Crane Productivity Research Articles

A quay crane productivity predictive model for building accurate quay crane schedules

ABSTRACT The efficient management of maritime logistics operations improves the performance of global supply chains. An important issue in container terminal operations is the scheduling of quay cranes (QCs), which is affected by the productivity rate of QCs. This productivity rate depends on the type of tasks to be completed by QCs on any given vessel. In this paper, we propose an artificial neural network (ANN) model with a variable neighbourhood search (VNS) as a training algorithm to build a productivity rate predictive model. This model considers several predictors depending on the type of containers in the vessel and the expected equipment downtime. We also study how QC scheduling is impacted by the productivity rate of QCs. The proposed predictive model and a moving average model are used to estimate the productivity rate, which is then taken as input to the QC scheduling optimisation model. Results show that when the proposed predictive model is used, QC schedules are closer to those generated using real data obtained from our container terminal partner.

Improving the Competitiveness of Crane Production by Impression Management

The adoption of aspects of impression management to improve the competitiveness of manufacturing is discussed. As a practical example, a crane with a cabin simulator is considered, for use at trade shows and other venues.

Dynamic programming algorithms for the general quay crane double-cycling problem with internal-reshuffles

High utilization of quay cranes is a major objective pursued by seaport terminal managers. Double-cycling technique has been shown to be effective in practice. Complicated with reshuffle operations, the productivity of quay cranes could be further improved, but the problem complexity increases as a side-effect. This paper studies a double-cycling quay crane scheduling problem in which reshuffle containers can be handled internally on the vessel. For this problem, no exact algorithm exists in the literature. We present a dynamic programming approach to optimally solve the problem. Our algorithm runs in polynomial time when the number of container stacks is fixed. We also extend our proposed optimal algorithm to the general case where hatch covers are involved.

Coordinated optimization of equipment operations in a container terminal

Increasing international maritime transport drives the need for efficient container terminals. The speed at which containers can be processed through a terminal is an important performance indicator. In particular, the productivity of the quay cranes (QCs) determines the performance of a container terminal; hence QC scheduling has received considerable attention. This article develops a comprehensive model to represent the waterside operations of a container terminal. Waterside operations comprise single and twinlift handling of containers by QCs, automated guided vehicles and yard cranes. In common practice, an uncoordinated scheduling heuristic is used to dispatch the equipment operating on a terminal. Here, uncoordinated means that the different machines that operate in the container terminal seek optimal productivity solely considering their own respective stage. By contrast, our model provides a coordinated schedule in which operations of all terminal equipment can be considered at once to achieve productivity closer to the QC optimal. The model takes the form of a hybrid flow shop (HFS) with novel features for bi-directional flows and job pairing. The former enables jobs to move freely through the HFS in both directions; the latter constrains certain jobs to be performed simultaneously by a single machine. We solve the coordinated model by means of a tailored simulated annealing (SA) algorithm that balances solution quality and computational time. We empirically study time-bounded variants of SA and compare them with a branch-and-bound algorithm. We show that our approach can produce coordinated schedules for a terminal with up to eight QCs in near real time.

The reproductive success of sandhill cranes in midwestern landscapes

ABSTRACTA number of wildlife species have recovered from the brink of extinction to flourish and, in some cases, even become a commonly recognized urban species (e.g., Canada goose [Branta canadensis]). Broadly extirpated from much of their historical range in North America, the sandhill crane (Antigone canadensis) demonstrated this potential for population recovery. The trajectory of the eastern population of greater sandhill cranes is remarkable—perhaps as many as 90,000 cranes now occur throughout the same Great Lakes states that reported only dozens of birds less than a century ago. However, understanding future population growth of the species remains uncertain because breeding birds are increasingly exposed to the pressures of urban sprawl and a changing agricultural landscape. From 2009 to 2014 we investigated the survival of sandhill crane nests and young up to 11 weeks of age (the point at which they are capable of flight) in the core of the eastern population's range in central Wisconsin and at its peripheral extent in a rapidly developing urban region of northeastern Illinois, USA. We located crane nests via systematic surveys on foot and from helicopters, we then radio‐tagged the young and monitored them until they died or were capable to sustained flight. Overall, young were more likely to hatch from nests in Illinois (60%) than in central Wisconsin (46%), regardless of differences in land cover surrounding the nest site. In contrast, the survivorship of young was positively correlated with urban land cover in both regions but higher in central Wisconsin (54%) than in northeast Illinois (27%). Overall, the probability of producing young was greater in landscapes with more urban development, regardless of region. We suggest that differences in predator composition, predator behavior, and crane density between rural and urban areas is the primary reason for the difference in crane productivity. Higher recruitment of sandhill cranes using urban landscapes may allow cranes to echo the population trajectory of urban Canada geese. We anticipate that sandhill cranes will continue to use urban landscapes, and likely expand their geographic range as breeding pairs benefit from the increased survivorship of young in those landscapes. © The Wildlife Society, 2019

The economic and environmental assessment on production stage of quayside crane

With the acceleration of globalization, trade between countries has become more and more frequent; as a kind of commonly used heavy lifting equipment, the influence of the quayside crane on environment during the production stage has attracted wide attention. In this paper, the world’s largest quayside crane manufacturer was selected as the study object. The environmental load of five workshops (NC pre-treatment workshop, assembling workshop, sand milling workshop, painting workshop and steel structure workshop) involved in the quayside crane (QC) production stage was studied by using the ReCiPe model; the normalized values of the 14 overall pollutants in each workshop were 1248.64, 576.75, 214.27, 85.26 and 76.69, respectively. The results showed that the sand milling workshop was the biggest electricity consumer of all processes. The sensitivity analysis revealed that the environmental pollution load was the most sensitive to the electricity consumption; the scenario analysis indicated that with the proportion of China’s renewable resources in the process of electricity generation becoming larger and larger, in comparison with that of in 2015, up to 2050, the quantity of PM 2.5 generated during the production process of QC will drop from 832 to 408 kg (high-speed development)/342 kg (low-speed development), and it is expected that the China’s haze problem could be effectively curbed in the future. Finally, the research results of this article also pointed out the direction for the future technical innovation of the QC industry.

Simultaneous Allocation of Berths and Quay Cranes under Discrete Berth Situation

This paper examines the simultaneous allocation of berths and quay cranes under discrete berth situation in container terminals. The berths of discrete type have been broadly applied in realistic production especially for the terminals whose berths are not aligned in a straight line. The typical features of such berths including wharf length constraints, water depth constraints, and berth-bound quay cranes have been considered in this paper. In contrast to the previous work which only deployed the number of quay cranes besides the assignment of berths, this paper assigns berths and quay cranes simultaneously. In addition, to better fit the realistic production, some practical features related to quay cranes including the interference between quay cranes, the berth-dependent productivity of quay cranes, and limited adjustments of the assigned quay cranes during operations have also been considered in this paper. An integer programming model is formulated for this problem, and a sub-gradient-based Lagrangian relaxation algorithm is proposed. A simple but efficient greedy insertion heuristics is developed to solve the decomposed primal problems to optimality. Based on actual data, numerical experiments are conducted to test the performance of the proposed algorithm.

Linear Programming Algorithm for Assembly Line Balancing in Crane Production

Crane has the characteristics of complex structure, large volume and weight. Crane production is widely used in fixed-point assembly. But in the fixed-point assembly process, there will be assembly inefficient, complex distribution, to be more products and other issues arise. Therefore, the assembly line balance is one of the important issues in planning efficient assembly lines. On the basis of fully understanding the crane production line, the linear programming method was used to establish the mathematical model which can fully reflect the relationship between the production elements of the production line in this paper. And then using Lingo software to optimize the production line balance solution, the assembly line achieve a smooth production and improve the production efficiency.

THE EFFECT OF MULTI-TRAILER SYSTEMS ON THE EFFICIENCY OF CONTAINER MOVEMENTS BETWEEN THE SHIP AND THE STACKS AT THE DURBAN CONTAINER TERMINAL

Tractor-trailer units are the primary horizontal transport medium between the ship and the stacking area in container ports, and their efficient operation has a strong influence on loading and unloading rates. This paper presents a comparative study of the vessel loading and unloading procedure at the Port of Durban for conventional tractor-trailer units versus short multi-trailer systems. A discrete event simulation approach was used to model the terminal’s operations using the two types of vehicles, and to analyse the effect on the terminal’s performance and operating costs. The results of the study showed that the current fleet of tractor-trailer units can be replaced by a fleet of multi-trailer systems capable of carrying four twenty-foot equivalent units (TEUs) each, resulting in equivalent quay crane productivity while reducing the terminal’s operating cost per shift for the horizontal transport subsystem.

An improving agent-based engineering strategy for minimizing unproductive situations of cranes in a rail–rail transshipment yard

Nowadays, seaports seek to achieve a better massification (massive transportation of containers) share of their hinterland transport by promoting rail and river connections in order to more rapidly evacuate increasing container traffic shipped by sea and to avoid landside congestion. The attractiveness of a seaport to shipping enterprises depends not only on its reliability and nautical qualities but also on its massified hinterland connection capacity. Contrary to what has been observed in Europe, the massification share of Le Havre seaport has stagnated in recent years. To overcome this situation, Le Havre Port Authority is putting into service a multimodal hub terminal linked only with massified modes. In this study, we focus on rail–rail transshipment of this new terminal, specifically on minimizing unproductive situations of cranes to improve crane productivity and to speed up freight train processing. To this end, an improving agent-based engineering strategy called the “crane anti-collision strategy” is proposed and tested using multi-method simulation software (Anylogic). In a numerical study, the simulation results reveal that our developed model is very satisfactory and outperforms other existing simulation models.

Improved formulations and an Adaptive Large Neighborhood Search heuristic for the integrated berth allocation and quay crane assignment problem

This paper focuses on the integrated berth allocation and quay crane assignment problem in container terminals. We consider the decrease in the marginal productivity of quay cranes and the increase in handling time due to deviation from the desired position. We consider a continuous berth, discretized in small equal-sized sections. A number of enhancements over the state-of-the-art formulation and an Adaptive Large Neighborhood Search (ALNS) heuristic are presented. Computational results reveal that the enhancements improve many of the best-known bounds, and the ALNS outperforms the state-of-the-art heuristics for many instances. We also conduct further analysis on a new larger benchmark.

Scheduling of Different Automated Yard Crane Systems at Container Terminals

In this work, different variants of a branch-and-bound procedure for yard crane scheduling at seaport container terminals and their effect on the terminal’s performance are studied. In particular, this work investigates the level of detail needed to take the exact crane characteristics, e.g., movements and crane interference, into account in the scheduling algorithm. This is examined for four different automated yard crane systems with one or more cranes that operate on rectangular yard blocks with transfer positions at both ends of the block and with the yard blocks arranged orthogonally to the quay. Using a simulation model with realistic scenario data and an automated guided vehicles system for horizontal transport, the results are compared with respect to different key performance indicators, e.g., yard crane productivity and average lateness of jobs. It turns out that especially the consideration of crane interference leads to significant improvements in yard crane productivity. As a result of the long computation times for some crane systems that render the practical application of the algorithm difficult, an approximation procedure is also developed that generates good results in reasonable time and hence allows for real-time application at a container terminal.

Containership port time: The bay time factor

Containership size has been increasing in length, width (beam), and height. The introduction of Ultra Large Containerships results in a much larger number of containers stowed in a cargo bay. The objective of this paper is to determine the impact of the increasing containership bay size on the economies of scale at berth. We develop the concept of bay time, the amount of time it takes to load and discharge the largest cargo bay of a containership based on bay size, in order to determine the minimum amount of time it takes to discharge and load a containership. The analysis establishes that bay time is the foundation and critical path of the minimum amount of time a containership must stay at berth and in port. The study notes that, inherently, an increase in containership bay size involves diseconomies of scale in cargo handling operations, at a given level of gantry crane productivity. We find that there are increasing diseconomies of scale for large containerships at berth. The study also establishes that: as beam/bay size increases, the average cargo handling time of two bays increases by an average of 4.5 h at any productivity level. Bay time declines as crane productivity increases up to the crane’s technological constraint. Furthermore, the larger the beam/bay, the larger the marginal benefits when productivity increases. The diseconomies of scale are stable and predictable at every gantry crane productivity level. The study recommends using bay time as the fundamental measure for containership performance at berth and in port, as well as for voyage planning.

Active Way of Clearing of Fluctuations of Freight after a Stop of the Bridge Crane

Разработан активный способ гашения остаточных маятниковых колебаний груза после остановки мостового крана путем перемещений точки подвеса груза с помощью гидроцилиндров. Разработанный способ позволяет обеспечить сокращение времени остаточных маятниковых колебаний груза. В результате повышается производительность крана.

Research into container reshuffling and stacking problems in container terminal yards

Container stacking and reshuffling are important issues in the management of operations in a container terminal. Minimizing the number of reshuffles can increase productivity of the yard cranes and the efficiency of the terminal. In this research, the authors improve the existing static reshuffling model, develop five effective heuristics, and analyze the performance of these algorithms. A discrete-event simulation model is developed to animate the stacking, retrieving, and reshuffling operations and to test the performance of the proposed heuristics and their extended versions in a dynamic environment with arrivals and retrievals of containers. The experimental results for the static problem show that the improved model can solve the reshuffling problem more quickly than the existing model and the proposed extended heuristics are superior to the existing ones. The experimental results for the dynamic problem show that the results of the extended versions of the five proposed heuristics are superior or similar to the best results of the existing heuristics and consume very little time.

An Integrated Quay Crane Assignment and Scheduling Problem

As maritime container transport is developing rapidly, the need arises for efficient operations at container terminals. One of the most important determinants of container handling efficiency is the productivity of quay cranes, which are responsible for unloading and loading operations for container vessels. For this reason, the Quay Crane Assignment Problem (QCAP) and the Quay Crane Scheduling Problem (QCSP) have received increasing attention in the literature and the present paper deals with the integration of these interrelated problems. A formulation is developed for the Quay Crane Assignment and Scheduling Problem (QCASP), which accounts for crane positioning conditions and a Genetic Algorithm (GA) is developed to solve the QCASP. Both the model formulation and the solution methodology are presented in detail and computational analysis is conducted in order to evaluate the performance of the proposed GA. The results obtained from the GA are compared with the results from an exact technique, thus providing complete information about the performance of the heuristic in terms of solution quality.

Research on the Decision-Making Model of Container Cranes' Renewal

Container cranes renewal is an important issue related to the port production efficiency. Considered of characteristics of container crane production, the author use the method of mathematical programming and analyze its renewal decision, establish a renewal decision-making model based on container crane life cycle management, and provide an example analysis. The research achievement can be used for diagnosis and assessment of container crane and other port equipment.

Comparing Manned and Automated Horizontal Handling Equipment at Container Terminals

The choice to use horizontal handling transport in automated container terminals is not fully consistent in comparison with the automation of stacking cranes at the storage yard. Often the decision of whether to use an automated system between the berth and the yard area is not clear, and terminal operators tend not to use automated systems. The goal of this paper is to provide an economic analysis to determine under which conditions automated horizontal transport is more efficient than a semiautomated system. The study provided several simulation models to calculate the optimal equipment necessary to connect storage and berth subsystems in a maritime container terminal in fully automated and semiautomated scenarios. Data from the semiautomated container terminal at the Port of Barcelona, Spain, were used. In addition to the cost analysis, guidelines on the best alternative, considering labor costs, throughput movements per quay crane and year, and quay crane productivity are provided.

Quay Cranes in Container Terminals

Container's transport over the world plays a major logistics role in the contemporary global economy. Seaports and their container terminals represent an important function in the logistics chain. The transshipment speed of containers in the container terminal is the significant factor participating in the overall transport time. Quay cranes served as one of the essential elements of the trans-hipment containers in the container terminal. This paper deals with quay cranes, comparing particular specific crane's components. Furthermore, the paper carries out an analysis of the optimal quay crane productivity, with regard to contemporary requirements. At the end of the article requirements for the future development of the quay cranes are submitted.

Using the truck appointment system to improve yard efficiency in container terminals

This article considers the effectiveness of a truck appointment system in improving yard efficiency in a container terminal. This research uses the truck appointment information obtained from an appointment system to improve import container retrieval operation and reduce container rehandles by adopting an advanced container location assignment algorithm. By reducing container rehandles, the terminal could improve yard crane productivity and reduce truck transaction time. A hybrid approach of simulation and queuing theory was developed to model the container retrieval operation and estimate the crane productivity and truck turn-time. Various configurations of the truck appointment system are modeled to investigate how those factors affect the effectiveness of the truck information. The research results illustrate a clear benefit for terminals utilizing a truck appointment system to manage their yard operation. Reducing the duration of the appointment time window or increasing the appointment lead time could further enhance system performance. Furthermore, the truck information is still effective in improving system efficiency, even if a good portion of trucks miss their appointments.