Large Container Research Articles

QUALIDADE E CRESCIMENTO INICIAL DE MUDAS DE <i>Mimosa caesalpiniifolia </i>Benth. PRODUZIDAS EM DIFERENTES VOLUMES DE RECIPIENTES

Geralmente, a qualidade de mudas florestais é aferida somente na fase de viveiro, ignorando-se o principal objetivo que é a resposta das mudas após plantio a campo. Objetivou-se avaliar a influência do volume do recipiente de produção na qualidade morfológica de mudas de Mimosa caesalpiniifolia Benth. no viveiro e na sobrevivência e crescimento inicial a campo. Foram testados cinco volumes de recipientes (30, 55, 110, 180 e 280 cm³), constituindo-se os tratamentos. Aos 90 e 120 dias após a semeadura, foram avaliadas as características altura (H), o diâmetro do coleto (DC), a matéria seca aérea (MSA), a matéria seca das raízes (MSR), o Índice de Robustez (H/DC), a matéria seca total (MST), a relação entre a matéria seca aérea e das raízes (RMSAR), a densidade de raízes (DR) e o Índice de Qualidade de Dickson. Após a última avaliação em viveiro, as mudas foram plantadas a campo. Aos 120 dias do plantio, foram avaliados a sobrevivência, a altura (H), o diâmetro ao nível do solo (DNS), e calculado o crescimento relativo (CR). Embora as mudas produzidas nos três recipientes de maior volume tenham apresentado maiores valores morfológicos de qualidade na fase de produção, constatou-se que após a implantação a campo esta diferença tende a desaparecer, sendo possível produzir mudas de qualidade de Mimosa caesalpiniifolia Benth., capazes de sobreviver, crescer e se desenvolver após o plantio, em qualquer um dos recipientes testados.

Energy-Saving Potential and an Economic Feasibility Analysis for an Arctic Route between Shanghai and Rotterdam: Case Study from China’s Largest Container Sea Freight Operator

Global warming has significantly reduced summer ice coverage in the Arctic region, providing long-awaited opportunities for the shipping industry to open new routes through a region known for its harsh navigational conditions. If a shortcut between Asia and Europe via the Northern Sea Route (NSR) is adopted, significant energy saving and pollution reduction are possible compared with conventional southern routes. However, opinions in literature differ regarding this shortcut’s economic viability. We present an analysis from the perspective of COSCO, China’s largest container sea freight operator. We perform a cost–benefit analysis under several scenarios considering the following current realities: (1) declining oil prices not seen for decades, even lower than the lowest prices assumed in previous studies; (2) declining Russian NSR tariff as an effort to attract shipping traffic; (3) possible emission control areas along a northern route may require much cleaner energy and thus impact costs not studied in previous models; and (4) the capital cost difference between a hired and a self-owned vessel. Classical case studies of shipping routes between Shanghai and Rotterdam are adopted for comparison. We explain how different factors impact the shipping costs and to what extent can the NSR be economically viable. Occasional usage of NSR (e.g., one time transit) is unlikely to be more profitable given the higher unit transportation cost, but the route could be economically competitive in terms of the total profits earned for continuous usage. A more aggressive scenario which requires ships on the NSR to switch to much cleaner fuel would erode this route’s competitiveness, but extra environmental benefits should be taken into consideration if future carbon emission trading schemes include the shipping industry.

Behavior of Ricinus communis L. plants due to different volumes of containers and substrates

Abstract: The objective of this study was to evaluate the production of castor bean seedlings due to different volumes of containers and substrates. The work was conducted from May to June 2014, in the nursery of the State University of Paraiba, Campus IV, Catole do Rocha, PB. The experimental design was a completely randomized design, adopting the 4 x 2 factorial scheme, with 6 replicates, with four container volumes: (polyethylene plastic bags with capacity 1000 dm³; polyethylene plastic bags with a capacity of 500 dm³; tubes with a capacity of 300 dm³ and disposable cups with a capacity of 270 dm³) and two types of substrates (S1 = 50% soil + 50% earthworm humus and S2 = 40% soil + 30% earthworm humus + 30% sand). The variables studied were: (LN) leaf number; (ULA) unitary leaf area; (RD) root diameter; (RL) root length; (SB) shoot biomass; (TPB) total plant biomass. All variables had a significant effect on cantainer volumes. Probably the largest container provided larger area of substrate to be explored. Castor bean seedlings of the BRS Gabriela variety respond well to larger container volumes. The substrate V1 (50% soil and 50% humus) influenced the initial growth of BRS Gabriela seedlings.

A numerical simulation method for predicting global and local hydroelastic response of a ship based on CFD and FEA coupling

In this paper, a simulation method for predicting global and local hydroelastic response of a ship which couples CFD and FEA is developed and validated. By comparing the prediction with linear/nonlinear strip method, 3D panel method and towing tank test results under various wave conditions in terms of rigid body motions and slamming impact pressure, the effectiveness of the CFD-FEA coupling method is confirmed. The hydroelastic behavior, so-called the whipping moment, evaluated from the CFD-FEA coupling method is further validated by comparing with nonlinear strip method, 3D panel method and tank test results. Finally, the proposed method is applied to a realistic large container ship structure in severe waves. The structural response of the double bottom structure subjected to global and local bending moments is investigated.

Reliability of Hull Girder Ultimate Strength of Steel Ships

Hull girder ultimate strength is an evaluation index reflecting the true safety margin or structural redundancy about container ships. Especially, after the hull girder fracture accident of the MOL COMFORT, the 8,000TEU class large container ship, on June 17 2013, larger container ship safety has been paid on much more attention. In this paper, different methods of calculating hull girder ultimate strength are firstly discussed and compared with. The bending ultimate strength can be analyzed by nonlinear finite element method (NFEM) and increment-iterative method, and also the shear ultimate strength can be analyzed by NFEM and simple equations. Then, the probability distribution of hull girder wave loads and still water loads of container ship are summarized. At last, the reliability of hull girder ultimate strength under bending moment and shear forces for three container ships is analyzed by using a first order method. The conclusions can be applied to give guidance for ship design and safety evaluation.

How do economies of density in container handling operations affect ships’ time and emissions in port? Evidence from Norwegian container terminals

Efficient port services are prerequisites for competitive and sustainable maritime transports. This paper makes advances in studying the determinants of the time that ships spend in port and the associated emissions to air. We estimate a production model for cargo handling based on a unique dataset containing each port of call at the largest container terminals in Norway in 2014. In turn, we use auxiliary engine emission factors to estimate particulate matter and nitrogen oxide emissions from ships at berth, to determine how the corresponding damage costs of air pollution vary with container throughput, location, and terminal investments. We find that Norwegian container terminals operate under increasing returns to density. Small ships that unload few containers are far from reaping economies of density, leading to high marginal time requirements for container handling and consequently high marginal external costs. From a Pigouvian taxation perspective, port charges should therefore be regressive in the number of containers handled. Moreover, we find that the external costs of maritime transports are severely understated when port operations are ignored. Our model allows determining the marginal productivities of port facilities. Thereby, it is instrumental in designing port charges that are diversified according to the quantity of containers handled and the service quality (i.e., the speed of handling operations). Regarding contextual factors, we find that establishing high-frequent liner services improves the ship working rate, while simultaneous calls at a terminal impede productivity. The type of container (loading/unloading; empty/laden) also appears to influence the duration of ship working.

Port mergers: Why not Los Angeles and Long Beach?

There have been significant attempts to merge the San Pedro Bay Ports of Los Angeles and Long Beach since their creation as separate municipal authorities in 1911. These efforts continue to the present day with the most recent proposal made in 2014. Yet all efforts to merge the two largest container ports in North America have failed. A review of attempts to promote or force the merger of the two ports was undertaken to identify the motivating factors behind the merger proposals, how the merger concepts were initiated and why they failed. Those who proposed merging the ports were typically business groups, port users or elected officials but not port administrators. Merger proposals were often motivated by the desire to eliminate what merger proponents viewed as destructive competition, duplication of facilities, or because one port coveted the resources of the other.Yet, all merger proposals have failed to gain widespread support for two primary reasons. First, all proposals came from outside the port administration, often generated without any port knowledge or participation and limited stakeholder involvement. Second, none of the merger proposals were accompanied by an objective analysis identifying the benefits to accrue to both port cities from a merger. Although attempts to merge the two ports failed, cooperative efforts between the ports increased in the 1980's, spurred by problems confronting both port administrations, that is, the impacts of containerization on the surrounding communities. The ports used a variety of governance tools to affect cooperative arrangements including creation of quasi-independent single purpose authorities. Initial efforts focused on improving hinterland infrastructure. The increased use of “discussion agreements” approved by the Federal Maritime Administration allowed the ports to expand cooperative efforts to environmental and logistics matters. The willingness and initiatives of the ports to cooperate, when necessary, has negated serious consideration of merger proposals. Instead, the two ports have increasingly expanded cooperative efforts to address common issues while retaining their independent jurisdictions.

Fully coupled time domain solution for hydroelastic analysis of a floating body

A numerical method is developed to study the ship hydroelasticity problem in time domain. Boundary – Element Method (BEM) with three-dimensional transient free-surface Green function and Neumann – Kelvin approximation is used for the solution of the hydrodynamic part. The structural domain is modeled by finite element method (FEM) using 1D beam element in time domain. The coupling between BEM and FEM is made through body boundary condition in the hydrodynamic solution. Furthermore, direct integration scheme, i.e. Newmark –β method is used for obtaining the structural velocity and deformation. The efficiency and robustness of the proposed method are validated with available published results. Three different barge type structures and a large container ship are taken for the analysis. A good correspondence is observed between the proposed and reported numerical and experimental results. Also, it is observed that structural flexibility plays an important role while calculating structural deflection, shear force, bending moment etc. The developed numerical method seems to be robust, efficient and a very useful tool in predicting the hydrodynamic loads, structural deflections, shears force, bending moment etc. for flexible structure.

High speed observation of fast crack propagation and arrest behaviour in 3D transparent structures

Crack arrester is employed for preventing brittle cracks from causing catastrophic failure of large steel structures. In large container ships, so called “structural crack arrest design” utilizing welded joint has been recently used to improve brittle crack arrestability of the structures. Although such design is already applied to commercial ships, the mechanism of crack arrest in such design has not been clear because crack behavior in the joint is 3D and hard to measure by conventional methods. Therefore, in order to clarify crack arrest mechanism in structural crack arrest design, 3D rapid crack propagation and arrest behavior was observed in T-joint-like structures made of transparent elastic material by using high speed camera. The observation showed that the crack front shape was significantly important to consider crack arrest mechanism because the semi-elliptical-like crack front shape in flange plates caused reduction of SIF and crack arrest.

UWB Radio Measurement and Time-Domain Analysis of Anisotropy in Wood Chips

Ultra-wideband (UWB) radio transmission measurements have been used to determine the moisture content of wood chips using a time-domain technique. Wood chips have been found to have birefringent dielectric properties acting as an anisotropic dielectric effective medium. Birefringence in wood chips occurs because of the orientation and the shape of wood chips and microscopic structures of these objects, such as wood fibers. The birefringence gives rise to two different wavefronts along the principal axes, which have different dielectric properties. Each wavefront has a specific time-domain signal that can be used to determine the moisture content. In industrial applications, for example, in measurement on wood chips in trucks, the vertical polarization direction is the preferable polarization because this signal has higher signal-to-noise ratio, which makes the signal more identifiable at longer distance (2–3 m). Thus, UWB radio transmission measurement and time-domain analysis is a robust technology to investigate larger containers of wood chips and to determine the moisture content with high accuracy.

A Basic Study on Brittle Crack Propagation Path with Ultra Large Steel Plate Weld Joints

As the recession in shipbuilding industry became longer, domestic shipbuilders focused on the need for high value added and high technology, and strived to build safer vessels. There are LNG carriers and container ships that require representative technologies. Both ship types are rapidly increasing ship size in the 2000s. Recently, there have been the increase of ship size and the development of oil and gas in arctic region. These trends have led to the requirements such as high strength, good toughness at low temperature and good weldability for prevent of brittle fracture at service temperature. Studies on unstable fracture have mainly been conducted to evaluate the brittle crack stopping properties of the high strength steel welded joints through large scale fracture tests, and studies on the difficulty of stopping brittle cracks in welded joints. It is known that BCA (Brittle Crack Arrest) steel has recently been developed to prevent unstable fracture if cracks propagate toward the BCA steel even if brittle cracks occur. Therefore, it is considered that the ship can be dried more easily if a technology capable of inducing the brittle crack to the BCA steel is developed. In this study, we describe a technique for securing unsafe fracture safety by inducing cracks toward the BCA steel, which has excellent brittle crack stopping ability, regardless of the welding process when brittle cracks occur in the superstructure of super large container ships. Key words: Brittl crak arrestability, Crack arrest toughness, Thick steel plate, FCAW, ESSO test, Welding residual stress

Crecimiento de plántulas de cacao (Theobroma cacao L.) en diferentes tamaños de contenedor

El volumen del contenedor para la propagación del cacao es determinante, ya que su tamaño influye en el crecimiento y desarrollo de las plántulas, siendo un factor definitivo para el establecimiento del cultivo. En este trabajo se comparó el efecto que tienen diferentes tamaños de contenedor 0,01; 0,02 y 0,1 m3 (volumen de sustrato) y la duración en vivero, sobre el crecimiento de plantas de cacao, además, se evaluaron los cambios en el sustrato confinado. Se sembraron semillas de cacao en contenedores de diferentes alturas: 25, 45 y 70 cm. Se midió la temperatura de las hojas y se colectaron plántulas, para cuantificar la biomasa particionada y crecimiento de la raíz principal. Simultáneamente fueron evaluadas la resistencia a la penetración, la temperatura, la humedad y la porosidad del sustrato. Los resultados evidenciaron diferencias significativas (P<0,05) en la acumulación de fitomasa total. En los contenedores de mayor tamaño (0,1m3) hubo mayor biomasa total, mayor longitud de raíces: 62,17 cm, el sustrato presentó menor resistencia a la penetración (0,52 Kg cm-2) y temperatura. La temperatura de las hojas se relacionó directamente con la temperatura del suelo e inversamente con la humedad del suelo. Se comprobó que el tamaño del contenedor afecta las características físicas del sustrato y el crecimiento de las plantas, lo cual sugiere que con 0,02 m3 (con 45 cm altura) del contenedor las plantas pueden permanecer 180 días en vivero.

Numerical investigation of three-dimensional hull girder ultimate strength envelope for an ultra large container ship

Ultra large container ship (ULCS) structures feature large deck openings and low torsional rigidity. It is essential to accurately evaluate the maximum loading carrying capacity of ship structures. When the ship sails at an oblique heading in rough sea, the horizontal and torsional moments may approach or even exceed the magnitude of vertical bending moment. In such cases, hull girder ultimate strength assessment of container ships under load combinations comprising of vertical bending moment, horizontal bending moment and torsion is necessary in their structural design stage. In this paper, special attentions are thus paid to the hull girder ultimate strength of an ULCS (i.e., a typical 10,000 TEU container ship) subjected to combined three load components mentioned above, which is also a common load case in ships and ship-shaped offshore structures and it is assumed that the three kinds of main loads can be combined each other freely. A series of nonlinear finite element analyses (NFEA) is carried out. Effects of fabrication related initial imperfections are investigated in the present study. Based on the computed numerical results, the 3D hull girder ultimate strength envelope considering initial deformation and incorporating the interaction relationships among three kinds of load components mentioned above is established.

Safe Mooring of Large Container Ships at Quay Walls Subject to Passing Ship Effects

Container traffic and individual ships’ sizes increased dramatically over the last decades, testing the existing harbour infrastructure to its limits. An important aspect regarding the safety of the berthed vessel is the quality of the mooring configuration. A case study is presented, where an 18000 TEU container vessel is moored at a quay. The motions of the moored vessel and the forces in its lines due to ship passages are simulated, using the potential software ROPES and the UGent in-house package Vlugmoor. Focus is on the mooring plan (operational parameter) and the characteristics of the individual lines (design parameter).

Numerical computation of motions and structural loads for large containership using 3D Rankine panel method

In this paper, we present the results of our numerical seakeeping analyses of a 6750-TEU containership, which were subjected to the benchmark test of the 2nd ITTC–ISSC Joint Workshop held in 2014. We performed the seakeeping analyses using three different methods based on a 3D Rankine panel method, including 1) a rigid-body solver, 2) a flexible-body solver using a beam model, and 3) a flexible-body solver using the eigenvectors of a 3D Finite Element Model (FEM). The flexible-body solvers adopt a fully coupled approach between the fluid and structure. We consider the nonlinear Froude–Krylov and restoring forces using a weakly nonlinear approach. In addition, we calculate the slamming loads on the bow flare and stern using a 2D generalized Wagner model. We compare the numerical and experimental results in terms of the linear response, the time series of the nonlinear response, and the longitudinal distribution of the sagging and hogging moments. The flexible-body solvers show good agreement with the experimental model with respect to both the linear and nonlinear results, including the high-frequency oscillations due to springing and whipping vibrations. The rigid-body solver gives similar results except for the springing and whipping.

Simulation of whipping response of a large container ship fitted with a linear generator on board in irregular head seas

There is plenty of energy contained in the ocean waves, and great efforts have been made over recent decades to make full use of these sustainable energy resources. As a novel device to utilize ocean wave energy, the authors propose in this paper a whipping energy converter, which utilizes a linear generator extracting power from ship’s whipping and springing (hull girder 2-node vibration) responses. The device is designed resonant to the hull girder 2-node vibration frequency. Numerical simulation of the responses of the whipping energy converter was carried out under irregular head sea condition, using time domain ship motion analysis by Rankine source method and subsequent three-dimensional whole ship FE analysis, and the main parameters of the whipping energy converter was studied. A 14,000 TEU large container ship was utilized in this study, because large container ship is prone to constant whipping and springing responses in real seas. As a result, it was found that the whipping energy converter can effectively generate power from the whipping and springing responses, and at the same time, the whipping energy converter functions as a dynamic damper. With the piston weight of 5–10 tons, the whipping vibration is visibly reduced, while if the piston weight is about 100 tons, the spectral peak is reduced to less than one-third. This implies that the whipping energy converter contributes to the prevention of fatigue damage due to whipping and springing, which is an imminent concern in the design of large container ships. It was also found that larger power generation can be expected as the piston weight is heavier, and the bow is the most effective location for this device.

Do container size and predator presence affect Culex (Diptera: Culicidae) oviposition preferences?

Organisms with complex life cycles typically do not exhibit parental care. Hence, the ability of adult females to choose quality oviposition sites is critical for offspring success. Gravid females of many insect taxa have the capability to detect environmental conditions in water-holding containers (e.g., resource level, presence of competitors or predators) and to choose the sites that are most suitable for offspring growth and development. Mosquitoes may also detect physical container characteristics related to water permanence such as surface area, volume, or container size, and some species such as those in the genus Culex have been shown to prefer larger containers. However, predators may also preferentially colonize larger containers; thus, ovipositing females may face decisions based on cues of site quality that balance the costs and benefits for offspring. We used a field experiment to evaluate the oviposition preferences of two Culex species in response to experimental container size and predator abundances within the containers. We found that both species avoided ovipositing in the largest containers, which have high abundances of Chaoborus sp. and dragonfly larvae (predators). However, the container size most commonly chosen for oviposition (15-L buckets) also had high mean abundance per liter of dragonfly larvae. These results suggest either prey naiveté or reduced vulnerability of these species to dragonflies compared to Chaoborus sp. Other potential mechanisms for the observed patterns are discussed.

A general heuristic for two-dimensional nesting problems with limited-size containers

Cutting raw-material into smaller parts is a fundamental phase of many production processes. These operations originate raw-material waste that can be minimised. These problems have a strong economic and ecological impact and their proper solving is essential to many sectors of the economy, such as the textile, footwear, automotive and shipbuilding industries, to mention only a few. Two-dimensional (2D) nesting problems, in particular, deal with the cutting of irregularly shaped pieces from a set of larger containers, so that either the waste is minimised or the value of the pieces actually cut from the containers is maximised. Despite the real-world practical relevance of these problems, very few approaches have been proposed capable of dealing with concrete characteristics that arise in practice. In this paper, we propose a new general heuristic (H4NP) for all 2D nesting problems with limited-size containers: the Placement problem, the Knapsack problem, the Cutting Stock problem, and the Bin Packing problem. Extensive computational experiments were run on a total of 1100 instances. H4NP obtained equal or better solutions for 73% of the instances for which there were previous results against which to compare, and new benchmarks are proposed.

Quasi-Static Response of a 19,000 TEU Class Ultra Large Container Ship with a Novel Mobile Deckhouse for Maximizing Cargo Capacity

Quasi-Static Response of a 19,000 TEU Class Ultra Large Container Ship with a Novel Mobile Deckhouse for Maximizing Cargo Capacity

Study on the course stability of very large vessels in shallow water using CFD

When the large vessels, such as very large container ships and conventional VLCCs, are navigated in shallow water, it is necessary to accurately estimate the course stability as well as the squat of the ship to ensure safety. The purpose of this study is to analyze the course stability characteristics by vessel type, which can evaluate the navigation safety of very large vessels navigating at low speed in shallow water. Numerical simulations were carried out using CFD for KVLCC2 and DTC with respect to depth of water, drift angle, and angular velocity. The maneuvering performance in shallow water were analyzed by estimating the hydrodynamic derivative from the results of the numerical calculations. As the drift angle and angular velocity increased, the magnitudes of sway force and yaw moment became larger. The hydrodynamic derivatives at H/T = 1.2 were very large compared with that at other depths. The course stability at H/T = 1.2 was significant regardless of the type of vessel, and found to be more significant in KVLCC2 compared to DTC. The nonlinear effects such as vortex flow and pressure distribution on the hull were also analyzed through a flow field analysis around the hull.