Feature-rich hoists for wide cable cranes

The modernisation and expansion programme calls for two 23m-span overhead travelling factory cranes with capacities of 30t and 15t, and one 20t all-weather portal crane with a span of 26m.

Condra is headquartered in Johannesburg. The order, worth some R5½-million ($0.47m) was placed early in December for all three machines to be designed, manufactured and delivered by the end of February.

The cranes, which will be used to handle newly filled power cable drums, are designed to be robust and feature-rich. They have hand-held remote controls for operation from the factory floor, while control cabins allow alternative operation from elevated vantage points. There are variable frequency V-belt drives on the hoists, and load cells protect design limits and warn operators via LED lights when these limits are being approached. The portal crane features Condra’s patented storm brake.

Condra holds substantial stocks of locally manufactured spares, routinely delivering these parts to any point in South Africa within 24 hours. By contrast, European companies with local representation need several weeks to ship spare parts to South Africa.

Aberdare Cables has experience of Condra’s service through Load Mass Crane Services, the Port Elizabeth-based company behind the trouble-free operation of an initial Condra crane installed some years ago. The company will also install, commission and maintain the three new machines.

Two of the cranes will lift completed cable drums coming off the production lines into a covered storage area. Outside, the portal crane will manage the open air storage facility.

The first machine to be delivered, a 30t double-girder electric overhead travelling crane with a span of 23m, was tested and inspected in early February ahead of road delivery by Transcon Haulers, a Condra affiliate.

The remaining two machines, the 15t crane of identical span and similar configuration, and the 20t double-girder portal crane with a wider span of 26m, are at an advanced stage of manufacture.

A Condra spokesman noted that the lead time was in fact just six weeks thanks to the Christmas shutdown period enjoyed by South Africa’s engineering sector. Straightforward girder and cabin design, standardised optional features, and a lift height of eight metres on all three cranes made it possible to complete the order within the timeframe.

Incorporated technology includes the variable frequency drives on all hoists, which are adapted and set to allow lifting speeds that can be altered at will from very slow to very fast, thus minimising handling time and maximising productivity.

Condra routinely supplies variable frequencies drives of up to 100Hz across its hoist range, the spokesman explained. He also pointed out that European crane manufacturers are only this year beginning to introduce V-belt drives such as those incorporated in the Aberdare Cables hoists; Condra has for more than five years offered the reliability and lower maintenance costs afforded by this type of drive.

Condra is tipped to secure further orders resulting from the Aberdare Cables expansion programme when open ground is converted into additional factory space.