For heavy use: cables on 14 container cranes in use for 12 years

Profile

• What was needed: energy chains type E4 5050 RHD, chainflex cables for movable applications
• Requirements: a space-saving and robust cable solution had to be found. The energy chain and cables are confronted with a high handling frequency and a 54-metre-long travel. In addition, there were high dynamics with speeds of up to 240m/min as well as constant weather loads.
• Industry: crane
• Success for the customer: the new energy and signal supply system offers a longer service life and allows a significantly more compact design. In an interim check 12 years after installation, the first chainflex cable set was still in place, having handled around 100,000 container movements at that time.

Clearly visible and well integrated into the design: the energy chain takes over the supply of energy and data to the gantry trolley.

Problem

Hamburger Hafen und Logistik AG (HHLA), is responsible for handling several million TEU at its four container terminals in just one quarter. With Container Terminal Altenwerder, HHLA says it operates one of the most productive and modern container handling facilities in the world.
The quay of the CTA offers space for four large container ships, which are loaded and unloaded from 14 container gantry cranes. Double-trolley container gantry cranes are used here. The main trolley takes over the transport from the ship to a platform, which is located in the middle of the bridge. From there, a second trolley - the gantry trolley - transports the container fully automatically onto one of the "Automated Guided Vehicles" (AGVs).
At that time in 2002, the energy supply to the trolleys of ship-to-shore cranes (StS) was usually still carried out using festoon systems, but designers wanted to break new ground here with energy chain systems.
They saw the old system at a disadvantage, as it was about 30 per cent heavier than an energy chain system due to the approx. 50 per cent longer cable length and the higher weight per metre of the festoon cables.
For the new e-chain system, the task was to ensure a large number of energy and signal cables in total to supply the gantry trolley, with a cable load of about 14 kilograms per metre.
With a high turnover frequency and a 54-metre-long travel distance, the chain system was also exposed to high dynamics with speeds of up to 240m/min as well as constant weather loads, which also placed considerable demands on the permanently moving cables within the e-chain.

Solution

The replacement of the festoon systems, which were still common on the gantry trolleys in 2002, with energy chains followed the decision of the responsible designers, who believed that this type of energy supply system would have a longer service life. Furthermore, they included the more compact design of the energy chains.
Due to the large number of cables, two reverse energy chains of the E4 5050 RHD type are installed on each of the container gantry cranes. They weigh between 13 and 15 kilograms per metre. ​​​​The energy chains for the CTA cranes were produced in Cologne in 2002 as "readychain". This means that the chains were filled, equipped with all accessories and mounting elements and delivered to the manufacturer of the container gantry cranes ready for connection, including the trough.
The initial fitting of an StS container crane with an energy chain instead of a festoon was a novelty at the time, but the new experiences were thoroughly positive. In 2014, when igus met again with the operator, the first chainflex cable set was still installed. By this time they must have handled several 100,000 container movements. One advantage of chainflex cables is that they are specifically developed, tested and manufactured for use in energy chains and designed for moving applications.
The highly flexible cables are tested for their performance in the 1,750 square metre test laboratory in Cologne, the largest for moving cables, with over two billion test cycles per year.
In addition to the high load limit and endurance, the cables offer the advantage of a smaller bend radius and save weight compared to conventional multicore cables.
In addition, CTA and igus removed and examined a control cable on a trial basis after six years. The result: the cable was still like new after a six-digit number of cycles. The highly abrasion-resistant jacket made of a TPE compound specially developed for this purpose contributes to this, as does the selection of materials for insulation, the type of stranding of the cables and production according to extremely high quality standards.

Proven in heavy-duty applications: the "Heavy Duty" version of the E4 energy chain.

The right moving cable for every application: the product range of the highly bend-resistant chainflex is continuously being expanded.