This article was published in the November 2010 issue of World Port Development. To receive a pdf of the article in its original format including charts and pictures please send an email to archive@worldportdevelopment.com
One in the nest…
World Port Development brings you an update on the RTG-RMG market and highlights the new ‘nested RMGs’ concept proposed by Aecom.
The last 18 months have been difficult times for port and terminal operators and cargo handling equipment manufacturers alike. Due to the decline in container traffic many operators started to carefully plan for the purchase of new equipment which has had a knock-on effect on the equipment manufacturers. And although the market is picking up and operators are seeing an increase in container throughput, during the difficult period numerous orders were delayed or even cancelled but a few have materialised. “The Yard Crane (RTG/RMG) business in the established market has been picking up since June 2010,” said Tuomas Saastamoinen, Sales & Marketing Director, Port Cranes at Finland-based Konecranes. “However, the positive signals are still weak and the next few months will show if the development is solid. The emerging countries were largely unaffected by the downturn, and the business has been active all the time, especially in Asia.” Ireland-based Liebherr Container Cranes has recently delivered two (2) Rail Mounted Stacking Cranes (RMG) to the NCC facility Ust-Luga Container Terminal in Russia. Whilst these are the first Liebherr RMG container cranes supplied to Russia, they follow a previous order from NCC for a Ship-to-Shore (STS) crane at their terminal in Novorossiysk. According to the manufacturer each crane has a rail span of 22.30m with operational outreach on either side of 11.50m and 3.20m respectively. Lift height is 9.50m and safe working load is 40 tonnes under spreader. The company has also recently completed the delivery of six mega-max STS container cranes and ten Rubber Tyre Gantry cranes (RTG) to Gulf Stevedoring Contracting Co Ltd in Saudi Arabia. Three of the six STS and five of the ten RTGs were installed at the Jeddah North Container Terminal. The other three STS and five RTGs were supplied to Jubail Commercial Port – the first cranes to be supplied by Liebherr. The STS container cranes have a waterside outreach of 60m, span of 30m and a landside backreach of 16m, height under spreader is 41m. Safe working load is 65 tonnes under the twinlift spreader and 75 tonnes under hookbeam. A DC crane drive has been installed with their in-house Digivert speed control. The heavy duty RTG cranes are of 16 wheel configuration, span six containers plus a truck lane and stack one over five containers high. At Jeddah North Container Terminal these new container cranes work alongside the previous supplied Liebherr Super Post-Panamax cranes and RTGs. A total of eight (8) STS container cranes and twenty (20) RTGs now operate at the terminal. At the end of 2009, Austria-based Hans Kuenz commissioned another four (4) rail-mounted container gantry cranes for German client Eurogate. Eurogate operates deep sea terminals on the North Sea, in the Mediterranean region and on the Atlantic Ocean, with excellent connections to the European hinterland. The Eurogate container terminal at Hamburg is currently using six large-vessel berths, while Bremerhaven is Eurogate´s largest container terminal. Between 2002 and 2008, Kuenz installed eight RMGs for the train terminals. The latest RMGs were installed at the Hamburg and Bremerhaven harbour rail heads and are designed as a two-girder bridge. The steel construction of the gantry consists of the hinged post, the fixed post and the main girders with suspension. The hoisting rope reeving for the container hoisting gear is executed as a rigid rope-tower. This system enables swing-free travel in gantry and trolley direction, as well as with the slewing gear and the company claims that this guarantees efficient handling. In July 2010 Konecranes received its second RTG order from Turkey this year. The order is for five electrically-fed RTG cranes to be delivered to port operator Nemport in Nemrut, Aliaga Bay. These RTGs will be the first electrically-fed, eco-efficient cranes to be operated in Turkey and have a lifting capacity of 40 tonnes. “During the past few years, Konecranes has been mainly focusing on environmental features and improving the eco-efficiency of their equipment even further,” said Saastamoinen. These electrically-fed RTGs are equipped with cable reels, and reduce local emissions by up to 95%. The cranes run on electricity from the local grid and not from a diesel generator. They do not use hydraulics, stack one-over-6 containers high and are seven plus truck lane wide. Delivery is scheduled for March 2011.
New developments
Despite an understandable reticence to divulge details about new developments we can report some new technology including the rigid-rope tower on the Hans Kuenz RMG to guarantee efficient handling, the in-house Digivert speed control on the Liebherr RTG and the new generation fuel-saving systems from Konecranes. Indeed, there are several ways to increase productivity and efficiency but this means that you have to dig a little bit deeper. For example Hans Kuenz has patented a rotating travelling gear for RMGs. The company noticed that the lifetime of the wheels is limited by the wear of the wheel flanges. This wear is caused by off-track running of the wheels. The amount of wear caused by off-track running can also be influenced by tolerances and temperature changes. Therefore the patented solution allows for swiveling of the travel unit in the horizontal direction to compensate for any inclination of the travel unit. As a result all wheels are running on the track. Stabilisers on both sides of the travel unit make it possible for optimised transmission of the forces to the steel structure. This solution enables a major wear-reduction of the wheel flanges, which means a significant increase in the lifetime of the wheels. But it is not only technology that can improve productivity. Innovative ideas as seen at the Container Terminal Altenwerder in Hamburg, Germany, where two different size RMGs (one is smaller than the other) move along the same track and the smaller RMG can move under the larger one providing the operator with the possibility to operate two containers at the same time in the container stacking yard are nowadays being applied. Such a design or layout of the stacking yard by using RTG/RMG to the max is of interest to operators that are planning or re-designing the layout of their terminal. According to Louis Klusmeyer, Project Manager at US-based BergerABAM, RMG cranes are increasingly used at intermodal rail yards in the US for reasons that include higher container throughput, higher densities, zero diesel emissions, and extremely quiet operation. As a result conceptual design and planning studies have evaluated the installation of RMG cranes at numerous intermodal rail yards throughout the United States. “Several reasons also lead to the expectation of higher productivity for RMG cranes in intermodal yards. The new generation of RMG cranes is capable of cycle times of up to 40 to 50 lifts per hour. Also, RMG cranes can pick a container from an inside stack without moving all the outside containers. The combination of faster cycle time and improved pickability results in fewer, faster moves from stack to truck,” says Klusmeyer. Based on the RMG concept another design was created whereby two RMGs are working in tandem. Mark Sisson, Principal Engineer at US-based AECOM explains: “The next generation of RMG intermodal terminals may take advantage of a nested style of operation, where two groups of RMGs work together as a team. One group will service gate trucks and the storage buffer, and the other group will work trains and the storage buffer. In a nested RMG system, the train RMGs can work uninterrupted 24/7.” Sisson continues to explain that because they [the cranes] are able to work at much higher levels of productivity nested RM
G systems will work best at high volume terminals where land is limited. Nested systems are capital intensive in that a large number of expensive RMGs are required, but they allow for maximum economies of scale be generating more throughput per acre or per foot of working track. At high volumes, nested RMGs will likely result in the lowest overall cost per container handled, especially if the RMGs are automated. Nested RMGs will require sophisticated systems to prevent collisions between the two groups of RMGs, but these types of systems have been used with great success in marine terminals for some years. Both unified and nested RMG systems can work with a very high level of automation. There is no need for the drivers to be located on the crane since one remote driver is capable of managing several RMGs simultaneously. This type of automation is increasingly common on marine terminals, and rail operators are likely to follow suit for the same reasons: increased safety and productivity combined with decreased labour cost. The first nested RMG concept is in place at BNSF’s Memphis facility. “Although no one concept is optimal for all terminals, nested RMGs offer many powerful advantages in high volume intermodal terminals. They can only be expected to become more popular as land and labour costs increase and automation technology continues to mature,” Sission concluded.