Decent cable management continues to be an important issue within modern crane technology. The requirements facing all variations of crane applications are intense and must include speeds, precision and travel distances. Various standards must be understood when regarding the international overhead crane market and manufacturers and end-users seek electrification solutions that can be adapted to the correct scenario. While the components need to be modular, they should also always be easy to install, and be low maintenance and cost-effective. The two power supply variants that engineers regard in order to meet these demands are festoons and energy chains.

Festoon systems are designed to provide direct electrification with flat or round cables. The cables in festoons are hung from trolleys that stack together at the rear of the crane rail. While this structure allows defined linear guidance, it takes up space on the crane rail and limits the amount of crane travel that can be achieved in a given dimensional window.

As the cables are generally clamped in bunches, it makes replacement or addition of cables a time-consuming effort. The festoon design also has a variety of linked components including wheels, tow cables, shock cords and bearings. Every individual part requires regular maintenance and lubrication, especially when exposed to rough operating environments.

In festoon systems, cables and hoses hang loose while guided. Unprotected, the lines can swing and become tangled and caught in the crane structure, especially during harsh weather which can lead to expensive repairs. Festoons often use flat composite cables that have multiple conductors in a single jacket. When these cables are used the entire composite cable may need to be replaced if one conductor is damaged. For instance, ship-to-shore cranes are often found to be equipped with festoons. When this application environment is exposed to high winds, heavy rain, ice and other environments, festoon users face high costs for repairs caused by wear and weather. This accounts to more downtime wasted on maintenance and inspections. The hanging cables and steel-dominated structure of festoons also requires ample space for setup.

To avoid the maintenance and costs that come with festoons, users are leaning towards an alternative electrification system—the energy chain. The high performance plastic e-chain allows for demanding operating environments amidst corrosion and wear resistant features, with a simple design and easy installation.

The energy chain is designed to be highly efficient, with cables securely guided in the system alongside interior separators, so they are unable to cross over one another and become tangled. For strain relief cables are tightly clamped and can be easily and individually released for repair or replacement. While in festoons an entire composite cable may need to be replaced if one conductor is damaged. With e-chains, only the one damaged cable would have to be swapped.

Since the e-chain does not require a loop parking station, a center mounted e-chain system requires approximately 50% less cable than a festoon system. This considerably reduces mechanical stress, system weight and acquisition costs. With no hanging loops, the required operating window is also far less than festoon systems, noteworthy for applications with restricted space.

Installation is simplified with the e-chain. A guide trough is installed on the crane girder, and the e-chain is populated with cables and then installed into the trough. The moving end is attached to the trolley and the cables are routed to their connection points. Energy chains can be pre-populated with cables by the energy chain manufacturer, making installation even more straightforward. Horizontal, vertical, rotary and three-dimensional movements are also achievable. While festoon wheels, shock cords and bearings are marked for wear and require replacement or lubrication, the chains are maintenance-free and only need basic visual inspections to ensure the system is in decent working order.

The e-chain is engineered to protect cables from debris and extreme weather conditions. Due to the clean and durable design, the e-chain is proven to withstand the most demanding environments. Wind is no match for the system, as cables are securely guided and cannot get caught at any point. The predefined bending radius also prevents the cables from being bent below the manufacturer’s recommended bend radius, which sometimes happens with free-hanging festoons. For additional protection, the chains are available with integrated rollers for very long travel distances, as well as special materials for chemical resistance. The rugged energy chain can be configured in many different ways, from use on hoist trolleys at high speeds to managing long runway travels with special requirements. This modularity can be applied to a wide variety of applications, including both outdoor gantry cranes and indoor bridge cranes.