Crane solutions provider Condra manufactured a second overhead crane for sugar producer Tongaat Hulett’s Maidstone sugar mill, in KwaZulu-Natal, to enhance operational capacity and help increase productivity, says Condra MD Marc Kleiner.

Delivery of the new crane is scheduled for this month, with authorised agent Natal Cranes & Hoists responsible for the installation and commissioning.

The order entails a 23-m-span double-girder electric travelling crane, equipped with a 25-t main hoist and an 8-t auxiliary hoist. The crane will be used in conjunction with the existing mill house crane and a 10-t Condra crane, which was commissioned in the bagasse store in March last year.

In the bagasse store, the 10-t crane is used to move and position conveyors that feed bagasse into Maidstone’s secondary processing system. Bagasse, left over as waste after harvesting juice from the sugar cane, is processed for use as a biofuel and in the manufacture of paper, pulp and building materials.

The new crane will assist with the operation and maintenance of the mill house.

Condra met Tongaat Hulett’s technical requirements for the new crane using modular products that facilitate the manufacture of a customised lifting solution, rather than adapting a standard, often imported, machine to fit the application.

This approach allows for a bespoke solution that meets the client’s specifications, while eliminating equipment modifications that might not entirely fit requirements or which are not entirely suited to the application, potentially leading to operational issues.

Condra’s modular design aligns closely with the theoretical ideal whereby every component of the crane – the hoist, crab, end-carriages, drives and controls – is assembled from an array of parts, with only the crane girders being manufactured from scratch.

For Tongaat Hulett’s new mill house crane, Condra has tailored its design to match the specification, with particular attention to the combinations of rope, drum and pulley to achieve the necessary hoist reeving arrangements. This ensures accurate load positioning over significant lifting heights of 12 m on the main hoist and 12.2 m on the auxiliary.

“The lifting height of 12 m is considerable. The more precise the load positioning over this sort of height, the less time is wasted placing the load exactly where it is needed. The same applies to load retrieval. Ultimately, this results in easier, faster crane operation, leading to productivity gains,” says Kleiner.

A key feature of the new crane is an air-conditioned control cabin with a docking station for the remote control, replacing the traditional hard-wired control panel.
Consequently, no separate control units are required, which enables operators to use the same control system for remote operation from the floor, from an overseeing office or docked within the cabin as part of the dashboard.

Further, digital read-outs from hoist load cells will be included, while an independent pendant control will provide support and additional operational flexibility. An ultrasonic anti-collision system will prevent accidental contact with the existing mill house crane, which will remain in the bay.

“There is no possibility of collision with the other crane because the new crane will stop before such a possibility can be realised. A mill house floor is a hot and busy place – without anti-collision systems, there is a definite possibility of driving one crane into another,” adds Kleiner.

Additional features include frequency drives on the long travel, cross travels and hoists, as well as full-length walkways with fibreglass grating on both sides of the crane. The crane is equipped with IP65-rated brakes and panels, ensuring protection against dust and damp.

Stainless-steel fasteners, floodlights, safety lights, a siren, full seam welds with rounded edges, lifting lugs and a specialised paint finish are also included.

Aside from the 10-t crane already in place and the new crane now on order, Condra has previously supplied a monorail hoist and crawl to Tongaat Hulett’s mill, in Zimbabwe.