Workington, UK-based steel rail manufacturer Corus Rail has replaced existing, freely suspended festoons on its indoor and outdoor cranes – 17 outdoor portals and nine indoor magnet cranes – with energy chains from German firm Igus.
The pre-harnessed new energy chain system comprised sturdy E4/4 heavy duty (HD) plastic energy chains, aluminium guide troughs and ‘chainflex’ cables, all specially designed for dynamic applications in rough, corrosive environments.
The location of the plant on the coast means the outdoor cranes had to withstand heavy winds, saltwater spray and sand. The cranes therefore work under changing humidity conditions as well as high temperatures.
The first Igus energy chain systems were installed in the steelworks as long as nine years ago. A Demag crane for long travel distances was converted eight years ago, followed by the trolley travel on further Demag outdoor cranes four years ago. The wear-resistant energy chains are still in operation.
According to Corus Rail, stoppage times for maintenance have never been required. With the festoons, conversely, the workers report that the components required frequent maintenance (corrosion, general wear), while accessibility was also difficult.
Servicing and necessary repair work was only possible with the aid of scaffolding or lifting platforms. With the energy chain solution, however, regular visual inspections now suffice, said Corus, to ensure that the chain has not been damaged and the cables are still correctly strain-relieved.
The new cranes are equipped with the “recently improved” E4/4 HD from Igus. It said the load bearing surfaces have been increased by 120% thanks to the bolt-bore connections of the chain.
The bolt diameter has been increased from 40 to 45mm and its length doubled from four to eight millimetres. Thanks to the significantly larger wear surfaces, the material strength and service life of the energy chain have been increased even further. This, said Igus, means the E4/4 HD is ideal for heavy loads in dirty environments (steel, cement, compost plants, docks, offshore plants) for long travels at high speeds.
The thickness of the side wall has also been increased from 22 to 29.5mm. With the inside height (80mm) and the outside height (108mm) unchanged, the energy chain runs smoothly and stably even under high additional loads.
The energy chains are filled with a ‘chainflex’ cable package specially adapted for outdoor applications. This comprises CF310 motor cables, CF9 and CF10 control cables and CFLG fibre optic cables, which are already being used successfully on hundreds of RTG (rubber-tyred gantry) cranes, according to Igus. It added: “Thanks to the use of highly abrasion-proof TPE sheaths, the cables are UV-resistant, can be used at high temperatures between -35 degrees C and +100 degrees C and are extremely resistant to media from coolants and lubricants through to bio-oils.
The 90% optical covering of the shielded cables with an angle of twist specially adapted to dynamic movements in energy chains increases the high EMC safety requirement.
The new energy chain system was delivered to Corus Rail as what Igus called a “ready-chain” complete package and installed on site. Benefits included reduced costs due to minimal installation time and the loss of hardly any valuable production time.
Richie Profitt, an electrical engineer at Corus for 35 years concluded: “The ready-chain energy chain system works, is reliable and maintenance-free.”
