Priority Berthing For Congested Ports: rationale and a model

Adverse effects on a national economy of port congestion are identified. The rationale underlying a system of priority berthing for awaiting vessels is described and contrasted with the operational system of first‐come, first‐served. A system of priority berthing is capable of minimizing the generalized social cost of congestion and this is structured mathematically as a multi‐attribute, decision‐making problem. A worked example is outlined and a computer program described.     

Book reviews

Road haulage licensing and EC Transport Policy. By K. J. Button. (Aldershot: Gower Publishing Co., 1984.) [Pp.127.] £14.50.

Bicycles and Public Transportation: New Links to Suburban Transit Markets. By Michael A. Replogle. (Bicycle Federation, Washington DC, 1983.) [Pp. 171.] US$15.95.

Urban Transport in ASEAN. By V. Setty Pendakur. (Institute of Southeast Asian Studies — Research Notes and Discussions Papers Series No. 43, 1984.) [Pp. 65] $4.50 ISBN 9971–902–67–2.

The World Railway System. By Bernard de Fontgalland (Cambridge Univerisity Press, 1984.) [Pp. 209.] £16.00.     

Interagency Collaboration for Integrated Coastal Zone Management: A Bangladesh Case Study

Protection, conservation, and development of coastal resources of Bangladesh are being pursued by a number of agencies on narrowly defined subject-matter specialization like agriculture and fisheries. Coastal resources, however, have competitive uses and need to be approached holistically. A Program Development Office set up to start the preparatory work for an ICZM program commissioned an institutional review of 15 agencies most intimately connected with activities in the coastal area to assess their institutional capacity to take part in an ICZM program. The actual performance of one of the top-ranked organizations under review was further evaluated by drawing upon case materials from five completed multisector projects in which it was the lead agency. The case study revealed that institutional capacity was a necessary but not a sufficient condition for successful joint execution of multisector programs. Organizations tend to cooperate in a multisector program only when they are given full control over the management of their own components. Any arrangements short of that will not yield the desired result. An integrated approach needs to be formalized in a manner that allows each agency to maintain its independent status while at the same time allowing it to carry out its activities within a commonly agreed framework. This model contains the elements of an institutional design for carrying out an integrated coastal zone management program in Bangladesh.     

PIV study of the effect of piston position on the in-cylinder swirling flow during the scavenging process in large two-stroke marine diesel engines

A simplified model of a low speed large two-stroke marine diesel engine cylinder is developed. The effect of piston position on the in-cylinder swirling flow during the scavenging process is studied using the stereoscopic particle image velocimetry technique. The measurements are conducted at different cross-sectional planes along the cylinder length and at piston positions covering the air intake port by 0, 25, 50 and 75 %. When the intake port is fully open, the tangential velocity profile is similar to a Burgers vortex, whereas the axial velocity has a wake-like profile. Due to internal wall friction, the swirl decays downstream, and the size of the vortex core increases. For increasing port closures, the tangential velocity profile changes from a Burgers vortex to a forced vortex, and the axial velocity changes correspondingly from a wake-like profile to a jet-like profile. For piston position with 75 % intake port closure, the jet-like axial velocity profile at a cross-sectional plane close to the intake port changes back to a wake-like profile at the adjacent downstream cross-sectional plane. This is characteristic of a vortex breakdown. The non-dimensional velocity profiles show no significant variation with the variation in Reynolds number.     

Managing community acceptance of major industrial projects

Abstract

In some cases, the major risk encountered by an industry seeking to site a facility is that of community acceptance. Without community acceptance of a proposed project, construction can be delayed, taxes can be prohibitive, and operations can be prevented through the opposition and influence of local groups. This paper describes the community acceptance risk, the traditional industrial approach to countering local opposition, and a positive approach to achieving community acceptance. This positive approach entails careful site selection; affirmative management of the community acceptance problem, including explicit planning of the community acceptance effort, assignment of staff with specific responsibilities to implement plans, and a budget for mitigating the impacts of the project on the community; acquisition of sufficient land to buffer unavoidable impacts of the project; a carefully formed corporate policy on the public release of information concerning the project; and constructive participation in state and local government policy development.     

Emergence of ‘new professionalism’ among Chinese seafarers: empirical evidence and policy implications

In this paper some of the factors that were influential in establishing a Canadian shipping policy position à proposissues raised by the UNCTAD V meeting are examined. The first of these issues was the question of early ratification and entry in force of the Conventin on a Code of Conduct for Liner Conferences. The second involved the relationship between flages of convenience and fleet expansion in the developing countries (LDCs). The third concerned LDC participation in the carriage of bulk cargoes. The author concludes that Canada's stance was determined by the fact that she was a major user of shipping withouta significant fleet of her own, and shows how she attempted to balance her sympathy with Third World aspirations with the demands of her own national interests.     

Application of warm forming aluminum alloy parts for automotive body based on impact

Aluminum alloys are important technological materials for the application on lightweight design and development of vehicle body. The research works for characterizing warm forming behavior of aluminum alloys have generally reported. However, there were few researches focused on the flow behavior of warm forming aluminum alloy parts for the energy absorbing performance during crash. The tensile stress-strain response for warm forming AA5182 specimens tested under the strain rates of 0.0015 s^?1, 0.015 s^?1, 0.15 s^?1 and 1.5 s^?1 are presented in this paper. The data were fit to the Johnson-Cook constitutive model for the simulation of frontal impact. The energy absorbing performance of warm forming AA5182 parts were analyzed. The results show the higher flow stresses and lower fractured strain of warm forming aluminum alloy parts with the strain rate increasing. The flow stresses of warm forming aluminum alloy parts are insensitive to strain rate, while the fractured strain and elongation are sensitive to strain rate. The intrusion displacement of the warm forming aluminum alloy parts is appropriate for the satisfaction of vehicle body design avoiding the excessive deformation for the injury of passenger or the failure of frontal door opening. The feasibility of warm forming aluminum alloy parts is verified with the analysis of energy absorbing performance, stiffness and modal of vehicle body.     

Measurement of the disc-pad friction coefficient for mechanical brakes using direct and indirect methods

It is necessary to guarantee the proper brake force to stop a train safely in a limited distance and o adjust its speed. Currently, most trains are run by electrical power and have a combined electrical and mechanical (friction) braking system. The mechanical brake force is determined by many parameters, such as the friction coefficient of the brake disc and pad, the pressure in the brake cylinder, the brake cylinder’s cross sectional area and the brake linkage ratio. In general, the friction coefficient data of the brake disc and pad have been taken through a dynamo-test in a laboratory, but these data might not be well matched with real data under operating conditions because of the difference in data acquisition conditions. The present study examined two methodologies that can measure the friction coefficient of the brake pad and disc based on a train’s real operating conditions. The first method was the direct method, which measured the brake force and clamping force applied on the mechanical brake by using strain gauges installed on the brake to calculate the friction coefficient. The second was an indirect method that obtained the friction coefficient by using the weight of the train and the equivalent brake force. Those variables were calculated from the longitudinal dynamic characteristics, such as resistance to motion, gradient resistance and curved resistance. These two methodologies were used to obtain the disc-pad friction coefficient for the mechanical brakes of a Korean high-speed train (HSR350x).     

Dynamic analysis of spiral bevel geared rotor systems applying finite elements and enhanced lumped parameters

The dynamics of spiral bevel gears like most high-speed precision gears employed in motor vehicles and off highway equipments are substantially affected by the structural characteristics of the shafts and bearings. The lumped parameter model is one of the common tools applied to perform gear dynamic analysis. Even though the lumped parameter approach is computationally fast and conveniently efficient, it typically uses limited number of coordinates and may not fully account for the shaft-bearing structural characteristics accurately. In this analysis, the finite element formulation, that can generally represent more complete characteristics of the shaft-bearing assembly, is employed to enhance the current lumped parameter synthesis theory using the concept of effective mass and inertia elements. Computational output shows that the enhanced lumped parameter synthesis model is capable of predicting sufficiently accurate dynamic response when compared to the direct dynamic finite element calculations, and much more precise response than previous lumped parameter results, especially when the gear dynamics are associated with the pinion or gear bending modes. Even though this analysis focuses primarily on the spiral bevel geared rotor systems, the proposed methodology and analysis results can be easily extended to other types of gears.     

Control and monitoring for railway vehicle dynamics

Over the last twenty to thirty years, railway vehicle dynamics has changed from being an essentially mechanical engineering discipline to one that is increasingly starting to include sensors, electronics and computer processing. This paper surveys the application of these technologies to suspensions and running gear, focused upon the complementary issues of control (which has been reviewed within Vehicle System Dynamics previously) and monitoring (which has not previously been reviewed). The theory, concepts and implementation status are assessed in each case, from which the paper identifies the key trends and concludes with a forward look at what is likely to develop over the next years.