07 September 2009 Green technologies are central to most modern gantry crane systems. David Pittman reports.
Customers are placing demands for environmental best practice on companies across the business spectrum, and the issue of emissions in the changing global climate is a continuing political hot potato.
World leaders are expected to settle on a framework agreement for combating climate change post-2012 at the United Nations Climate Change Conference in Copenhagen in December, which will follow-on from the end of the first commitment period of the Kyoto Protocol that passes at the end of 2012. In addition, new engine emissions standards around the world are coming to the fore and focusing operators’ and customers’ thoughts on the impact their equipment is having on the environment. This includes Stage III/IV in Europe and Tier 4 in the US.
As a result, supply chains are coming under increased scrutiny to make sure they are doing their part, and supply chain partners, such as port operators, are having to look more closely at the technologies they employ and the emissions their operations produce.
The global economic slump has also placed an impetus on using these technologies to reduce costs, with a heavy focus on reducing the use of fuel, which has seen its price rise over the last few years, and other exhaustible energy resources.
In response to this, the port equipment industry has developed a variety of technologies and systems, and many have now been fully road tested at the dockside. This includes zero emission models, all-electric models, regenerative breaking and engine efficiencies.
For instance, Konecranes says its range of fuel-saving RTGs can yield fuel savings of up to 30% by optimising the diesel generator to increase efficiency and reduce fuel consumption. This is done by adjusting the equipment’s RPMs according to the variable actual power requirement; meaning the engine is driven efficiently and high-speed idling is eliminated. Konecranes’ figures show the savings using fuel-saving rubber-tyred gantry cranes (RTGs), based on 5,000 operating hours a year involving 25t containers, can vary from over EUR25,000 to more than EUR30,000, depending on the number of containers handled per hour.
At the port
DP World is a leading international marine terminal operator with operations in the EMEA region, Asia Pacific, Australia and the Americas. As such, environmental best practice is never far from its thoughts. It states that it is “engaged in activities to limit the environmental impact of its business operations, particularly by employing industry-leading techniques to reduce the consumption of resources such as electricity and diesel oil, and reusing and recycling where possible”.
DP World’s director of global engineering, John Arnup, says the company has had “real success” in reducing fuel costs by focusing on its machines. “We only buy eco RTGs”, he says. “We haven’t bought a normal RTG for many years.
“This is focusing on the engine. We are seeing real success here and seeing significant savings in fuel. The engine is where so called intelligences can be found.”
Arnup says one of the key elements in the specification of environmentally friendly cranes by DP World is the ability for the cranes to be able to carry out lifts at speeds that were being achieved before but cutting out idling while working.
The removal of oil from machines is another key consideration for DP World. “It is possible that oil can become a thing of the past,” says Arnup, “for example with electric wheel turns eliminating hydraulics.
“All-electric specification can mean easier maintenance, cheaper operating and the removal of oil issues.”
Arnup says DP World is also undertaking initiatives to make its older equipment more environmentally friendly, including experimenting with additives in its fuel supplies. This, Arnup says, is aimed at altering the additive-chemical balance to provide “a cleaner burn that results in a small fuel saving as well as reducing our NOx (nitrogen oxide) and SOx (sulphur oxide) emissions. Dealing with legacy equipment is a challenge,” he says.
Rail-mounted gantry cranes (RMGs) are another area that DP World is looking at to make fuel and emissions reductions. However, this is “not such a focus” says Arnup, as the performance of RMGs is reliant on how the crane is specified.
“Compromise is what it comes down to. How you operate the crane determines the size of the transformer and if it can be equipped with a smaller installed power. It’s more about management.
“There is a lot going on in terms of the environment and safety,” says Arnup. “The eco side has changed drastically in the last two years, maybe even over the last year, and it has been extremely positive.”
The Port of Houston Authority (PHA) in the US is also looking to fuel-saving RTGs to bolster its operations, having recently placed an order for nine Konecranes fuel-saving models. PHA already has 40 Konecranes RTGs in operation across its eight cargo terminals in the Gulf of Mexico, but this order represents its first experience of fuel-saving RTGs. These nine all-electric, 50t capacity cranes will be delivered to Bayport Container Terminal in July 2010, as part of the terminal’s second phase of expansion and increasing its Konecranes RTG fleet to 27.
“The customer appreciates not only the fuel-saving features and reduced fuel costs, but also the higher fleet availability that the RTGs’ all-electric systems offer,” says Jussi Sarpio, director for RTG cranes at Konecranes.
“Another important feature is the crane’s anti-sway design which increases productivity in the terminal.”
Within this drive to reduce direct fuel costs and emissions, the use of electricity has a more prominent place.
As pointed out by Arnup, hydraulics maybe a thing of the past as electric components take their place in modern machinery. Konecranes has not used hydraulics in its RTGs since 1995, and its cRTG is electrically-fed to take advantage of low-cost economies of scale.
cRTG utilises a cable reel, a feeding cable and a transformer station to power the crane from the national grid. The crane is able to work on one stack from a single feed point, which can be located at the end or the middle of the stack. This position affects how far the crane can travel, with an operating area of 150m to 730m achievable if the feed point is located at the end of the stack, or 300m to 1,460m if it is sited in the middle. An auxiliary diesel generator unit is fitted to power the crane as it moves from stack to stack, where it is then reconnected to another feed point using a plug and receptacle.
cRTG models are also able to generate their own power by taking advantage of regenerative braking. The energy generated during braking actions is fed back to the grid and means the terminal draws on less power from the power station.
Kalmar has offered its E-One² RTG since 2005, which couples a low emission diesel engine with an all-electric trolley. It is designed as an all-electric concept with no hydraulic parts. Kalmar is also developing a new electric shuttle carrier as part of its seventh generation of straddle and shuttle carriers. The ESH W offers a power package that includes a variable speed generator (VSG), a Stage IIIA engine with specific catalytic reduction technology, and an electrically controlled viscous fan. The drive system and winch hoist are both electric, and in the hybrid version, electric brake control optimises energy recovery during braking. There is also the option of stop-and-go, which shuts down the engine when the unit is not moving.
Kalmar says it developed the ESH W as its customers are developing sustainable operations as well as working to improve terminal productivity. “With the electrical shuttle carrier, we combine the possibilities of the latest green technologies with high productivity,” says Ilkka Annala, vice president of Kalmar straddle carriers at Cargotec.
“With this technology we have reduced fuel consumption and lowered CO2 emissions.”
Germany’s Gottwald is currently testing the first battery-driven automated guided vehicle (AGV) for handling containers. Working with HHLA Container Terminals GmbH, a wholly-owned subsidiary of Hamburger Hafen und Logistik AG, it is hoping to introduce container handling equipment that produces zero exhaust emissions into ports and terminals. Gottwald has retrofitted one of HHLA’s modified diesel-electric AGVs for battery power and the vehicle is undergoing testing at HHLA’s Altenwerder container terminal.
Gottwald and HHLA said the move to battery power is driven by the need “to make a sustainable contribution to environmental protection in maritime ports near urban areas”. Captain Heinrich Goller, managing director of HHLA Container Terminals, says, “Against a backdrop of growing concern about environmental issues in society, politics, households and industry, we, as terminal operators, are expected to take a more responsible stance in regard to the environment. We need to design our facilities to meet these obligations long-term and increase our investment in zero exhaust emissions technology. For cost efficiency reasons, we also need to employ highly efficient and economical technology in view of the overall difficult economic situation and increasing fuel costs predicted long-term.”
Dr Mathias Dobner, chief operating officer and chief technical officer of Gottwald, adds: “The battery AGV is an important module in the handling equipment being developed as part of Gottwald’s green range. By implementing zero emission, low consumption and thus environmentally aware technologies, we aim to meet the requirements of our customers.”
Konecranes has a low emission concept in place that advocates less as more, and covers fleets, equipment, energy sources and emissions with a variety of technologies and solutions proffered.
Konecranes says the easiest way to cut emissions is to match fleet size to operations, which means the minimum number of most effective machines are mobilised. This, it says, reduces fuel burn and the volume of non value-added activities undertaken by lifting equipment. To ensure this practice is effectively followed, Konecranes uses a dual antenna-based differential global positioning system (DGPS) on yard cranes and RAAS technology with reachstackers and straddle carriers.
DGPS is an enhancement to standard GPS that uses a network of fixed, ground-based reference stations to broadcast the difference between the positions indicated by the satellite systems and known fixed positions. RAAS is a similar technology that accurately locates the equipment in the yard.
Konecranes says this positioning system, which can also be retrofitted to existing equipment, is able to minimise unnecessary driving and maximise efficiency and productivity in the fleet. This, Konecranes says, leads to a direct cut in emissions. “It’s not only about doing the tasks right, but doing the right tasks.”
For equipment, Konecranes highlights load positioning, weight of the machinery, design and the drive system as factors that affect energy use and emissions. As such, it has introduced active load control featuring a horizontal fine-positioning system, which allows the container to be caught by moving the spreader to within a 30cm radius of the target. It is using an intelligent trolley that does not require additional machinery, meaning it is lighter. It has designed out shafts, chains and belts, with all motors in yard cranes connected directly to the gantry or trolley traverse gearboxes. And, it is fitting drives that recognise the torque pattern of lifting operations and optimise power use.
Konecranes adds the use of purification technologies “is a top priority for us”, with catalytic converters already in use for a number of years. This, Konecranes says, positions it to respond to new international standards and manufacture low emission equipment.
Kalmar’s E-One² was followed on to the market by the E-One+, which offered improved quality and safety features. However, Kalmar says “this was not enough”, and the E-One² has now been improved to meet market demands.
“Our customers recognise safety as one of the key issues for improving their operational efficiency,” says Raimo Ukkonen, vice president of Kalmar RTGs at Cargotec. “Staff should be able to perform at maximum efficiency whilst enjoying a safe working environment. As a result of our thorough hazard analysis and intense product development, we raised our market-leading RTG to a whole new level of safety.”
Improvements to the E-One² model include safer access to the cabin, left main girder and trolley via a stairway, coupled with improved stairway lighting. The crane’s EE-House has also been redesigned, with extended safety distances that exceed requirements. The new safety features comply with EN 954-1, category 3.
Kalmar says the E-One²’s new fail-safe programmable logic control platform is integral to semi-automation and brings enhanced functional safety improvements. The noise level is lower due to its re-engineered power unit enclosure and a variable speed engine, which idles at a lower speed, Kalmar says.
Further enhancements include options for a VSG and zero emission with mains supply. Marko Rasinen, marketing and product manager of Kalmar’s RTG product line, says the zero emission option means “no noise, no emissions”, as “the most efficient way to decrease RTG energy consumption is to eliminate the diesel engine and provide the crane with an electrical supply”. This can see energy costs reduced by 20% compared to diesel-electric RTGs and fuel savings of up to 60% compared to conventional RTGs through the use of a VSG, an optional hybrid package and a viscous fan system. Rasinen says this equates to a reduction in CO2 emissions by as much as 100t, depending on working hours.
Kalmar’s VSG automatically optimises the engine’s RPM according to the power needed, thus resulting in lower fuel consumption. An energy optimised VSG engine equipped with super capasitors to provide energy storage powers the hybrid package.
Ports and their operators around the world have taken advantage of these options, including Gateway Terminals India operating at the Nhava Sheva port, India; LCMT at the Port of Laem Chabang in Thailand; Kumport port in Turkey; and container terminal Port Nou at the Port of Barcelona in Spain.
While eliminating emissions maybe the key target for port equipment manufacturers, three German firms are working on the technology to treat emissions from working machinery. Diesel engine manufacturer Deutz AG, automotive technology specialist Robert Bosch GmbH and exhaust technology specialist J Eberspächer GmbH have recently signed a memorandum of understanding to develop new exhaust gas treatment technologies for non-road vehicles to help meet the requirements of the Stage III/IV and Tier 4 emissions standards.
The planned joint venture will supply complete diesel exhaust systems to all engine and machinery manufacturers worldwide. The system would be based on standardised modules with customised tubing.
Deutz said each business will contribute its own specialty to the development of this technology, with Bosch contributing electronic control unit experience and its SCR metering system, Eberspächer adding its knowledge of exhaust gas after-treatment and Deutz providing experience of reducing diesel engine emissions.
With fuel costs only likely to rise for decades to come, green technologies will remain a key selling point for port cranes. And with the world’s next step in tackling climate change due to be announced in the coming months, it’s likely businesses will find themselves looking even harder at their operations and equipment to ensure they are ticking the right boxes.