Design Engineering – March-April 2019

(Jacob Rumans) #1
March/April | 2019


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he Port of Virginia runs a tight production schedule. As one
of the busiest ports in the United States – the sixth busiest
in the nation, according to data from the Bureau of Transpor-
tation Statistics – there is no room for unexpected downtime or
costly stoppages for unplanned equipment maintenance. So
when the port needed to add cranes to keep up with production
demands, the port’s Crane Maintenance Manager, Jeff Johnston,
faced a critical decision.
“I was asked: Would you want to go with a wheel festoon
system, a motorized festoon system or an energy chain system
from igus,’’ Johnston said. “There was no hesitation; no doubt
in my mind. We were going to go with igus.”
Danny Webb, general manager of technical support at the
Port of Virginia, initially had some doubts about the energy
chain, but it didn’t take long to erase those doubts. “Cranes are
getting bigger, they’re getting taller, they’re getting faster,” said
Webb, who has been working at the Port of Virginia for 33 years.
“It’s impressive to see the amount of technology on one piece of
equipment. The biggest surprise to me with the igus system,
being a naysayer of chains back in the day, was the reliability.”

Festoon vs. Energy Chains
When energy chains were first introduced to the material

Ship to


Maintenance-free energy chains help drive
explosive growth at Port of Virginia.

By Sean McCaskill

These cranes at the Port of
Virginia move cargo year round,
handling roughly 11 percent of
the East Coast’s total throughput,
even in harsh weather and
environmental conditions.

handling industry, they were considered something of a novelty.
Mobile gantry and ship-to-shore cranes in harbors and ports
were primarily equipped with festoon systems to provide power.
Festoon systems include wires or flat cables that carry con-
trol and power across a bridge or along a runway or monorail.
Cranes, however, are exposed to harsh weather and environ-
mental conditions. High winds, heavy rains, salt water, snow,
sleet and ice can dramatically impact a festoon system. High
usage and a strenuous environment cause excess wear and
corrosion to the festoon cables and components.
Festoon systems also require frequent inspections, repairs
and service to the wheels, trolleys and shock cords. Worn out
wheels and bearings, broken trolley saddles and bumpers,
snapped shock cords and tangled cables are all examples of the
inherent challenges. In fact, over four years, it’s not uncommon
to spend about $25,000 in repair for a festoon system, accord-
ing to a maintenance manager at a port in the United Kingdom.
In contrast, Energy chains aren’t susceptible to the harsh
conditions that impact festoon systems. The power and control
cables are run through the e-chain in their own partitions,
guided and protected at all times.
The e-chain system is then supported by a metal guide
trough structure along the entire travel distance. One end of
the chain bends into a U-shape and gets connected to the tow
arm. The other is fixed and anchored in most applications in
the center of the travel within the guide trough. Installing or
removing the power or control cable can be done easily and

Track Record
Maintenance-free components used in energy chains are one
of the key characteristics in Johnston’s recommendation to
use them in Virginia.
“We were a wheeled festoon port for years,’’ Johnston
said. “Bearings, bolts, shock cables, tow cables – all of those
components need to be maintained monthly and replaced

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