Port competitiveness in container traffic from an internal point of view: the experience of the Port of Algeciras Bay

The objective of this article is to analyse the factors that affect port competitiveness from the perspective of the agents and companies that operate in one of the Mediterranean ports most active in container traffic: the Port of Algeciras Bay (PAB). It is essential to understand the perspective of the suppliers of port services, in order to apply the necessary judgment when formulating policies to strengthen the competitive position of a port. The model selected to meet the objective outlined is based on the ‘extended diamond’ of Porter. The universe for the study comprises all the institutions and companies involved in the containerization process in the Port of Algeciras Bay. Within this methodology, two procedures are utilised. First, from the quantitative perspective, a survey has been conducted to obtain responses to two groups of questions, one dealing with situation and the other with perceptions. Second, and from a qualitative perspective, several open interviews have been conducted to corroborate the responses obtained to the questionnaire. From the data obtained in the survey, a model has been estimated that minimises the sum of the residuals in absolute value, utilizing the L1 regression; this model enables the competitive advantages and disadvantages of the PAB, from the point of view of the port operators, to be determined by an analysis of residuals. This analysis demonstrates that the variables representing greater competitive advantages are associated with trans-shipment, and with the maritime accessibility of the Port to vessels, whereas those generating greater disadvantages are associated with rail transport (which, according to those surveyed, has resulted in the diversion of significant volumes of traffic to other Spanish or European ports with better communications, particularly Valencia, Barcelona and Gioia-Tauro, and with the state of competition in container trans-shipment activities.     

A study on slamming pressure on a flat stiffened plate considering fluid–structure interaction

Normally, the design slamming pressure on the bottomof a semi-submersible-type floating rig is determined in a simple way using the relative speed obtained from an air-gap analysis. However, few studies have taken a thorough, robust, and deep-background approach to the estimation of design pressure. To investigate the slamming pressure on the bottom of a semi-submersible rig, a simplified deformable stiffened plate of a zero-degree deadrise angle is simulated using the nonlinear FEM software LS-DYNA, which can take the influence of fluid–structure interaction (FSI) into account. Various parametric studies are carried out to examine the effects of structural flexibility, coupling stiffness, mesh size, velocity, stiffener size, and air cushion. The pressure response on the plate by the coupling of fluid and structure is studied and the FSI effect of each parameter is discussed. Then, equivalent transient and static loads that result in the same maximum or permanent deformation as FSI are evaluated for design purposes through a series of parametric studies.     

The effects of slow steaming on the environmental performance in liner shipping

The environment issue is one of the significant challenges that the liner shipping industry has to face. The International Maritime Organization (IMO) has set a goal to reduce greenhouse gas (GHG) emissions from existing vessels by 20–50% by 2050 and develop the Energy Efficiency Operational Indicator (EEOI) as a measure for energy efficiency. To achieve this goal, IMO has suggested three basic approaches: the enlargement of vessel size, the reduction of voyage speed, and the application of new technologies. In recent times, liners have adopted slow steaming and decelerated the voyage speed to 15–18 knots on major routes. This is because slow steaming is helpful in reducing operating costs and GHG emissions. However, it also creates negative effects that influence the operating costs and the amount of GHG emissions at the same time.

This study started with the basic question: Is it true that as voyage speed reduces, the operating costs and CO₂ emissions can be reduced at the same time? If this is true, liners will definitely decelerate their voyage speed themselves as much as possible so that they can increase their profits and improve the level of environmental performance. However, if this is not true, then liners will concentrate just on increasing their profits by not considering environmental factors. This led the authors to set out three objectives: (1) to analyze the relationship between voyage speed and the amount of CO₂ emissions and to estimate the changes by slow steaming in liner shipping; (2) to analyze the relationship between voyage speed and the operating costs on a loop; and (3) to find the optimal voyage speed as a solution to maximize the reduction of CO₂ emissions at the lowest operating cost, thus satisfying the reduction target of IMO.     

Greenhouse gas mitigation supply curve for the United States for transport versus other sectors

To compare transportation greenhouse gas mitigation options with other sectors, we construct greenhouse gas mitigation supply curves of near-term technologies for all the major sectors of the US economy. Our findings indicate that motor vehicles and fuels are attractive candidates for reducing GHGs in the near and medium term. Transport technologies and fuels represent about half of the GHG mitigation options that have net-positive benefits – so-called “no regrets” strategies – and about 20% of the most cost-effective options to reduce GHGs to 10% below 1990 levels by 2030.     

Speed limit laws in America: The role of geography, mobility and ideology

Speed limits had been centralized at the federal level since 1974, until decisions were devolved to the states in 1995. However, the centralization debate has reemerged in recent years. This paper conducts the first econometric analysis of the determinants of speed limit laws and State reactions after the repeal. By using mobility, geographic and political variables, our results suggest that geography - which reflects private mobility needs and social preferences -, is one of the main factors influencing speed limit laws, together with political ideology. Furthermore, we identify the presence of regional and time diffusion effects. By presenting first evidence on policy determinants, we provide a better understanding of the formulation of the heterogeneity of speed limits in US and offer implications for the debate on centralization and decentralization of transport policy.     

Limitation of egg production in Calanus finmarchicus in the field: A stoichiometric analysis

The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5(n−3) (EPA) and 22:6(n−3) (DHA). However, an understanding of which substrates limit egg production in the natural environment has yet to be reached. The quantities of C, N, EPA and DHA ingested, derived from parental biomass, and invested in eggs by female Calanus finmarchicus during a 5-day incubation experiment were examined using stoichiometric theory to determine which substrate was limiting. The majority of each substrate was derived from parental biomass, and therefore the existing stoichiometric theory is developed to include this route of supply. The females were essentially devoid of lipid reserves, as evidenced by the lack of the storage fatty acids 20:1(n−9) and 22:1(n−11), and carbon limitation was predicted under most of the scenarios examined. Nitrogen limitation was only apparent when carbon and nitrogen utilisation efficiencies were assumed to be high (0.5) and low (0.4) respectively. PUFAs were assumed to be utilised with high efficiency (0.9), and were never predicted to limit production. This work highlights the need for a more detailed understanding of the maintenance requirements that marine copepods have for C, N, EPA, and DHA and hence the efficiencies with these substrates can be utilised for growth.     

Impact of proposed federal limits on US bagged food aid shipments: reduction in MSF carrier profits—a risk assessment 1

This paper is a stochastic risk simulation of the impact of proposed federal tonnage limits on US Maritime Security Fleet (MSF) bagged food aid shipments. Only MSF (i.e. federally subsidized carriers/vessels for war, or emergencies) and non-MSF US carriers (therefore, at competitive disadvantage) can compete for such shipments—representing an indirect subsidy to both groups. To compensate, US Congress proposed a financial penalty (loss of voyage subsidy) on MSF carriers for food aid above a certain limit. Accordingly, certain carriers will be policy 'winners' (non-MSF—larger food aid shipments), and others 'losers' (MSF). By simulating loss-minimizing economic behaviour by MSF carriers—using five stochastic factors—I obtain losses substantially below those claimed by the MSF owners.

Simulated annual-average MSF profits reduction is $3.5 million—within a large confidence interval; if no carriers surrender their subsidies (as claimed by MSF owners), a reduction of $6.0 million. Only 16% of annual MSF voyages are affected by a 2,500-ton limit (3%; 5,000-ton limit). Minimizing losses, 25 (of 41 affected) annual MSF voyages replace 38,000 tons of food aid with 23,000 tons of other cargo—forgoing $2.1 million in yearly direct subsidies. Two assumptions explain most of this simulated loss reduction.     

Impact of interviewing by proxy in travel survey conducted by telephone

Telephone‐interview surveys are a very efficient way of conducting large‐scale travel surveys. Recent advancements in computer technology have made it possible to improve upon the quality of data collected by telephone surveys through computerization of the entire sample‐control process, and through the direct recording of the collected data into a computer. Notwithstanding these technological advancements, potential sources of bias still exist, including the reliance on an adult member of the household to report the travel information of other household members. Travel data collected in a recent telephone interview survey in the Toronto region is used to examine this issue. The statistical tool used in the research was the Analysis of Variance (ANOVA) technique as implemented within the general linear model framework in SAS. The study‐results indicate that reliance on informants to provide travel information for non‐informant members of their respective households led to the underreporting of some categories of trips. These underreported trip categories were primarily segments of home‐based discretionary trips, and non home‐based trips. Since these latter two categories of trips are made primarily outside the morning peak period, estimated factors to adjust for their underreporting were time‐period sensitive. Further, the number of vehicles available to the household, gender, and driver license status respectively were also found to be strongly associated with the underreporting of trips and thus were important considerations in the determination of adjustment factors. Work and school trips were found not to be underreported, a not surprising result giving the almost daily repetitiveness of trips made for these purposes and hence the ability of the informant to provide relatively more precise information on them.     

Active Suspension Control to Improve Vehicle Ride and Handling

In practice most active vehicle suspension work can be traced to two sources, Lotus' modal control and Karnopp's skyhook damper. A model is developed which allows comparison of different active suspension control algorithms. The Lotus modal control algorithm is reviewed, and compared with Karnopp's skyhook damper. It is shown that a tight inner closed loop allows the Lotus algorithm to achieve the inertial damping described by Kamopp for a single comer or quarter car. It is suggested that to achieve simultaneously high inertial damping and good disturbance rejection an inner force loop is desirable. A vehicle control scheme is presented which combines the Lotus modal decomposition with Karnopp's skyhook damper, allowing nearly optimal ride and simultaneously permitting modification of vehicle handling properties.     

Single wheel hub motor failures and their impact on vehicle and driver behaviour

This research work studies the impact of single wheel hub motor failures on the dynamic behaviour of electric vehicles and the corresponding driver reactions. An experimental study in a moving-base driving simulator is conducted to analyse the influence of single wheel hub motor failures for motorway speeds. Driver reaction times are derived from the measured data and discussed in their experimental context. The failure is rated objectively on the dynamic behaviour of the vehicle and compared to the subjective evaluation. Findings indicate that critical traffic situations impairing traffic safety can occur for motorway speeds. Clear counteractions by the drivers had to be taken.