The effects of US shipping regulation on specific aspects of liner conference operation

This paper is the first of two articles by J. E. Davies which seek to explore the incongruities of the USA's current regulatory system. The second paper will cover the overall economic impact of the USA's insistence on open conferences in its trades, whilst the first concentrates on the effects of US regulation on specific aspects of the operation of linear conferences.     

The compressive behavior of advanced double hull structure—A review of current research at David Taylor

It has long been recognized that the compressive behavior of primary ship structural components plays a vital role in the design of surface ship hulls. This is equally as true for the new advanced double hull concept as it is for the more conventional surface ship configurations. What is different, however, is the nature of the structural mechanics phenomena which must be addressed due to the double hull's more radical departure from conventional design and construction practices. With increasing interest and attention being shown in this new concept, the David Taylor Model Basin has over the past few years initiated a number of research efforts which have and are continuing to address various aspects of the behavior of double hulls and their components to primary compressive loadings. These studies have as their ultimate goal the development of practical, user oriented design methods for double hull structure and as such currently focus on more approximate, rather than mathematically rigorous, approaches to the various structural phenomena being considered. This paper is in essence a progress report on a selected number of these efforts and describes the results achieved to date as well as the ongoing efforts and those planned for the future. This report focuses primarily on three recent studies: (1) a preliminary look at the relative significance of local versus general instability failure of double hull structure; (2) small scale experimental analysis of double hull sections using rigid vinyl modelling; and (3) the application of beam-on-elastic-foundation analysis methods for high aspect stiffened plates as it relates to double hull structure. In addition to these major topics, the report also includes a brief discussion of other ongoing and planned efforts relevant to the advanced double hull.     

Wheel/Rail Contact: Geometrical Study*

Before trying to ascertain the precise nature of the Wheel-Rail contact (internal stresses and strains, wear and friction, security against a derailment, dynamic behaviour of the vehicle, etc.) the geometrical problem must necessarily be solved. That is, for each position of the wheelset (this is defined by 6 parameters, of which only 4 are independent) the two dependent parameters and the coordinates of the points of contact of each wheel, and rail must be obtained. A new method is proposed of obtaining the spatial position of a wheelset with reference to the rails, from the most general point of view.     

Rail freight transportation: A review of recent optimization models for train routing and empty car distribution

This paper describes two types of rail transportation problems in detail. These are train routing and makeup, and empty car distribution problems. Some of the recent optimization models which address these problems are reviewed and the areas for potential improvements in rail transportation literature are identified. The type of interactions which exist between routing, makeup, and empty car distribution decisions are highlighted and potential areas for future research are identified.     

An empirical comparison of disaggregate category and regression trip generation analysis techniques

Category and regression household trip generation analysis techniques were compared and contrasted. The comparative research was facilitated through a discussion that revealed the interchangeability of two methods of calibrating a category model. While the cell mean method is simple to implement, it does not readily yield statistical indexes for comparison with regression models. The general linear model analysis of variance (GLANOVA) readily provides statistical indexes for the comparison of category and regression trip generation models, and it produces identical empirical results to the simpler cell mean approach of calibrating a category model.The empirical comparison supports the widespread use of category models for trip generation analysis in transportation planning studies. It was found that regression and category models yielded equivalent results for typical planning applications at the district level of aggregation. In addition, both techniques estimated overall trip rate with equal accuracy in the calibration phase, and the two approaches were indistinguishable with respect to sample size sensitivity. However, households with extremely large trip rates were underestimated to a greater degree by category models than regression models. This tendency, in turn, resulted in larger calibration coefficients of determination for regression models. Since the cell mean method of calibrating a model is simpler and easier to understand than a regression model representation, category models can be recommended over regression models for planning studies.     

Shift-share analysis and port geography: a New England example

This paper demonstrates the validity of relative shift technique toward aiding the port geographer/planner in decision-making. The technique can be applied with a minimal of effort and yield diagnostic information concerning port commodity flows. A broad overview of New England's port facilities is presented, and the technique is then applied to an individual port, Boston.     

Labour relations and the transfer of the Panama Canal[1]

The international maritime community is concerned about Panama's preparedness to undertake the responsibility of what many consider to be the world's greatest maritime asset, the Panama Canal. In accordance with treaty provisions, the longer within the dominion of the U.S. government and its attendant regulatory framework and policies. To a great extent, Panama's efforts to prepare for the transfer thus far have been driven by its objective of a seamless transfer, whereby the status quo (meaning the Canal's existing institutional and organizational framework and attendant policies and procedures) would be preserved as much as possible. This would assure the maritime community that it can expect the same service and cost standards traditionally enjoyed under the Panama Canal Commission's stewardship. Still of great concern, however, is the continued reliability and productivity of the Canal's labour force; the Canal's reliability and efficient performance in the past is often attributed to its history of harmonious labour management relations. This article addresses some of the critical labour relations issues that will need to be considered even if Panama's status quo objective for the transfer is achieved.     

Facing the challenge of the future by strategic planning for public transport in Germany

Dramatic deteriorations in the future development of demographic and socio-economic factors having a decisive impact on public transport demand in 2000 - 2030 are predicted. How can a reasonable public transport service be maintained under these changing conditions? Depending on the entrepreneurial objectives defined individually by each public transport company a range of strategic actions must be taken in the field of offer and performance: Advancing strategies, consolidation strategies and defensive strategies are discussed with the stress laid on improving service in order to attract more ridership.