We have seen it all before – bigger ships force operators to purchase bigger cranes, and with the arrival of the Triple-E vessels it is no different especially for those terminal operators that are looking toward the future. For example already this year Yilport Holding welcomed the arrival four new super Post-Panamax gantry cranes able to handle Triple-E vessels to its Gemlik port in Turkey. Equipped with the latest technology, these new gantry cranes represent a multi-million dollar investment in the future of Yilport as the new gateway to the region. They are also the first batch of an order of eight 61 tonnes SWL, 63.5m outreach (23-wide) Paceco Portainers manufactured by Mitsui Engineering & Shipbuilding Co (MES) in Japan and are part of the Gemlik Terminal’s expansion project with a completion date set for April 2014.
Another terminal focusing on handling the Triple-E vessels in the future is APMT MVII in the port of Rotterdam, the Netherlands where 8 Kalmar (Cargotec) STS cranes, equipped fully with remote control are being installed. According to Annelies Nentjes, Marketing Manager – Cranes and Terminal Projects, Cargotec Netherlands, the trend that some of these terminals are setting for remote operator control, camera added operation, (semi)-automation components such as active sway- and skew control will be part of a standard portfolio. “Profile scanning of vessel, collision avoidance and auto-trajectory at high speed also will become more common in the future,” Nentjes added. “In addition, the application of Tandem Lift will be developed further and also the concept of a second-trolley system in combination with such systems will increase. “Trevor O’Donoghue, spokesperson for Liebherr Container Cranes, Irelands agrees and states that the continued drive for various levels of automation on new developments is becoming the ‘norm.’ “The incorporation of productivity technologies has become much more widespread on both larger and smaller cranes. This is particularly evident in busy and expanding ports,” says O’Donoghue. “In addition the demand for greener technologies continues and we have developed our product with this in mind. Our crane design with optimised weight distribution brings numerous benefits in terms of reduced materials, reduced civil works, reduced maintenance, reduced power consumption etc. The Liebherr energy efficient drive systems have been custom-designed for the Liebherr ship-to-shore crane and so require less power per cycle. Fully regenerative drives and laminated motors lead to further power savings and environmental benefits,” he added. “We are continuing work on our cranes with some significant innovation on both our drive systems and our proprietary crane management and diagnostic tools. The incorporation of technology and sensors into the cranes and the associated increase and widespread availability of computing power and storage will facilitate the monitoring of crane activity and box handling cycles like never before, with a view to further optimise all variables within this cycle.” Recent projects have seen Liebherr build some of the largest and most advanced cranes in the world including their double boom container cranes in the Port of Aliaga in Turkey. But Cargotec’s Nentjes points out that the technical challenge for the near future will be the design for Tripe-E vessel type STS cranes on brown-field terminals and the implementation of systems on civil structures with limitations. “On top of that the reliability and performance both operational as well as from a maintenance point of view will be an important selection criteria for terminals. Developments in energy savings and noise emission will also be pushed forward,” Nentjes added.
Safety & productivity
There is a general feeling that over the next ten years the design of container cranes will be further enhanced by the increase in the use of technology. “Technical developments which make crane operations safer and more productive have been integral in the development of container cranes over the last number of years and critical to meet health and safety guidelines,” explains O’Donoghue. Perhaps another point to consider is that the next generation of cranes will be high-tech and require highly trained people to operate and support them. In the case of Yilport their technicians have been sent to Japan for maintenance training and are using a crane simulator to develop the skills of the local drivers. Increasing safety and productivity is high on the list of terminal operators and Liebherr has seen an increase of the use of their LiSIM STS & RTG crane simulator. The LiSIM brings real and quantifiable benefits to a port operation. It increases port safety and productivity by providing a cost-effective and highly efficient crane operator training solution.
In the virtual port environment of a simulator, damage to cranes, vessels and other maritime equipment is completely eliminated. Likewise, using a simulator minimises the possibility of injuries to port personnel during training, and improves overall safety levels of a port by allowing trainees to spend extended time in the virtual environment, learning how to react instinctively to unexpected situations.
A word of caution
As much larger cranes come in to service some words of caution come from Micheal Jordan, CEO at Liftech Consultants about how important it is to implement regular maintenance intervals for cranes [in general].
“Educate inspectors and maintenance personnel about fatigue phenomena so they know what to look for, how to look, and which indications are important and which are not,” Jordan says. “If you have a limited budget, which most have, concentrate on avoiding catastrophes and tolerate nuisance failures. Put your money where it does the most good. Make decisions based on rational engineering analysis. Use visual inspection; but in addition, always use some magnetic particle or similar NDT methods to examine the surfaces at weld toes. Inspect full penetration welds using ultrasonic examination. Visual inspection isn’t useless; but remember by the time you can see a crack, unaided, the number of load applications before failure is often five percent of those already experienced. So a visible crack means failure will be sooner rather than later. Determine inspection intervals based on your acceptable risk. Use an acceptable risk approach and not an approach based on predicted crack growth size studies. Base the interval on crack initiation and the ability to find cracks.”
Jordan’s advice might highlight a recent case where one boom support hanger on a ship-to-shore crane was fractured. The low profile boom was extended over the ship, which was unable to depart as planned because the boom was in the way. This begged the question: why did the hanger fail? It was overload tested just weeks earlier. So how could it not be strong enough? According to Jordan the hanger fails when a fatigue crack grows in critical size. The size is critical when the work done by the deflecting cracked structure exceeds the work absorbed by the cleaving steel, resulting in brittle fracture. This failure could have been avoided if the personnel involved in the “thorough” examination understood the issues. The overload test only tests the yield strength of the structure. It can’t test the fatigue strength after there is more use. It only tests the present condition. Later, after more load cycles, which make cracks grow, the lifting capacity is less. But on this occasion there was one more event worth mentioning. When the engineer examined the failed plate, he discovered wet paint on the hanger right where the brittle failure occurred. Why was there wet paint? The original paint had been removed and the crane had been inspected by magnetic particle examination and then repainted the day before! So what went wrong? There was a load test. There was an inspection. But the players, although competent and conscientious, simply didn’t understand fatigue and brittle fracture. They thought
the overload test proved the crane was safe, a common misconception. [Jordan will go in to greater details on this ‘common misconception’ in our Container Crane & Components Supplement published with our May issue of World Port Development.]
Jordan concludes by saying that most cranes come with a recommended inspection regimen. And, based on Liftech’s research, most operators don’t follow the recommendations. They modify the plan without sufficient knowledge to make cost effective decisions. Some details that should be inspected are not and some that aren’t worth being inspected are. Considering the cost of inspections, attempts to not perform the full regimen are reasonable. Just as for earthquakes and high winds, the chance of a catastrophe fatigue failure is low and is very unlikely to occur during a particular person’s watch. But they do occur, sooner or later. Failure is unlikely. The damage, however, may be great. To conclude this article it would be silly to state the obvious – be it new cranes capable of handling the Triple-E vessels or ‘older’ cranes there is one golden rule – avoid deviating from the recommended maintenance inspection cycle.
BOX Story
e-chain solutions for cranes
For about 15 years Germany-based igus has successfully implemented roller energy chains on crane systems. Today the fourth generation of the igus roller e-chain is in use. The roller e-chain series P4 is used especially on high-speed STS cranes and is the heart of a well-functioning e-chain system. Another important component of this system is the cables. To meet the need for increased data, cable manufacturers are shifting from traditional twisted copper cables, still required for power transmission, to fibre optics, where signals are transmitted by light unaffected by any magnetic fields within the crane.
In the past, ports had numerous problems with festoon systems causing the damaging of cables through uncontrollable movement. To overcome these problems, igus has developed a complete cable programme especially for e-chain crane applications. Today, for all STS, RTG and RMG cranes igus offers their e-chain and chain-flex cable solutions, with the benefit of much shorter moving cable length compared to festoon systems, and reduced weight because of the length, but also smarter, thinner, lighter cable constructions.