MEET ELME AT TOC EUROPE. STAND C14.
CARGO HANDLING Braking cranes on the run In 2011 the Japanese Association for Cargo Handling Machinery Systems, in operation with the Ministry of Land, Infrastructure and Trans<strong>port</strong>, Omaezaki Port and Shizuoka Prefectural Office conducted an experiment with dynamic rail clamps. As a result, dynamic rail clamps are now recommended for all Japanese <strong>port</strong>s. Not everyone in the braking industry agrees that rail clamps that act on the top of the crane rail are a good option for a dynamic storm brake. Several manufactures believe they are a holding brake only, and cranes should be equipped with wheel brakes to stop the crane in the long travel distance. However, many cranes are fitted with rail clamps with brake pads (rather than serrated shoes) to provide dynamic braking in an E-stop situation. Blown away In January 2010 a crane in the Port of Omaezaki was blown along the rail by wind. The <strong>port</strong> and the organisations listed above began a study to try and determine, amongst other things, whether rail clamps can effectively stop a crane in motion, and a realistic coefficient of friction (CoF) to use when specifying rail clamps (known as “rail brakes” in Japan). The biggest problem with rail clamps is that the crane rail is the braking surface. It can be wet, greasy from hydraulic oil and other contaminants, warped and uneven. To test some of these factors, Omaezaki used a crane on its west wharf fitted with a rail clamp with a pressing force of 500 kN on top of the rail, generating a braking force of around 300 kN with a maximum stroke of 10mm. Two sets of brake pads were used: one measured 290 x 125mm In an effort to prevent crane runaways, dynamic rail clamps are now recommended in Japan and the other was half that size. The linings were a metal-based synthetic resin material. The dynamic CoF of the brake was calculated in a series of experiments where the crane was accelerated to a predetermined speed and the emergency stop button was then pressed. Tests were repeated over several months to assess the impact of wear of the brake pads, in dry and wet conditions and on a greasy rail. Wide variations The first results were quite random, with dynamic CoFs varying between 0.1 and 0.4. It made little difference whether the rail was wet or dry. Grease and oils, however dramatically cut the dynamic CoF to around 0.1, and once the pads were contaminated this could not be improved by cleaning. Further investigation revealed that the biggest factor affecting performance was the state of the crane rail and the clearance between the rail and brake pad. When the test was repeated on another section of crane rail where the clearance did not exceed the specifications of the clamp, the results were much more consistent, with dynamic CoF values in the range of 0.22 to 0.36 on wet and dry rails. Doubling the size of the brake pad had little effect. The study concluded that dynamic rail clamps are able to stop cranes in a reliable, predictable manner, but there is a need for rail clamps that have more stroke tolerance to accommodate uneven crane rails. Masharahu Sinohara, executive officer for engineering and planning at Osaka Port remarked that although rail clamps are not mandatory, they are now recommended and most new STS cranes in Japan have them. Long travel target In other developments, Chinese brake manufacturer Jiangxi Huawu Brake Company has made developing electromagnetic multidisc brakes and wheel brakes for gantry long travel applications a research priority. In recent years Huawu has focused on brakes for wind turbines and it achieved sales of Yuan50M in this market in 2012. It is now targeting other industrial applications where im<strong>port</strong>ed products still dominate the domestic Chinese market, working with universities and the Jiangxi Provincial Science and Technology Department to develop new products. As far as growing its ex<strong>port</strong> business is concerned, Huawu recently stated its intention to “continue to intensify efforts to develop the international market.” It will try to leverage ZPMC’s overseas spare parts network to build a sales channel into overseas markets, but is also building an “international marketing team” to promote cooperation with foreign companies. Römer into Asia Germany-based manufacturer of brakes and other components Römer Fördertechnik GmbH has signed an exclusive representation agreement with Singapore-based Portek. Portek, which previously worked with Ican, will be Römer’s sole representative in the following markets: Singapore, Indonesia, Malaysia, Vietnam, Philippines, Thailand, Laos, Myanmar, Brunei, Cambodia and Hong Kong. The agreement also covers countries where Portek is operating terminals - currently Algeria, Gabon, Malta, Rwanda and Latvia. In its brake product line Römer has developed a new thruster called the Turbo brake lifting system (TBLS) that reduces the brake actuation time from 350-450 millisecs to 150 millisecs. Römer builds its own thrusters under the RBL (Römer Brems- Lüftgeräte) brand. Depending on the load, said the company, the apply time of a regular hydraulic thruster according to DIN 15430 amounts to ca. 300-500 millisecs. By a special control of the pump motor, this apply time is reduced to about 150 millisecs, independent of the load (even in case of a power failure) with integrated uninterrupted power supply. The control system reduces the inrush current and the thermal load on the motor, which Römer says will improve service life significantly. The TBLS can be used with drum, disk and band brakes. Römer is making a concerted push into <strong>port</strong>s and has supplied crane OEMs including Hans Kuenz, Konecranes, Terex, KSR Germany (part of Kranunion) and Paceco España. It is also targeting storm brakes, where it claims that many brakes are actually undersized because they are specified with an unrealistically high CoF for the application. Römer is adamant that the only appropriate value is µ=0.25 according to DIN 15019, but says this is frequently exceeded. As regards other crane components, Römer has developed a new buffer system that enables the piston rod of the buffer to retract Italy-based RIMA Srl has kept up a busy stream of business this year, following a strong 2012. It has received multiple orders for storm brakes for container handling cranes, in particular for automated stacking cranes (ASCs) and bulk handling cranes, placed by OEMs in Germany, India, China and the Middle East. In addition, there were im<strong>port</strong>ant orders for other hydraulic components including micro-motion control systems for <strong>port</strong> cranes and offshore applications. In the early part of this year more orders have come in, from <strong>WorldCargo</strong> news Römer’s Turbo brake lifting system actuates in just 150 millisecs when two cranes are working very closely together, and extend again when the cranes move apart. This will be particularly useful on retrofit applications where space is often constrained. ❏ RIMA storms forward OEMs including Mitsubishi Heavy Industries, Mitsui Engineering & Shipbuilding, Baltkran and PHB (in Spain). Highlight include the orders from Trans Gulf Port cranes (part of IMCC) in Abu Dhabi for the rail clamps and hydraulic trim, list and skew systems for 10 STS cranes and the rail brakes for 25 ASCs it is building for DP World, Jebel Ali Terminal 3. The 40 ASCs being supplied by Kalmar to DP World London Gateway (phase 1) are also being furnished with RIMA rail brakes. ❏ RIMA rail clamp on STS container crane in the Far East STRONG. PINTSCH BUBENZER Emergency Brakes. Made in Germany. In the sectors of container handling, shipbuilding and offshore engineering, mining, the steel industry, utilization of wind, mechanical engineering and construction of special vehicles, PINTSCH BUBENZER is a world leader in braking system design and manufacturing, with safety built into every product. Visit our homepage www.pintschbubenzer.de May 2013 71
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