US Navy Studies on Alternative Fuel Sources and Power and Propulsion Methods for Surface Combatants and Amphibious Warfare Ships

The US Navy has been studying the technical and cost impacts associated with the availability and cost of fossil fuel contrasted with nuclear energy alternatives for surface combatants and amphibious warfare ships. Over the past 2 years these efforts have grown in maturity to examine the tactical and strategic implications of our Navy's dependence on fossil fuels from technical, economic, and military perspectives. This paper will present three major topics:

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  Background research on alternative energy sources.
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  A survey discussion of current and future power and propulsion system technologies.
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  An overview of principal Naval Sea Systems Command studies on the integration of alternative power and propulsion system technologies into notional surface combatants, submarines, and amphibious warfare ships.

Given the US Navy's dependence on fossil fuels and the expected increase in cost and reduced availability of fossil fuel, propulsion system investment decisions made today will have a profound impact on the future tactical and strategic roles of the US Navy surface fleet. This paper lays the foundation for providing robust and flexible technology decision opportunities for the Navy's future.     

Waterway traffic analysis of the Chicago River and lock

The vessel-carrying capacity of the Chicago River, Illinois, is restricted by a lock. separating the river from Lake Michigan. Currently, vessels passing through the lock experience long delays during summer months. An investigation and analysis of this system determined that although the system is now generally operating below capacity, the peak periods during summer weekends do approach capacity, and the situation is likely to deteriorate in the future. In addition, the river and lock have safety and traffic conflict problems that need attention. Recommendations to mitigate these problems are described.     

Stability Criteria for Automobile-Trailer Combinations

The characteristic equation for a simple automobile-trailer combination is analyzed, revealing the parameter groups which are important in determining the stability characteristics. Application of Routh's method results in separate criteria for oscillatory and non-oscillatory criteria which can be evaluated algebraically, and which can also be displayed graphically showing a region of stability on a two-dimensional plot. The stability region is bounded by limits of oscillatory and non-oscillatory stability, and the evaluation of a specific case corresponds to the location of a point relative to the boundaries.     

Rethinking maritime privatization in Africa

While recognizing the need for increased participation of the private sector in the maritime industry of developing countries, there is a need to go beyond the call for privatization in terms of mere change of ownership from state to private sector as the only solution to the inefficiency of the maritime industry in developing countries. This limited understanding of the maritime problems of these countries abounds in the literature on maritime privatization. This study departs from this approach and focuses on the political economy of the maritime industry, and suggests that maritime privatization will not necessarily result in increased efficiency of the divested maritime enterprises. Rather, it argues that maritime problems in these countries have less to do with ownership than with the structural constraints in world shipping together with internal management and local ~olitics. The maritime industrv in West and Central Africa is used as a case studv. and recommendations such as selective privatization, 'programme contract', and most importantly, corporatization, are suggested as alternative strategies that could enhance maritime privatization and the development of the maritime industry in developing countries.     

The port-routeing behaviour of short-sea ship operators; theory and practice

This paper provides an interpretation of a port-routeing pattern of short-sea shipping services which has emerged in recent years. After basic definition. a macro theory of port routeing is presented together with an examination of the business environment of operation. Greater refinement is subsequently added with reference to the behavioural characteristics displayed by a number of individual ship operating companies in port routeing as revealed by a series of in-depth interviews. Specific illustration is provided by the Great Britian-Frances market and the paper concludes by suggesting some factors to influence the development of the future port-routeing pattern.     

The need for a structured policy towards reducing human-factor errors in marine accidents

The paper questions why so little attention has been given to the primary control centre of a merchant ship, namely the bridge, when so many accidents at sea are caused by 'human error'. The paper then suggests that there is a need for a policy which will draw the various threads of the problem together in a form suitable for international discussion and even legislation. The identified areas are those of training, bridge design, psychology and marine traffic discipline.     

Dynamics of Pneumatic Tire Vehicles with Connected Suspension Systems

A vehicle model, with 10 degrees of freedom is used to investigate the skidding conditions of any wheel of the vehicle in motion. Equations for the load transfer and equations for the pneumatic tire spring and shock absorber are derived. Parameters such as gradual cornering, U-curve cornering, the wavy road surface of different wave lengths and cases of independent and connected suspension systems are inputs to the system. The tire calculated forces and their corresponding maximum resistance forces are the outputs of the systems. A connected suspension system is found to resist skidding better than the independent suspension system. The system is non-linear, and numerical solutions are obtained.