Dockside Gantry Crane - Essay Example

Dockside Gantry Crane Introduction: Requirement: To design a Dockside Gantry Crane in a Harbour as a part of the Material Handling. Producers and designers: The biggest producer of the container cranes in the world is Shanghai Zhenhua Port Machinery Company (ZPMC). In order to deliver the container cranes, they are welded to the ship's deck. The cranes are generally about 103 meters and the weight of each one of them is up to 1250 tonnes. Liebherr Container Cranes, Kalmar Industries, ZPMC, TCM Corporation, Konecranes, IMPSA, Paceco, Mitsubishi Heavy Industries, Mitsui Hyundai and Samsung are considered as the chief designers and producers of this type of cranes. The maximum cost of a crane can be as much as US$10 million and these cranes may take a duration of 2 years to be delivered. Classification of container cranes: The lifting capacity of the container cranes and the size of containers they are able to load and unload are generally considered as the basis of their classification. On this basis, the various types of container cranes are as follows: Panamax cranes: This type of crane is capable of transferring containers from such a ship that can pass through Panama Canal. Such ships can contain 12 to 13 containers in a row in their width. Post Panamax cranes: Such a crane is capable of loading and unloading containers from very wide ships. These ships are so big and capacious that they can not even pass through the Panama Canal. Normally, they can carry up to 18 containers in a row in their width. Super-Post Panamax cranes: These are known as the largest cranes in the present age. These cranes are sufficient for loading and unloading containers from very large vessels. These vessels can accommodate as much as 22 containers in a row in the dimension of their width. Sometimes this number can even exceed 22. A lifting capacity as large as 65 tonnes is required for an advanced container crane that is powerful enough to transfer two 20 ft long containers together at the same time. However, some modern cranes have been built which are designed for carrying loads as large as 120 tonnes. They are capable of lifting four 20 ft long or in other words two 40 ft long containers at one time. Not only this, in the present age, cranes have been designed for bearing loads as large as six 20 ft long containers. The weight of Post Panamax cranes is about 800 to 900 tonnes, and the weight of Super-Post Panamax cranes can range from 1600 tonnes to 2000 tonnes. “Super-PostPanamax cranes in Port of Rotterdam, these overhang by 50 m (22 rows of containers)”. (en.wikipedia.org, 2010). “All of the containers on Rita have been loaded by similar cranes to this one in Port of Copenhagen” (en.wikipedia.org, 2010). “A MAN AG container crane belonging to Patrick Corporation at Port Botany, New South Wales, Australia”. (en.wikipedia.org, 2010). (www.liebherr.com, n.d.) (www.liebherr.com, n.d.) Specifications: Cranes like are always designed in a way that would conform to the customers' demands and come up with their expectations. The properties covered by their functions as identified in (www.liebherr.com, n.d.) can be listed as follows: The enhanced speed of the Hoist and Trolley reduce the time of the cycle, i.e. up to 70/175 m/min for the Hoist and about 240 m/min for the Trolley. There is simultaneous hoisting, trolley traveling and gantry travel as a standard. The process of twin lifting of loads as large as 65 tonnes. (32.5 tonnes each). Up to 80 tonnes of tandem lift operations are possible. In other words, two containers each having a weight of 40 tonnes can be lifted together. Speed control systems are the latest and the most advanced in their type. They are Liebherr AC and DC Drive System. There is a sophisticated sort of crane management system which generates comprehensive data related to operations and the performance of the crane. It is referred to as VIRUS CAN. There is a tested and approved the mechanical type of anti-sway mechanism. Both the reliability figures and the availability figures are high and the MTBF values in a year are even less than 0.5 %. There is an effective support mechanism for the monitoring of fault and maintenance straight from the Liebherr factory through the RF link or the LAN and Modem. The design of the steel structure is firm, stable, balanced and anti-sway and the steel structure is of a very high quality. (www.kalmarind.com, n.d.) Specifications of this model: It is an STS model. It can carry up to 40 to 120 tonnes per spreader. Its outreach can range from 30 meters to more than 70 meters. The span of its rail is about 15 meters to 70 meters. It has got a 0 – 25 meters of back reach. Its drives include AC that is equipped with a regenerating unit. There is also a second trolley available, and each of the single-, twin- and tandem-lift can be exercised. (www.kalmarind.com, n.d.) “Twin 40ft Double trolley quayside container crane”. (www.zpmc.com, 2009). Specifications of this model: It has a very high lifting capacity. The double spreaders can carry up to 80 tonnes while the single spreader can carry up to 65 tonnes. The Hoisting speed of the Main trolley with a maximum load is about 90 meters per minute, which becomes as large as 180 meters per minute without load. The Trolley speed of the Main trolley is 240 meters per minute. The hoisting speed of Aft trolley with a maximum load is about 50 meters per minute which rises to a speed of 100 meters per minute without load. Whereas the Trolley speed of Aft trolley is 240 meters per minute. The Hoisting height of the Main trolley is as large as 41 meters and sometimes, it can be even more than that, while that of the Aft trolley is roughly 15 meters. It can have a maximum outreach of more than 63 meters. And its back reach is 19 meters. Its rail span is 35 meters. (www.zpmc.com, 2009). Soon after the discovery of double trolley container crane and also the double 40 feet container crane, the Super-Panamax era brought along with it the double 40 feet double trolley container crane. It has managed to gain the attention and appreciation of ports everywhere in the world on the basis of its enhanced performance and very high efficiency. ZPMC aims at providing all ports in the world with products that are high in efficiency, standard, quality, and functionality. Also, the prices of ZPMC's products are fairly low and quite reasonable. We believe that the double trolley container crane and the double 40 ft container crane will be able to gain the satisfaction and approval of port-experts all over the world once they get applied to the ports. (www.zpmc.com, 2009). Twin 40’quayside container crane: This crane is known to be made with the latest design of ZPMC. In order to fulfill the requirements of macro-scale vessels, it is designed to achieve quick loading and unloading. A contract between Dubai and ZPMC has been signed according to which, ZPMC is supposed to supply four twin 40 feet container cranes to Dubai at the start of 2005. The productivity can be increased up to 50% with the help of the new crane only if the process of loading and unloading can be enhanced. (www.zpmc.com, 2009). Chief characteristics: It is made up of two separate sets of Hoisting system, which are joined with the help of the trolley’s upper sheave and two standard telescopic spreaders which are detachable. For hoisting two 40 feet containers, their positions with respect to each other can be changed by the header blocks through the oil cylinder. (www.zpmc.com, 2009). Both of the Hoisting machinery sets are not simply united by the crane. The special differential hoisting gear reducer is one of its various unique characteristic features. The reducer can not only transmit the output power of both the motors to each spreader but also is capable of giving full power to just one spreader. Therefore, the crane is capable of making use of just one spreader to generate high productivity. (www.zpmc.com, 2009). It is able to operate twin containers each of which is 40 feet long. Its two head blocks can unite and depart in an automatic manner. Besides, the crane is able to deal with various spreader operation modes by making relative movements. It is possible to instantly relieve the headblock cylinder in order to separate the two spreaders despite the fact that the twin 40 feet container spreader is not able to hoist two 40 feet containers simultaneously above a load of 80 tonnes. After that, one spreader is tied to the top by the hoist machinery while the other is used to hoist twin 20 feet containers or even one 40 or 45 feet container (with a load as large as 65 tonnes). “Performance Parameters for Twin 40‘Quayside Container Crane (According to the Parameters for Twin 40。Cranes for the Port of Dubai)” Specifications: Its lift capacity under twin spreaders is about 80 tonnes, while that below single spreader in which two 20 feet containers are hoisted is roughly 65 tonnes. The capacity of lift under cargo beam is 100 tonnes. The speed of the Main hoist carrying an 80 tonnes load is 90 meters per minute while that with the empty spreader is 180 meters per minute. The trolley travels with a speed of 250 meters per minute and the speed of Gantry traveling is 60 meters per minute. The single boom-up time is 5 minutes. The rail gauge, outreach, and back each are 30.48 meters, 68.2 meters, and 23 meters respectively. Maximum wheel load on the seaside is 1050 KN for 8 wheels and on the landside is 850 KN for 8 wheels. 41 meters is the height of the lift on the rail and that under rail is 19.5 meters. Figures: Operation mode: An operator sitting in the cabin drives the crane. This cabin is hooked with the trolley. Rails on the top and sides of the boom as well as the girder provide the trolley with the path to run. The cargo that is mainly the containers is lifted by the trolley that the operator moves onto the ship. The crane lifts the container to the trailer by moving it over the dock with the help of straddle carriers or side lifts as soon as the container is locked with the spreader. After that, the container is shifted to the storage yard. Likewise, the process can be reversed when required. Power: Two sorts of the power source can be used to power the crane. They are as follows: 1. The generators on the crane's top driven by the diesel engine. 2. The electric power or shore power from the dock. However, the second option is used more. The main source of electricity, in this case, is the AC which ranges from 4000 volts to 12000 volts. References: Anon., 2010. “Container crane”. Available at: http://en.wikipedia.org/wiki/Container_crane. [Accessed 11 May 2010]. Anon., n.d. “Ship-to-shore container cranes”. Available at: http://www.liebherr.com/mcp/en/products_mcp.asp?menuID=109181!11605-0. [Accessed 11 May 2010]. Anon., n.d. “Products – Ship to shore cranes”. Available at: http://www.kalmarind.com/show.php?id=1020817. [Accessed 11 May 2010]. Anon., 2009. “Twin 40ft Double Trolley Quayside Container Crane”. Available at: http://www.zpmc.com/view.php?cid=25&tid=104&page=3. [Accessed 11 May 2010]. Anon., 2009. “Twin 40’Quay side container crane”. Available at: http://www.zpmc.com/view.php?tid=103&cid=25. [Accessed 11 May 2010]. Read More