Ship productivity as a measure of maritime performance

Ship and fleet productivity have been discussed increasingly as performance measures in recent years, but productivity has not been defined precisely as it relates to the maritime industry. This article offers definitions from some key terms that can clarify the concept of productivity and thus make it more usable as an analytical tool for steamship management.     

Public transit subsidies, output effect and total factor productivity

This paper extends previous works on total factor productivity decomposition when firms receive both operating and capital subsidies. It shows that previous works considered either the lump-sum or substitution effects of these subsidies but not together. Using constrained cost minimization as the framework it offers formal proofs to show that cost increases are inevitable if the total effects of the subsidies are considered, and that total factor productivity growth results from increasing amounts of subsidies under economies of scale and in the absence of technical change. Applications of the decomposition equations derived to a sample of transit systems finds near constant returns to scale and negative contributions of these subsidies to total factor productivity growth. Technical change reverses this decline and results in total factor productivity growth. Further, it finds that the lump-sum effects of the subsidies reduce total factor productivity more than does the substitution effect.     

Cargo handling productivity. Part 2. The findings

This is the second of two papers on cargo handling productivity presenting the results of the model developed int he first [1] which had been designed to test a productivity measurement method with cross-sectional empirical data. Four productivity measures were employed. Two related cargo handling to time, with labour brought into the analysis as an independent variable. The third productivity measure expressed total throughput as an aspect of labour productivity, while the final measure was a full productivity index developed by relating output to both capital and labour.

The productivity measurement technique demonstrated that this method can be used for cross-sectional studies and can cope with and allow for variation in non-controllable extraneous factors, thus proving useful for policy decision-makers in shipping lines and/or port authorities.

This paper presents the results of the prodictivity analysis for which the analytical design was decribed in Part 1. The first section briefly restates the productivity indices developed. The principal results and tests on these measures are present in Section 2 with conclusion following in Section 3.     

The Port of Melbourne Authority's pricing policy: its efficiency and distribution implications

The objective of this paper is investigate the extent to which the new (revised) pricing policy has improved the level of efficiency at the Port of Melbourne and to assess the contributions of the underlying factors of port efficiency. Further, it attempts to examine the distribution implications of the pricing policy between the major port users (i.e. shipowners and shippers) and its revenue implication for the Port of Melbourne. Using a conceptual framework derived from economic theories, in-house data and responses from the port users, the study reveals that the efficiency impact has been considerable and varied between berths; land transport links and crane productivity improvements were the major factors of the port's overall efficiency; the initial losers have been the shipowners and initial gainers the shippers; however, the gains have been limited and in some cases have been offset by the introduction of higher port service charges; in the long run it is likely that the shipowners and shippers' situations will be unchanged while the Port of Melbourne will lose revenue due to improvements in berth productivity uncompensated by greater traffic volume.     

Productivity change of the Spanish Port System: impact of the economic crisis

ABSTRACT

The main goal of this study was to assess the impact of the economic crisis on the productivity growth of the Spanish Port System (SPS). The Malmquist Productivity Index (MPI) was estimated for the 28 Port Authorities of the SPS, for a ‘non-crisis period’ (2005–2008) and a ‘crisis period’ (2008–2011). From a policy perspective, the MPI is a very useful approach for assessing the productivity change because it can be decomposed into the catching-up index and the frontier productivity index. The results showed that the economic crisis did not impact all of the Spanish Port Authorities equally. Some Port Authorities presented higher productivity growth during the crisis period than in the non-crisis period. Further analysis by the Mann–Whitney test revealed that Port Authority investments and productivity growth were statistically related. Information provided by this study may be very useful for stakeholders and decision-makers, in terms of long-term strategic planning and improving the competitiveness of the SPS. The findings illustrate that the economic crisis should not be seen as an international tragedy, but as an opportunity to adapt port traffics and installations to new needs and market demands.     

LW350×1050N卧式螺旋沉降离心机参数选择及设计计算

螺旋沉降离心机具有分离因素高,能实现悬浮液的脱水、澄清、分级的过程,对分离物料的适应性强,单位生产能力的功耗低等特点.因而在工业上获得广泛应用.该文主要介绍卧式螺旋沉降离心机的工作原理和参数的选择,以及基础理论计算,包括生产能力的计算和转鼓壁厚的设计计算.     

A Few observations on productivity in seaports

In this paper, the author describes and discusses the cargo-handling productivity in European seaports and the various factors which may influence it. He focuses on the effects of the 'port revolution' which began in the years of reconstruction following the end of the Second World War. This involved the introduction of new (and usually mechanized) cargo-handling techniques which die so much to change the traditional approach to shipping and port operations. He goes on to assess the importance of these developments for the Port of Antwerp, stressing particularly the organization of dock labour, the physical lay-out of the port, and the type and extent of use of technical equipment. He concludes that big differences exist in port productivity between continental European ports, due to the degree to which they have been affected by, and, more importantly perhaps, responded to, the changes of the past few decades.     

Productivity functions as a managerial tool in Israeli ports

Research was undertaken with the goal of developing productivity functions that explain the changes in the productivity is Israeli ports by means of changes in various explanatory factors. Productivity is measured by an engineering aproach, i.e. actual performance is measured against engineering standards. Partial productivity indices are worked out for each factor separately and aggregated to yield a total productivity index, which is calculated in two ways: one uses updated standatds as a basis of comparison (giving local productivity) and the second uses comparison standards of a basic period (yielding comparative productivity figures). The paper examines the theories and assumptions within the ports of Israel, which offer a good example for analysing productivity because they are characterized by significant developments in the quality and quantity of inputs. The ports have experienced many technological developments that have had a crucial effect on the nature of their activity. The explanatory factors were examined, out of which were chosen those in each family that corelate best with productivity. A linear programming model is generated for developing productivity functions with an objective function of minimum deviations between calculated and actual productivity. The constranints in this model ensure that the coeficients remain within ranges that are meaningful with regard to the problem uner examination. Productivity measures based on the engineering approach and the productivity functions developed herein can be engineering approach and the productivity functions developed herein can be utilized as aids in managing ports and in determining what steps should be taken to improve productivity.     

The British port transport industry part 2. Employment, working practices and productivity

The abolition of the national Dock Labour Scheme presented with the oppurtunity radically to transform their cargo handling operations. Port employers have seized this oppurtunity and introduced radical changes to workforce compositions, their skills, work practices, and employee relations. The main factor behind these changes has been the desire of operation to minimize labour costs and maximize labour utilization in order to amintain traffic volume and competitive advantage. The short-term effect has been to improve productivity and profitablity(at least for the major port authorities), but it has also produced iinstablity in employee relations ans may in the long term prove counter productive>     

如何确定耙吸船最佳装舱时间

提高耙吸船开挖密实粉细砂的施工效率是疏浚工程界不断探索的问题,而采用最佳装舱时间是提高耙吸船挖砂效率最有效的方法之一。结合锦州港301泊位工程港池粉细砂的疏浚施工,通过对有效载重曲线和小时效率曲线的分析,简要介绍最佳装舱时间的计算。     

A maritime productivity study 1859-1919

This is one of two papers designed to test the ability of a theoretical model of productivity measurement [1] with times series empirical data. The analysis was able to identify trends in productivity growth for sailing ships and stcamships. scparating long and short run components . One of the interesting features of the findings is that the long run growth rate is the same for both sailing and steamships. Although sail and steam appear to be two unique technologies, it is found that technologica progress is evolutionary not revolutionary.

The techique using covariance analysis proved useful for times series productivity measurement.     

Prediction of steel plate deformation due to triangle heating using the inherent strain method

In a shipyard, line heating and triangle heating are two major processes carried out by skilled workers to form curved plates in various shapes under various heating conditions. There have been many studies on line heating, but triangle heating has rarely been studied owing to its complicated heating process with irregular multiheating paths and highly concentrated heat input. Triangle heating is the most labor-intensive job. Hence, it is essential for most shipyards to study the automation, as well as the improvement, of the triangle heating process in order to increase hull-forming productivity. In this study, a pioneering attempt to simulate triangle heating was made. A circular disk-spring model is proposed as an analysis model for the elastoplastic procedure of triangle heating, and the inherent strain method is also used to analyze the deformation of plates. The results of the simulation were compared with those of experiments and showed good agreement. It is shown that the present approach and the model used in this study are effective and efficient for simulating triangle heating for the steel plate forming process in shipbuilding.     

海洋生态系统及海岸工程生态影响预测模型研究进展

对海洋生态系统的研究已形成了以实验观测为基础、建立生态模型的方法。文章对已有的海洋生态模型研究成果进行了归纳总结,认为初级生产力模型是纯生态模型的主要发展方向,综合考虑物理生化作用的生态系统动力学模型将是未来海洋生态研究的必然趋势。同时,由于我国大规模海岸工程建设对近岸海域生态系统造成了较大影响,而相关的生态影响预测模型研究较少,为有效预测评价海岸工程建设对近岸海域生态系统的影响,进一步深入研究海岸工程建设对近岸海洋生态影响预测模型将显得尤为重要。     

The importance of polynyas, ice edges, and leads to marine mammals and birds

The correlation between areas of open water in ice-covered seas and increased biological productivity has been noted for some time. To date, most attention has been focused on larger polynyas, such as the Northeast Water and the Northwater. Although spectacular in their own right, these large polynyas represent only part of a vitally important continuum of biological productivity that varies significantly between geographic areas and ice habitats, that includes the multi-year pack of the polar ocean and small localized polynyas in annual ice. Surveys of the distribution and abundance of ringed seals in the Canadian Arctic Archipelago have shown differences in density that are correlated with the presence or absence of polynyas. There is also significant variation in the biological productivity of polynya areas of the Canadian High Arctic Archipelago and northern Greenland, all of which receive inflow from the polar basin. Long-term studies of polar bears and ringed seals in western Hudson Bay and the eastern Beaufort Sea show significant but dissimilar patterns of change in condition and reproductive rates between the two regions and suggest that fundamentally different climatic or oceanographic processes may be involved. Projections of climate models suggest that, if warming occurs, then the extent of ice cover in Hudson Bay may be among the first things affected. Long-term studies of polar bears and ringed seals in the eastern Beaufort Sea and Hudson Bay would suggest these two species to be suitable indicators of significant climatic or oceanographic changes in the marine ecosystem.     

重型绞吸挖泥船挖岩施工工艺优化

微风化岩具有强度高、裂隙少的特点,绞吸挖泥船在挖掘时产能较低。为提高绞吸船施工产能、降低施工成本,以大连大窑湾航道疏浚工程为例,对新建出厂的自航式重型绞吸挖泥船“天鲲号”开挖坚硬微风化岩的施工技术进行研究。分析绞刀姿态、刀齿损耗以及横移摆动对产能的影响,从而优化施工工艺。结果表明,“天鲲号”在挖掘硬微风化岩时的产能得到有效提高。     

Evaluating seaport policy alternatives: a simulation study of terminal leasing policy and system performance

The competitive characteristics of the North American seaport industry have, in theory, been causally linked to excess investment and low terminal throughput productivity. This paper empirically examines the link between seaport authority container terminal leasing policy and throughput productivity. Recent advances in inventory theory applied to service industries suggest the pooling of demand uncertainty can yield lower costs without sacrificing customer service. This concept is applied to a container seaport using simulation. The effort compares key output measures from a realistic base case model of the seaport to those generated by an alternative terminal leasing policy. It is shown that the pooling of demand in a common-user seaport reduces total vessel time in port by 17.1% with no reduction in TEU throughput. Throughput productivity is improved for the highest capacity terminals, while lower capacity terminals are made available for additional users or alternative uses.     

Evaluating seaport policy alternatives: a simulation study of terminal leasing policy and system performance

The competitive characteristics of the North American seaport industry have, in theory, been causally linked to excess investment and low terminal throughput productivity. This paper empirically examines the link between seaport authority container terminal leasing policy and throughput productivity. Recent advances in inventory theory applied to service industries suggest the pooling of demand uncertainty can yield lower costs without sacrificing customer service. This concept is applied to a container seaport using simulation. The effort compares key output measures from a realistic base case model of the seaport to those generated by an alternative terminal leasing policy. It is shown that the pooling of demand in a common-user seaport reduces total vessel time in port by 17.1% with no reduction in TEU throughput. Throughput productivity is improved for the highest capacity terminals, while lower capacity terminals are made available for additional users or alternative uses.     

Ecology of bottom ice algae: II. Dynamics, distributions and productivity

Spring blooms of bottom ice algae are a common feature of landfast congelation ice in polar regions. Because ice algae are usually associated with a substrate, their population dynamics can be followed with considerable confidence. Although ice algal dynamics are closely related to irradiance, their dynamics and distributions are influenced by other abiotic and biotic factors. Ice algal abundance varies horizontally over all scales examined. Factors such as grazing and nutrient availability may contribute to local and geographic differences. Loss terms for most sea ice assemblages are largely unquantified. Ice algal biomass is most concentrated near the ice-water interface in spring.Environmental factors affecting ice algal abundance and productivity are considered here, emphasizing recent results from several well-studied sites. Biomass accumulation, growth rates and productivity have been documented for spring blooms of bottom interstitial and sub-ice assemblages. On an areal basis biomass accumulation in bottom ice assemblages can be comparable with planktonic systems. At low ambient temperatures and irradiances average specific growth rates (≤ 0.25 d⁻¹) and production rates (≤ 1.0 mg C mg Chl⁻¹ h⁻¹) for ice algae are low. Current methods of measuring productivity are compared. Results are consistently low but variable with little systematic difference among them. At present, apparent differences in productivity between bottom ice assemblages in the Arctic and Antarctic, or among different antarctic assemblages, are so confounded by methodological and other sources of variability that no firm differences can be detected.     

Container terminal productivity: a perspective

The increasing competitiveness of the marine transportation industry has brought about demands that container terminal productivity be improved. MARAD, in cooperation with the National Research Council, has responded by developing a number of quantitative measurements for container terminal productivity. In this paper we discuss the problems and prospects of using such measurements to estimate or compare the productivity of terminals or ports. Because physical or institutional factors, or a combination of the two, act to limit the productivity of every container terminal, quantitative productivity comparisons among terminals or ports may lead to misplaced efforts to improve the productivity of particular operational elements in piecemeal fashion. By contrast, a sensible strategy for managing productivity would involve the linking of productivity and cost data, so that existing productivity constraints can be intelligently shifted from one area of operations to another.     

Exploring the effects of passenger rail franchising in Britain: Evidence from the first two rounds of franchising (1997-2008)

This paper provides an up-to-date review of the previous literature concerning the impact of passenger rail franchising on productivity and costs in Britain, and also presents important new evidence. In particular, the extension in time of previously-used datasets offers the first opportunity to study the impacts of re-franchising. The previous literature emphasised the failure of franchising to produce sustained productivity gains, with a sharp deterioration in productivity after 2000. The new evidence presented offers a somewhat more positive view of the British experience. It suggests that part of what was previously considered to be falling productivity may in fact be due to exogenous changes in diesel prices. Further, new data suggests that the recent increases in costs have resulted in higher quality of service. Finally, competitive re-franchising, and the associated unwinding of short-term management and re-negotiated contracts, seems to have led to improvements in productivity between 2006 and 2008. Nevertheless, it remains the case that passenger rail franchising in Britain has failed to reduce costs in the way experienced in many other industries and in rail in other European countries. The evidence is that somewhat larger franchises, avoiding overlapping and optimising train density and length, should reduce costs. We also speculate that the major increase in wages and conditions of staff might be moderated by longer franchises, although that remains to be proved. This re-appraisal of the British case is important in the context of the wider international interest in the use of franchising in passenger rail, and its relevance to the current review of ways of introducing competition into the domestic rail passenger market in Europe.