Containerization of general cargo has been increasing steadily over the last three decades. The world container turnover increased from 76 million TEU in year 1988 to 544 million TEU in year 2008. As a result of substantial increase in world container turnover, container terminals have become an important component of the global transportation network. Container terminals serve the function of delivering containers to consignees and receiving containers from shippers, loading containers onto and unloading containers from vessels, trains, trucks, and then temporarily storing the containers in the storage yard. The productivity of container terminals is often measured in terms of the time necessary to load and unload containers by cranes and trucks, which are the most important and expensive equipment used in ports. Most container terminals have either initiated or in the process of initiating measures to increase their throughput and capacity by introducing new technologies, reducing equipment dwell times, and increasing storage density.
Transportation of containers between the quayside and the storage yard can be divided into a number of sub-processes according to the type of equipment involved. In most container terminals, trucks are commonly used for transporting containers between the quayside and the storage-yard. Determining the sequence of containers to be handled by trucks is one of the major issues in terminal operations. The operation efficiency of container terminals is directly impacted by the container sequencing decisions. Therefore, the major objective of this research is to develop generic models that can be used to solve truck scheduling problem that is the problem of scheduling a fleet of trucks to handle a set of non-preemptive jobs with sequence-dependent processing times and different arrival times. This objective is achieved through optimizing the makespan for loading and unloading containers in the container terminal using mixed integer programming and greedy search algorithms. The intent behind optimizing the makespan is (1) to reduce the waiting time of the trucks, (2) to cut down the operation costs, (3) to find the optimal number of trucks to be used for loading and unloading containers to and from trains and (4) to contribute towards improvement in the national economy.
In this research, development and implementation of several studies has been carried out for optimal scheduling of loading and unloading operations in container terminals. A generic model based on mixed integer programming (MIP) has been developed and its effectiveness in scheduling container loading and unloading operations has been studied. In addition to MIP model, four generic models based on different scheduling algorithms have been developed in this research. The performance of these models has been evaluated in terms of the quality of solution achieved by them. Comparison of the performance of MIP model with that of other models has revealed that although MIP model is able to produce optimal solutions but its execution time is quite high. Due to the high execution time requirements, it was concluded that MIP model has limited practical applicability to real world problems.
Major achievements of the research carried out in this thesis may be summarized as follows:
A comprehensive review of literature related to application of optimization techniques for improving container terminal operations has been carried out with a view to provide ready reference for any future work.
A comprehensive review of processes being followed, and equipment being used in container terminals has been carried out in order to put the work carried out in this research in context.
Real-world data pertaining to processing time and travel time for each container has been procured from CONCOR, and has been used to test the developed models
A generic MIP model that is transportable to any other container terminal with minimal changes has been developed for the truck scheduling problem
Analysis of several computational experiments carried out using the MIP model has revealed that the execution time requirements are quite high for solving even moderate size problems, thereby ruling out the application of MIP model to large real-world problems
Four generic models based on STF, LTF, FAT, and LBT scheduling mechanisms have been developed and their practicality in solving complex problems has been demonstrated through application to four real-world problems.
It has been demonstrated that the application of recommended models for unloading different number of train could lead to substantial savings in the cost of operations
A distinct practical advantage of the model developed in this work are that they are transportable to any other container terminal without any difficulty
Models developed in this work can be used by terminal operations managers for optimizing container terminal processes
Models recommended in this work provide a wider choice to the terminal managers as well as to customers
Finally, implementation of models developed in this work is straightforward due to the ease of interfacing
Declaration of Originality
This work reported in this thesis entitled “Some Studies on the Principles and Mechanisms for Loading and Unloading” was conducted entirely by me in the Department of Mechanical Engineering at the Faculty of Engineering and Technology, Jamia Millia Islamia, New Delhi, India. The matter embodied in this thesis has not been submitted in part or full to any other University/institution for the award of any degree or diploma.
01 July 2009
This is to certify that the thesis entitled “Some Studies on the Principles and Mechanisms for Loading and Unloading” submitted in fulfilment for the requirement of award of degree of Doctor of Philosophy is a record of bonafide work carried out by Mudar Dayoub under our supervision and guidance.
To the best of our knowledge the matter embodied in this dissertation has not been submitted in part or full to any other University/institution for the award of any degree.
I am extremely grateful to my thesis supervisor Prof. R A Khan who has provided valuable guidance for accomplishing this project work. He has been benevolent enough to take time out from his busy schedule for this project and supported me in every respect.
I am deeply indebted to my thesis co-supervisor Dr. Mohammed Sharif for his continuous support, stimulating suggestions and patience. It would not have been possible to complete this thesis without his encouragement and trust. I have learned a lot from his broad and profound knowledge during the long hours that we have spent together.
I am also grateful to my co-supervisor Dr Mohammed Suhaib for his whole hearted support , who has guided me at the start of this thesis work and introduced me to the ICD, Tughlakabad, authorities, where ideas for this Thesis work all got started.
In researching container terminals, loading and loading operations, I have met many colourful and interesting people from academia and industry that have helped tremendously. Mr. A. K. Mishra, operation Manager , Mr. Tomar, Supervisor of the Container Corporation of India Ltd., Inland Container Depot, Tughlakabad, New Delhi for their valuable suggestion and support. And Mr. Leela Dhar Kala, IIT Delhi,
In the course of the working on this thesis, I had the fortune of meeting many fine friends who assisted me in various forms. I would like to thank all of them.
Lastly, I would like to thank my family for their unceasing love and support of my endeavour, in particular, my mother my brothers and my sister. There is no way I have could have done this without their tremendous sacrifice.
The loading and unloading of materials is a human activity which has been performed since time immemorial. Due to rapid globalization of trade, many trade barriers have broken down during the last the few years. Loading and unloading of materials have become an important and specialized function in all trade activities. The importance of port handling and transportation systems has increased due to globalization of trade. Port handling and transportation systems include a network of terminals around the globe that allow manufacturers and shippers to deliver goods quickly to their customers. Increasing global trade has created the need for efficient container ports wherein the goal is to move containers as quickly as possible and at the minimum cost. Goods that are delayed at the port are inevitably tardy when delivered to the customer, and often incur late delivery charges. Two key activities in the port are (i) unloading of containers from truck and then storage in the export area, and (ii) removal of containers from storage area and then loading onto the trucks.
Container terminals (CT) primarily serve as an interface between different modes of transportation, such as domestic rail or truck transportation and deep sea maritime transport. Worldwide container trade is growing at an annual rate of 9.5%. Percentage of containerized trade in the world sea borne trade has increased from 5.8% in 1988 to 14.9% in 2006 and it is expected to go up to 35% by 2020 (Sabonge, 2006). It is anticipated that the growth in containerized trade will continue as more and more cargo is transferred from break-bulk to containers.
World containerized trade
The use of container as a universal carrier for various goods has increased rapidly during the last century. It has become a standard in worldwide transportation due to rapid increase in containerization operations over the recent years. As result of increasing world trade, new container terminals are being built and existing ones are expanded.
Figure ý1. Growth of world container turnover from 1988 to 2008
Figure ý1. Continent-wise turnover of containers
Figure ý1. shows the growth of world container turnover. Over the last two decades (1988 - 2008), the use of containers for intercontinental maritime transport has rapidly increased. Starting with 76 million twenty feet equivalent unit (TEU) in year 1988, world container turnover has reached more than 544 Million TEU in year 2008 (Drewry, 2007a). A further continuous increase in container turnover is expected in the upcoming years, especially in Asia and Europe.
Figure ý1. shows the container turnover of different continents. Containerized trade in 2008 has shown growth of the container turnover more than 5 times since the year 1989 (Etzelmueller, 2006). The world’s top 20 container ports handled 166.7 million TEU in 2004, accounting for 49.6 per cent of the world’s container port throughput, which is defined as the average number of containers being loaded and unloaded per hour per quay crane (QC).
Table ý1. Busiest ports in the World in 2004 versus 2007
(TEU)2007 (TEU)Percentage change13 Hong KongChina21,984,00023,881,000+8.6%21SingaporeSingapore21,329,00027,932,000+31%32ShanghaiChina14,557,00026,150,000+79.6%44 ShenzhenChina13,615,00021,099,000+55%55BussanSouth Korea11,430,00013,270,000+16%68KaohsiungTaiwan9,714.0009,774,670+0.6276RotterdamNetherlands8,281,00010,790,600+30.3%8-*Los AngelsUS7,321,0007,702,00099HamburgGermany7,003,0008,861,454+30.3%107DubaiUnited Arab emirates7,702,0008,923,456+15.9%*It indicates the port of Qingdao in China which had a rank of 10 in the year 2007 (Source: Drewry, 2007b)
Table ý1. presents the volume of container traffic in TEU for the most busy container terminals in the world in the year 2004 versus year 2007. The world’s top 3 container ports in terms of container throughput were Singapore, Hong Kong, and Shanghai. The port of Singapore is described in chapter 3 of this thesis. In the Asian and Pacific region, the concentration of port throughput is even more prominent, with the 10 busiest ports handling 110 million TEU or 61.3 percent of the region’s total throughput in 2004. The world’s six busiest container ports are located in the United Nations Economic and Social Commission for Asia and the Pacific (ESCAP) region, handling 27.4 per cent of world container throughput amounting to 51.1 percent of the ESCAP total. Within the South and South-West Asia sub-region, container throughput growth for Bangladesh, India and Sri Lanka has been strong. Growth in Bangladesh reached nearly 20 percent per annum during the second half of the 1990s. While Bangladesh and India suffered only a modest slowdown in 2001, the Sri Lankan transhipment port of Colombo was severely affected, recording a small absolute decline in container throughput. However, in 2003 Bangladesh recorded a comparatively strong growth rate of 19.1 per cent. The port scenario in India is briefly discussed in next section.
Port scenario in India
India is one of the world’s fastest-growing economies where the gross domestic product (GDP) showed a growth of 9.2% in 2006. India has shown an average growth of 7.6% in the 10th five year plan (2002-2007) compared to a global growth rate of 3.7%. (Lahiri, 2006). But due to global financial crisis, this growth slowed down in India from 8.9 % to 7% (Vos, 2008) Figure ý1. shows that GDP in India has grown at a fast pace from 4.5 percent in the year 2001 to 11.5 percent in the year 2005. However, the pace of growth has shown a decline in the recent years (2006-2009). One of the fields where India has made a significant progress is the transportation and ports facility. Over 95 percent of India's international trade by volume takes place through ports. However, due to the fast growing rate of the global container trade, Indian major ports are under the pressure of meeting the international demand.
The concept of ocean going containers was introduced in India for the first time in 1968 in a seminar held jointly by the Indian National Ship-owners Association (INSA), Directorate General of Shipping (DGS), the Shipping Corporation of India Ltd. (SCI) and the All India shippers Council (AISC) at Bombay.
Figure ý1. Growth rate of real GDP in India
The 7517 km long Indian coastline has 12 major ports and 187 minor/ intermediate ports out of which 139 are operable (Banger, 2007) Ports serve as the gateways to the international trade in India and are handling over 90% of foreign trade. The major ports are located at Calcutta/ Haldia, Chennai, Cochin, Ennore, Jawaharlal Nehru Port at Nhava Sheva, Kandla, Mormugao, Mumbai, New Mangalore, Paradip, Tuticorin and Vishakhapatnam, and Mundra port in Gujrat.
Performance of Indian ports
The 12 major Indian ports, which are managed by the Port Trust of India under Central Government Jurisdiction, have handled 463.84 MT (million tonnes) of cargo in 2006-2007, a growth of 9.1% against the same period of the previous year (Ravi, 2007). As on 13-3-2007, these ports handled 509 MT of cargo with an average growth rate of 10%. Figure ý1. shows the performance of major and minor ports in India in terms of traffic handled between 1990 and 2007. The major ports handled 5.541 million TEU out of which the share of the principle commodities was 12%. The 187 minor ports are under the jurisdiction of the respective State Governments, and have handled 195 MT (million tonnes) of cargo in 2006-2007. The capacity of minor ports in India has a capacity of 228 MT as on 13-3-2007 with an average growth rate of 12.6 %, (Banger, 2007). During 2005-06, major ports handled a record traffic of 423.41 million tonnes with a growth rate of 10.3 percent over the previous year, which was higher than the growth in GDP.
Figure ý1. Traffic handled at major and minor ports of India
Figure ý1. Share of principle commodities handled at major ports: 2005-2006
Of the total traffic handled at major ports, petroleum products have the largest share of about 33 percent; iron ore, 20 percent; coal, 14 percent; containers, 14 percent; fertilizer, 3 % and the rest is shared by general cargo 16 percent as shown in Figure ý1.
The performance of Indian ports does not compare favourably with that of efficient international ports. On three important parameters- capacity, productivity and efficiency, Indian ports lack in comparison to some of the major international ports. In international terms, labour and equipment, productivity levels are still very low due to the use of outdated equipment, poor training, low equipment handling levels by labour, uneconomic labour practices, idle time at berth, and time loss at shift change. Containerization is currently at 18% largely due to healthy EXIM (export ¨C import) growth of 15-20% (KPMG, 2006). However, this is still very low compared to the levels of 70% in other countries, primarily due to the lack of adequate infrastructure in terms of ports, roads, and railways.
Railways RoadsPorts and Shipping AviationOthers52%32%6%6%4%Table ý1. presents the average allocation of funds in the public transport sector during the five year plan (2002-2007). With the globalization of the Indian economy and spurt in imports and exports, the container traffic is expected to grow exponentially. It has been estimated that the growth will be of the order of 15 % (Prasad, 2005).The Government of India decided to set up Inland Container Depots (ICDs) which are also called dry ports and Container Freight Stations (CFSs). ICDs which are constructed away from the ports and provide all facilities for effecting containerized shipments; CFSs are smaller than ICDs and constructed near the ports, limited only for stuffing into and de-stuffing of cargoes from the containers (BARSYL, 2009). Indian ICDs perform many functions include stuffing, de-stuffing, locking, sealing, providing trailers chassis, railway flats, repairs, handling equipment, storage, 'facilities for reefer, customs examination and processing of customs documents, issuance of combined transport documents by carriers.
Containerization has been defined by the Containerization Institute, USA as “the utilizing, grouping or consolidating of multiple units into a larger container for more efficient movement” (Agerschou et al., 1983). Containerization is an important element of the logistics revolution that changed freight handling in the 20th century. Use of containers or other large size boxes to protect the cargo as a single unit throughout the journey is not new. In 1955 a very important man came into this business. His name was Malcolm McLean. He bought shipping company called “Pan Atlantic Steamship Corporation”. Soon he found out that the loading and unloading of trucks and ships took a lot of time and many people were needed to fulfil these tasks. McLean came up to an idea that there must be a special box/unit that can contain goods from the shipper’s house to the receiving party without unloading and loading again. This must result in less damage and must avoid steeling by thieves. This concept also results in faster loading/unloading trucks and ships and large packing materials is not needed (Meersmans, 2002). Nowadays, colourful steel containers can be seen in every major port. An exclusive overview of history of containers is given by Rath (1973). Indian railways used the containers for the first time in 1966 on the Bombay-Ahmadabad route.
Figure ý1. Growth of world maritime trade versus containers 1987 to 2004
A study of containerisation has shown that the saving in the cost of freight to shippers can be as high as 50% of the cost of freight without using the container (Khanna, 2005). As shown in Figure ý1., the strong growth in tonnage moved by container has been increasing at a rate faster than total maritime trade over the period betwen1987 and 2006 (Drewry Shipping Consultants, 2007).
Total international maritime trade volumes grew at an average of 4.1 percent per annum over the period of 1980 to 2004 with the result that by 2004 total seaborne trade was almost double to that of 1990 volume. The growth of containers grew seven times from 1980 to 2004. On the other hand, the challenge with containers lies in two areas: the mismatch between ISO (the International Organization for standardization) standards and un-standardized domestic container, and the prolific growth (highly productive) of different types of containers for cargos. Global production of container boxes in terms of annual output has increased by 76 times from 40,000 TEU in the year 1966 with a cost of 1,500 US Dollars (75000 Indian Rupees) to 3,050,000 TEU with a cost of 1,850 US Dollars (92000 Indian Rupees) per container (Raghuram, 2007).