Although the COVID-19 pandemic has created obstacles for supply chains and hindered manufacturing, companies such as Prysmian Group, which have not outsourced production, have been able to keep operations running with no interruptions.
The manufacturer of cables that are designed to cater towards crane electrification, has promoted the ‘Made In Germany’ concept, utilising its six factories in Germany, two of which focus on cranes.
Tobias Hoeft, head of sales OEM / business channel manager OEM at Prysmian Group, told CM: “The chain was still alive all the time. Prysmian was nearly 100% working out of Germany and we were still able to deliver all around the world.
“We have had challenges with closed borders but through our global network, we have colleagues in more than 50 countries who we can call on to arrange support for our customers.”
During the pandemic, container ports have stayed open as the services they provide in facilitating world trade are considered essential, particularly the transport of essential goods. While the number of new projects has slowed down, maintenance and repair work has been necessary to maintain operations.
Andrea Benedetti, product manager – specialties and OEM (cranes and mining) at Prysmian Group, stated: “We have two factories that both have almost 100 years of experience in making and producing flexible cables. This experience gives us knowledge of compounds, R&D and engineering capabilities.”
The company’s acquisitions of General Cable in 2018 and Draka in 2011 have also boosted its product portfolio and given it more flexibility from a logistics point of view to deal with customer requests. For example, although General Cable did not have involvement in the container business world, its expertise in bulk materials and mining provides Prysmian with a boost with regards to R&D, while its customer base in the US complements the Germany company geographically.
In recent years, container yard operations have been characterised by machinery such as automatic stacking cranes (ASCs) and automatic rail-mounted gantry (ARMG) cranes which work at high speed around the clock with minimal downtime. In this context, flexible cables are put under a high amount of mechanical stress when being reeled and unreeled at higher speeds than before and used continuously without any pauses and breaks. This poses a challenge to medium voltage reeling cables and explains why Prysmian does millions of cycles of bending tests on its cables at its testing facilities in Germany.
The aim is to make cables that are flexible and reliable with an expected lifetime that can meet the customers’ requirements. This process starts with how you make the conductor – the core in the centre is the “muscle” of the cable. Prysmian actually pulls its own strains of copper so it can start from scratch.
Hoeft explained: “Our R&D has the knowledge about what kind of copper classes we need or how many single wires we need to get one copper strand. Then also what kind of insulation material we should use and what the layout of the whole cable should look like.”
Benedetti added: “Afterwards, it comes to the quality of the materials which define whether the cable is high quality or low quality. You need rubber materials that are both very robust and very strong but are also resistant against chemicals that can be present on site and against environmental agents such as UV lights and saltwater.”
The manufacturer’s factories have a compounding area where Prysmian produces its own rubber compounds using methods and materials that are not dependent on external suppliers. This has been a critical factor during the pandemic as the company has been able to carry on producing its own compounds internally.
Having control over the “recipes” and quality of the compounds allows the company to have total knowledge over the cables’ characteristics. This also enables it to be innovative when it comes to designing new cables.
In recent years, customers have looked to reduce the overall cost of equipment where possible. With regards to cables, this means selecting them with a lower tolerance than before. Whereas previously, cables were slightly oversized to provide a buffer, both mechanically and thermally, customers and OEMs tend to make tighter selections these days, noted Benedetti.
With this in mind, Prysmian has redesigned the Protolon(SMK) medium voltage reeling cable, which has been on the market for 30 years. The new cable Protolon(SMK+HS), which is designed for ASCs and ARMGs can go beyond 270 m/minute in reeling speed, covering the current and future needs of the newest generation of terminal equipment. It has an integrated strength element in the middle, which is made of aramid yarns, providing a higher tensile load to the cable itself.
In addition, the core assembly has been optimised to make it more compact. Benedetti commented: “We were able to increase the inner sheet and outer sheet thicknesses, providing a sort of airbag system that protects the cable from external impacts and provides mechanical protection from external damages.
“We also changed the recipe of the outer sheet compound to provide a compound that is even more resistant to abrasion compared to before, which is necessary because of the increasing speed of the gantry.”
Furthermore, a light version of the Protolon(SMK) is currently in development, scheduled to be ready for sale by the end of 2020 at the latest. It will be smaller and cheaper than the original version, catering to customers who require a reeling speed of 120-180 m/minute.
Another issue that is becoming increasingly common at highly automated ports is the lack of personnel on site to monitor operations. Aside from periodic maintenance and inspections of equipment, locations such as Rotterdam’s Maasvlakte II where the ASCs are using Prysmian’s Protolon(IQ) cables, may have days with nobody on site.
This means that a defective roller or some debris on the ground may go unnoticed before harming a cable via strong abrasion or stress. In an environment like this, it is important that the equipment is “able to talk directly to us and provide feedback,” noted Benedetti. That is why the manufacturer has developed the Protolon(IQ) cable with an embedded sensor inside.
The sensors are able to monitor the mechanical stress and the thermal stress of the cable during operations. If a situation arises where the cable is stressed too much or if there is a temperature increase in a certain portion of the cable, this information is fed directly to Prysmian. Customers can discuss with the company on how they want the data to be integrated, potentially on cloud systems or in the crane management system (CMS).
Looking to the future, Prysmian wants to address the growing green trend in the container port market. In particular, the company is eliminating any materials inside its cables that are non-recyclable, removing lead from all its insulation compounds a couple of years ago for example. In addition, it is working with system integrators and OEMs to provide cables that can be used in shore power systems, one of the key ways vessel calls at ports can be made more environmentally friendly.