tech talk
Learn more at https://www.igus.com/energychains
Power supply in overhead cranes:
energy chains vs. festoons
shock cords
tow cables
electrical cables
festoon wheels
To avoid the maintenance and costs that come with
festoons, users are increasingly using an alternative
electrification system—the energy chain. The high-
performance plastic e-chain
®
can take on demanding
Reliable and dynamic cable management is one
of the greatest challenges in modern crane
technology. Virtually all modes of crane applications
are facing intensifying requirements regarding travel
distances, speeds and precision. In the international
overhead crane market where various standards
come into play, manufacturers and end-users
seek electrification solutions that can be adapted
to the respective scenario. While the components
must be modular, they should also be consistently
easy to install, low maintenance and cost-effective.
Engineers often turn to two power supply variants
to try and meet these demands: 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 end of the crane rail. While this structure
provides defined linear guidance, it consumes
space on the crane rail, limiting the amount of
crane travel that can be accomplished in a given
dimensional window. As the cables are essentially
clamped in bunches, it makes replacement or
addition of cables a time-consuming process. The
festoon design also incorporates a variety of linked
components, including wheels, tow cables, shock
cords and bearings. Each 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,
become tangled and get caught in the crane
structure, especially during harsh weather, which
leads to costly repairs. Often, festoons use flat
composite cables consisting of multiple conductors
in a single jacket. When these cables are used, the
entire composite cable may need to be replaced if
one conductor becomes damaged. For instance,
ship to shore cranes are often found to be equipped
with festoons. As this application environment is
exposed to high winds, heavy rain, ice and other
barriers, festoon users face high costs for repairs
caused by wear and weather. This means further
downtime wasted on maintenance and inspections.
The hanging cables and steel-dominated structure
of festoons also requires ample space for setup.
