes maintenance dam testing

10 December 2014

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Crane manufacturer Condra has completed the testing of a series of maintenance cranes it has been commissioned to provide for De Hoop Dam.

The dam, which is the Department of Water and Sanitation's major 347m cubic metre reservoir in Limpopo province, is built on the Steelport River.

Featuring a wall that is 1015 long and 81 high, the De Hoop Dam is the 13th largest dam in South Africa.

Condra has been testing cranes that it claims are far more advanced than dam cranes the manufacturer has previously developed.

The main crane supplied by Condra is a 40-tonne system that features two auxiliary hoists of 5 tonne and 2 tonne capacities, which incorporate advanced control technology.

This control technology reads out the hook's location accurate to within two millimetres when it is lowered down a guide shaft to the target gate or fine screen, while encoders take into account rope stretch as the rope unwinds during hook descent.

"A load indicator tells the operator when the hook has successfully engaged the load, while hunting tooth limit switches help to control top, bottom and side travel so that positioning is kept as accurate as possible," the company said.

Elsewhere, the second crane for De Hoop Dam is a 12-tonne machine designed for use on valve maintenance with Condra also supplying a ball-plug hoist and an inspection cage.

According to Marc Kleiner, managing director at Condra, the most challenging aspect of this contract's design phase was meeting the operating specifications within the space constraints of the buildings that will house the cranes.

He said: "We had to design these machines not only according to operating requirements, but also in such a way that they can be moved into the buildings in sections and sub-assemblies, and assembled within.

"Pricing was also a challenge, as we were quoting against numerous local and foreign competitors with very competitive prices, but I am happy to say that we were able not only to offer the most technically adept cranes, but also the most competitively priced," Kleiner said.