Large Container Research Articles

A study on whipping related double bottom response as well as its statistical characteristics based on full-scale measurements

Recently, the great enlargement of container ships has brought broad concern on the effect of whipping response. Meanwhile, the accompanying wider width of double bottom may cause more flexible responses of the double bottom structures. The numerical simulation studies have shown that the longitudinal stresses of the hold central bottom of a container ship due to the double bottom bending superimpose on the longitudinal stresses due to hull girder bending in both wave response component and vibrational response component. In this research, the authors firstly extract the full scale measurements data whose sea states are closest to that of numerical simulation among existing time series, with the purpose of analyzing correlation between double bottom bending and hull girder bending in wave response and vibrational response. As a result, studies from full scale measurements well verified the phenomenon that double bottom of larger container ship responds to forced vibration due to whipping excitation as observed in theoretical studies. Then, the statistical characteristics of correlation factor between hull girder bending stress and double bottom bending stress were investigated, based on relatively large number of data with regard to wave height and relative wave direction, as well as the classification between low- and high-frequency-dominant response cases. All these studies may contribute to future optimized operation, maintenance and design of ship.

Prediction of Fatigue Strength of Extra-Large Container Ships Based on Spectrum Analysis

Wang, J.T.; Jiang, B.C., and Guo, Y.L., 2020. Prediction of fatigue strength of extra-large container ships based on spectrum analysis. In: Al-Tarawneh, O. and Megahed, A. (eds.), Recent Developments of Port, Marine, and Ocean Engineering. Journal of Coastal Research, Special Issue No. 110, pp. 146–149. Coconut Creek (Florida), ISSN 0749-0208.With the rapid development of maritime transportation industry, container ships have quickly become the mainstream ship model due to their advantages of fast shipping speed, high handling efficiency, and low operating costs. At the same time, their large-opening structure has resulted in poor performance in bending strength, torsional strength and other mechanical properties. In order to ensure the structural safety performance of extra-large container ships, it is necessary to conduct an in-depth research on its fatigue damage and strength life. Based on the spectrum analysis, this paper takes the model 8601ETP extra-large container ship as an example, and adopts finite element modeling to obtain distribution range of the alternating stress; it also uses SN curve and linear cumulative damage theory to predict the fatigue damage and strength life of the container ship. The research results show that the fatigue damage of the extra-large container ship at full load is significantly more severe than that at no load; the degree of structural damage at the position of the keyhole is greater than that at the position of the hatch corner, so it is the hotspot for the fatigue damage analysis and strength check of extra-large container ships. This study provides certain theoretical reference and data support for improving the safety performance of large container ships, and it also enriches the theory of fatigue strength evaluation.

Controlling the parametric roll of a container ship model by changing the forward velocity

Parametric roll on ships is a resonance phenomenon whose onset causes heavy roll oscillations leading to dangerous situations for the ship, the cargo and the crew. It affects both small vessels with marginal stability and large container ships if four conditions are met simultaneously: the wave length and ship length are approximately equal, the frequency of encounter wave is twice the roll natural frequency, the ship’s roll damping is low enough and the wave height exceeds a limit value characteristic to each vessel. A good start to capture the basic features of the parametric roll is to cancel the couplings between roll and the other motions of the ship and to analyse the influence of parameters on the ship stability and the appearance of large roll amplitudes by using one-degree-of-freedom model. By doing this, one realizes that, besides increasing the damping, the roll motion can be stabilized by changing the wave encounter frequency in such a way that the resonance condition is no longer fulfilled. Two parameters mainly affect the encounter frequency: the ship forward velocity and the heading angle. In the paper, we have numerically investigated the effect of increasing or decreasing the forward speed on the roll amplitudes. We followed two strategies. In the first, we allowed the speed to change with a constant acceleration (positive or negative) so that the encounter frequency has left the dangerous region of the resonance. In the second strategy, we changed the forward speed up and down around a value that generates large roll amplitudes, by using different periodic profiles such as sinusoidal, saw tooth or trapezoidal. We noticed that both control techniques generally managed to significantly reduce the roll amplitudes (with a few exceptions). At the same time, we found that very important in how the amplitudes diminish are parameters like the moment of time when the control is activated, the speed rate of change or the period and amplitude of the speed change around the average value (in the second strategy). The data used in the paper have been obtained from experiments with a container ship model in a towing tank followed by expansion to a full scale ship.

Salinity Intrusion in a Modified River-Estuary System: An Integrated Modeling Framework for Source-to-Sea Management

Along the US Atlantic and Gulf coasts, port authorities and governments have been competing for access to federal funds to deepen the channels and berths in each of the major estuary-based harbors, thereby facilitating access by larger containerships. Consistent with a source-to-sea conceptualization, physical modifications of an estuary can result in dynamic changes to its water and sediment flows, resulting in new arrangements of environmental features. These modifications, in turn, can lead to redistributions of the net benefits arising from extant flows of valued ecosystem services to stakeholders and communities in the broader river-estuary system. Here, some of the implications of channel deepening in the Hudson river-estuary system were examined as a case study. An integrated analytical framework was developed, comprising hydrodynamic models of water flows and environmental characteristics, especially salinity; extreme value estimates of the occurrence of regional droughts; and assessments of the welfare effects of changes in ecosystem services. Connections were found among channel deepening in the lower estuary, increased risks to fluvial drinking water withdrawals in the upper estuary, and expected economic losses to hydropower generation in the upper river. The results argue for a more inclusive consideration of the consequences of human modifications of river-estuary systems.

Vessel noise in spatially constricted areas: Modeling acoustic footprints of large vessels in the Cabot Strait, Eastern Canada

Large commercial vessel traffic is expected to continue growing over the next decades, making marine habitats noisier. This additional vessel noise could prevent the recovery of endangered marine species and populations and become a threat to others. Spatially constricted areas are places where both maritime traffic and species can concentrate, increasing the risks of negative impacts. We assessed sound amplitude and temporal trends in the daily movement of large ferries, container ships, bulkers, and tankers in the Cabot Strait, the main entrance way to the Gulf of St. Lawrence Seaway in Atlantic Canada. We used Automatic Identification System (AIS) and geophysical data as input for an acoustic model to produce 12 scenarios representing different regimes of vessel traffic and estimated equivalent continuous noise levels (Leq) over a 24-h period. Our results show that a 50% increase from the estimated median number of large vessel transits could lead to a 23% increase in the area affected by vessel noise, while doubling the number of transits could lead to a 58% increase. Cetaceans located <7–8 km from a vessel could experience sound pressure levels above the U.S. 120 dB re 1 μPa threshold for the onset of behavioral disturbance. Introducing speed restrictions could help reduce the acoustic footprint of the four vessel classes in this area and limit possible negative effects on marine mammals and other marine species.

Ultimate strength envelope of a 10,000TEU large container ship subjected to combined loads: From compartment model to global hull girder

The main objective of this research is to figure out the relationship of the ultimate strength characteristics between the compartment hull girder and the global hull girder, especially focusing on the ultimate strength envelope of the global hull girder of a 10,000TEU ultra large container ship subjected to combined loads, which is one of the most important indexes to quantify the safety margin of the container ship. To achieve these aims, both the compartment hull girder and the global hull girder are modeled based on true ship hull girder's configurations. A series of full-scale nonlinear finite element analyses are performed. In addition, to examine the reliability of the elastic-perfectly plastic material models employed in FEA, similar scale model collapse experiments of a compartment hull girder subjected to pure hogging and pure torsion are also presented. Finally, the ultimate strength envelope of the global hull girder of the 10,000TEU ultra large container ship subjected to combined vertical bending and torsion is quantitatively obtained, which can characterize the container ship hull girder's ultimate strength interactions between vertical bending and torsion and quantify the safety margin of the global hull girder of the container ship subjected to combined vertical bending and torsion.

Dynamic pricing research for container terminal handling charge

ABSTRACT The purpose of this study is to provide a new pricing strategy for the container terminal handling charge (THC) of terminals. A dynamic pricing model is established by using the Back Propagation Neural Network (BPNN) algorithm and the Time-Driven Activity-Based Costing method. This pricing strategy can dynamically amend the price of the container THC based on handling demand, recent charge standards per container, and handling time for a particular customer. To some extent, this dynamic pricing strategy can provide a valuable reference for terminals in pricing decisions. This case study implemented the dynamic pricing model at the Shanghai ShengDong International Container Terminal, one of the largest container terminals in China. The results show that this pricing model dynamically adjusts the container THC depending on customers’ handling conditions. Besides, this dynamic pricing model is more precise than the traditional contractual pricing used at the terminal. Compared with the BPNN algorithm, the optimized BPNN algorithm has faster convergence speed and less learning error. Moreover, this pricing method is universally applicable to the container THC pricing problem of most terminals.

An investigation into container constraint effects on the cavity characteristics due to high-speed projectile water entry

In this paper, the influence of container dimension constraints on the cavity expansion characteristics were preliminary investigated through series of high-speed water-entry experiments with velocity in the range of 80–470 m/s. Particular attention is given to the characteristics of cavity evolution, surface and deep closure, average cavity wall velocity and the drag coefficient under container constraints. In the test configurations, three size cylindrical-shaped containers were employed, a digital high-speed camera system is used to photograph the projectile motion and cavity expansion within the water-filled containers. Experimental results show that the cavity in a larger container will reach a larger radius and collapses later than the cavity in a much smaller container. The container size has little effect on the time of surface closure and the location of deep closure but more on the time of deep closure. Moreover, it is found that as the container size decreases to a magnitude of the cavity diameter, the projectile velocity attenuation will be strongly affected by the container constraint. The objective of the present study is to provide original dynamic data for studying the nature of hydrodynamic ram caused by the cavity expansion in subsequent work.

Strategi Peningkatan Kinerja Operasional Bongkar Muat Peti Kemas: Studi Kasus di PT Jakarta International Container Terminal

PT JICT is largest container terminals at Tanjung Priok and has capacity of container up to four million TEUs(Tweenty Foot Equivalent). To compete with other container terminal at Tanjung Priok, JICT needs to evaluate and determine strategy for improving operational performance. The purposes of this research is to indetify internal factor and external factor that influence operational performance at PT JICT and to determine priority of alternative strategy to improve operation container terminal performance.This study used 4 analysis tools matrix i.e. IFE (Internal Factor Evaluation) and EFE (External Factor Evaluation), BSC (Balanced Scorecard), AHP (Analytical Hierarchy Process), and Analytical Network Process ( ANP). The result showed that position JICT in quadran I with weigh (3.79; 3.16) indicated that JICT phase in grow and build. The results of BSC and AHP showed that perspective of the customer is the first priority that influence operational performance improvement with a weight of 0.48. The main priority alternative strategies generated by using the ANP method to improve operational performance are maintenance of operational facilities and equipment on a regular schedule as well as investing in new operational equipment with a weight of 0.0321. Keywords: AHP, ANP, BSC, Operation of loading unloading container

Port-Related Emissions, Environmental Impacts and Their Implication on Green Traffic Policy in Shanghai

The port of Shanghai, as the world’s largest container port, has been experiencing rapid development in recent years, with increasing cargo throughput capacity. The combustion of diesel fuels used by internal and external port-related container trucks and in-port machineries can release various pollutants, causing air pollution. The terminals are close to the residential area, and the emissions are concentrated, which is worth paying attention to. This study aims to synthetically assess the port-related emissions and their environmental impacts. We firstly constructed an emission inventory of air pollutants in the port of Shanghai and then used the WRF-CMAQ model to estimate the influence of port-related source emissions on air quality. The results show that the annual emissions of SO2, NOX, CO, VOCS, PM, PM10, PM2.5, CO2, BC and OC caused by cargo-handling equipment were 21.88 t, 1811.22 t, 1741.72 t, 222.76 t, 61.52 t, 61.42 t, 58.41 t, 141,805.40 t, 26.80 t and 10.07 t in 2015. The emissions of NOX, CO, VOCS, PM10 and PM2.5 caused by external port-related container trucks were 18,002.92 t, 5308.0 t, 1134.57 t, 711.12 t and 640.58 t. The exhaust of external port-related container trucks was much larger than that of cargo-handling equipment, so the impact on air quality was also higher than that of the machinery. The peak annual average concentrations of PM2.5 and NOX contributed by the port-related sources were 1.75 μg/m3 and 49.21 μg/m3, respectively, which accounted for 3.08% and 36.7%, respectively, of the simulated ambient concentrations by all the anthropogenic emissions in Shanghai. Our results imply that the emission control policy to reduce the combined port-related emissions, especially for the cargo-delivery transportation phase from port to city, is key for large coastal port cities such as Shanghai.

Fatigue Assessment of Very Large Container Ships Considering Springing Effect Based on Stochastic Approach

Fatigue Assessment of Very Large Container Ships Considering Springing Effect Based on Stochastic Approach

Statistical Analysis of Vertical and Torsional Whipping Response Based on Full-Scale Measurement of a Large Container Ship

In this study, as a preliminary attempt to reveal the whipping response of large container ships in actual seaways, the stress monitoring data of an 8600 TEU large container ship were analyzed. The measurement lasted approximately five years, and using a large amount of data, we investigated how the sea state and operational conditions affected the whipping response. In addition, the midship longitudinal stresses were decomposed into hull girder vertical bending, horizontal bending, and torsional and axial components. Thereafter, we found that the whipping magnitude on the torsional and horizontal bending components is much smaller than that on the vertical bending component. Future research would include the analysis of a larger amount of data, analysis of other sensor data, and effects of various patterns of vibrational response on the ultimate strength and fatigue strength. The obtained results will benefit the future design and operation of large container ships for safer navigation.

Aerosol tracking using lidar-based atmospheric profiling and Bayesian estimation

Soot aerosol in atmosphere is one of deadliest forms of air pollution and is a major cause for health problems according to EPA. Compact light detection and ranging (lidar) systems can be used to obtain aerosol profile measurements by identifying aerosol scattering ratios as function of altitude. Aerosol ratio parameters are known to vary with aerosol type, size, and shape. This work employs a ground-based lidar system to detect the source of soot emissions in atmosphere in a wide area around the campus of Old Dominion University (ODU), Norfolk, VA. Different aerosol scattering ratio parameters including lidar and color ratios are obtained from collected lidar data around the campus and these ratios are analyzed for detection and quantification of soot aerosol. A Bayesian estimation algorithm was chosen, after extensive study, to determine the source of the soot in the measurements by tracking the pollution concentration. Results of the analysis using lidar data show that the source of soot pollution is a nearby major Hampton Blvd. Hampton Blvd. is a major arterial with traffic signals through the ODU campus where diesel trucks frequently travel to serve Port of Virginia, which ranks as the third largest container port on the East Coast.

Reliability analysis of hull girder ultimate strength for large container ships under whipping loads

The two incident reports for MSC (Mediterranean Shipping Company) Napoli in 2008 and MOL (Mitsui O.S.K. Lines) Comfort in 2015 both pointed out that whipping response was one main reason for inducing the catastrophes. Subsequently, International Association of Classification Societies (IACS) proposed a Unified Requirement (UR) S11A for ultimate strength evaluation of container ships, and main classification societies also updated their guidelines for whipping response. However, there are big differences in these requirements, and the safety level of ultimate strength under whipping loads is still unclear. This article is to find the effect of the whipping loads on hull girder reliability. Two large container ships 14500TEU and 19000TEU designed by China Classification Society (CCS) Rules are selected as case studies. Hull girder ultimate capacity in mid-ship section under hogging conditions is adopted as the dangerous failure mode, which is predicted by the increment-iterative method in IACS Common Structural Rules (CSR). The whipping effect on hull girder reliability is accounted for by a factor attaching on wave-induced moment. Then, a new evaluation criterion is proposed to evaluate hull girder ultimate strength for container ships under whipping loads, and sensitivity analysis of whipping effect is carried out. The conclusions in this article can provide a guidance for revising rule requirements in classification societies and optimising container ship structural design.

Container Type Affects Mosquito (Diptera: Culicidae) Oviposition Choice.

Larvae of container-breeding mosquitoes develop in a wide range of container habitats found in residential neighborhoods. Different mosquito species may exhibit preference for different container types and sizes. Due to phenological differences, species composition in container habitats may change over time. We first conducted weekly neighborhood container surveys to determine the types of container habitats found in residential neighborhoods, and to determine mosquito species composition over time within these habitats. We then conducted an oviposition choice field assay to determine whether female mosquitoes of different species preferentially oviposit in different container types commonly found in neighborhoods. Halfway through the experiment, the largest container was removed at half the sites to test the hypothesis that incomplete source reduction alters oviposition preference among the remaining containers. In the neighborhood surveys, large containers had the greatest mosquito densities and the highest species richness. Aedes albopictus (Skuse), the most commonly collected mosquito, was found in all container types. The oviposition experiment indicated that Culex spp. females preferentially oviposit in large containers. When the largest container was removed, the total number of egg rafts decreased. Aedes spp. females preferred to oviposit in large- and medium-sized containers, but the total number of eggs laid did not change when the large container was removed. These results confirm that understanding habitat preferences of container-breeding mosquitoes is important to control efforts targeting vector species and that incomplete removal of container habitats may have unpredictable consequences for the distribution of juveniles among remaining habitats.

Outplanting performance of three provenances of Quillaja saponaria Mol. established in a Mediterranean drought-prone site and grown in different container size

In degraded environments with restricted seed availability, like those burned by wildfires in central Chile during 2017, the use of plant material from outside its area of origin for restoration purposes needs to be accurately investigated. We assessed the early development of three Chilean provenances of Quillaja saponaria grown in different container sizes (140 vs. 280 mL) in the nursery and then outplanted in a common field trial at a site severely affected by fire under Mediterranean-type climate. We analyzed growth, biomass, and leaf-level physiological traits. In the nursery, there was a significant provenance by container type interaction for the biomass traits (P < 0.05). Seedlings from the Maule provenance cultivated in larger containers had the highest biomass, while the lowest biomass was observed for the Metropolitan provenance cultivated in small containers. Two years after outplanting, the provenance by container size interaction was significant for stomatal conductance and chlorophyll density. Seedlings from the Metropolitan provenance cultivated in larger containers exhibited a higher stomatal conductance, while those from the Maule provenance cultivated in small containers exhibited the highest chlorophyll density. Seedling height showed significant variation for provenance and container size. The tallest seedlings were those grown in larger containers from the Maule provenance; however, no differences in survival and height increment were found. Gas exchange parameters differed among provenances, the Metropolitan provenance had a low performance and the opposite was found for the Biobío and Maule provenances. This study demonstrated that different provenances of Q. saponaria have stable performances in a Mediterranean site, which support their use for restoration purposes outside their home area with no detrimental effects on outplanting performance.

Techniques for seedling production of two native grasses: new perspectives for Brazilian Cerrado restoration

There is a major need for restoration of nonforest ecosystems in the Brazilian Cerrado, and planting seedlings is promising. However, there is no currently available information on nontree species production in nurseries. Grasses are dominant in the Cerrado herbaceous layer; therefore, we tested whether tree seedling production techniques can be used for two native grasses widely spread across the Cerrado ecoregion (Schizachyrium sanguineum and Loudetiopsis chrysothrix). We performed a factorial experiment with three levels: (1) seedbed substrate, (2) container volume, and (3) final substrate. Seeds were germinated in seedbeds with native soil or sand and, after emergence, transferred to 30, 55, or 290 cm3 containers filled with native soil, commercial substrate, or a mixture thereof. We evaluated seedling survival, height relative growth rate (RGR), tillering, and dry biomass. Survival rates after transfer from seedbeds to containers were greater than 80% for both species. Generally, species had greater height RGR, tillering, and biomass in the 290 cm3 containers than in the other containers, and the presence of native soil in the seedbeds, as well as in the containers, fostered seedling growth. However, the use of native soil is not recommended for large‐scale production, because its acquisition could degrade Cerrado areas. The commercial substrate improvement could be an alternative to increase seedling growth, since grasses survived well and presented greater growth in the largest container. Our study demonstrated that the techniques currently used in commercial nurseries for growing trees are suitable for both grasses, and substrates and container size drive seedling growth.

Dimensional precision controlling on out-of-plane welding distortion of major structures in fabrication of ultra large container ship with 20000TEU

Ultra large container ship as an essential role during international trade, is required for precision fabrication due to highly efficient TEU loading and unloading. In this study, two major structures, so called watertight transverse bulkhead structure and torsion box structure of ultra large container with 20000TEU were examined for out-of-plane welding distortion prediction and mitigation with measurement and computational analysis. Based on the welding inherent deformation theory, typical welded joints of two major structures were systematically classified with the different material, thickness, welding condition and joining form; and the relationships between welding heat input and inherent deformations were also presented. Elastic FE analysis with shell elements model and welding inherent deformation as input loading was employed for welding distortion prediction. Not only the distributions but also the magnitudes of predicted out-of-plane welding distortions of considered major structures have a good agreement comparing to the measurements. Furthermore, welding sequence influence was considered for dimensional precision controlling during the watertight transverse bulkhead structure fabrication, and welding groove optimization of thick plate was examined for out-of-plane welding distortion mitigation during the torsion box structure fabrication. Computational results show that welding distortions of both ship block structures can be significantly reduced for requirement of fabrication precision.

A study on prediction of whipping effect of very large container ship considering multiple sea states

In the design stage of the very large container ships, some methodologies for the whipping effects have been developed, but most of them are based on single sea state. We developed a methodology that considers multiple sea states. Fluid-structure Interaction (FSI) analyses with one dimensional structural model were carried out to capture slamming-induced transient whipping behaviors. Because of the nature of random phases of the applied wave spectra, the required period for entire FSI analyses was determined from the convergence study where the whipping effect became stable. Low pass filtering was applied to the transient whipping responses to obtain the hull girder bending moment processes. Peak counting method for the filtered whipping responses was used to obtain collection of the vertical bending moment peaks. The whipping effect from this new method is compared with that from based on single sea state approach. The efficiency and advantage of the new methodology are presented.

Saronikos Gulf: a hotspot area for alien species in the Mediterranean Sea

Shipping is the greatest pathway of non-indigenous species (NIS) introductions, and port areas are considered as alien hotspots. In this study, we analyzed data covering a 112-year period and found that Saronikos Gulf in Greece, hosting one of the largest container port terminals in Europe, is a hotspot of NIS introductions. To date, 89 NIS have been recorded, of which 8 are characterized as invasive. Most species belong to the taxonomic group of Mollusca (33%), followed by Pisces (22%). For the first time in the Mediterranean Sea, we report the presence of the micromolluscs Sinezona plicata (Hedley, 1899) and Ringicula sp. Moreover, we provide evidence for the trend of NIS introduction in the Saronikos Gulf across the past 70 years, the pathways of introduction and their importance through time, as well as the distribution of the most invasive species in the Saronikos Gulf. The information provided herein can assist the implementation of the EU Marine Strategy Framework Directive and inform NIS management. As Transport-Stowaway remains the main pathway of NIS introduction in the Saronikos Gulf, our principal recommendation is to reinforce regulations for the adoption of better antifouling practices and more effective ballast water treatment and management.