Journal articles: 'Pontoons'

1

Blazich, Frank A. "Inventors and Innovators: Naval Lighterage and Anglo-American Success in the Amphibious Invasions of German-Occupied Europe." Northern Mariner / Le marin du nord 31, no. 2 (November 2, 2021): 125–72. http://dx.doi.org/10.25071/2561-5467.155.

Full text

Abstract:

The amphibious invasions of Sicily, Salerno, and Normandy all made ample use of US Navy landing pontoons. The simple steel box pontoons were the brainchild of civil engineer Captain John N. Laycock, who developed and perfected his inventive design on the eve of American entry into World War II. Once in the conflict, a Royal Navy reserve officer assigned to Combined Operations Headquarters, Captain Thomas A. Hussey, conceptualized innovative uses for the American pontoons for offensive amphibious operations. Working together, these men developed pontoon causeways and massive lighterage barges which ensured logistical success in the invasions of German-occupied Europe. Les invasions amphibies de la Sicile, de Salerne et de la Normandie ont toutes fait appel aux pontons de débarquement de la Marine américaine. Les simples pontons flottants en acier ont été créés par le capitaine John N. Laycock, ingénieur civil, qui a développé et perfectionné sa conception géniale à la veille de l’entrée des États-Unis dans la Seconde Guerre mondiale. Une fois le conflit déclenché, le capitaine Thomas A. Hussey, officier de réserve de la Marine royale affecté au quartier général des opérations combinées, a mis au point des utilisations novatrices des pontons américains pour les opérations amphibies offensives. La collaboration de ces deux hommes a permis de développer des chaussées de pontons et d’énormes barges de chalandage qui ont assuré le succès logistique des invasions de l’Europe occupée par les Allemands.

APA, Harvard, Vancouver, ISO, and other styles

2

Freeman, Elizabeth L., Kristen D. Splinter, Ron J. Cox, and Francois Flocard. "Dynamic Motions of Piled Floating Pontoons Due to Boat Wake and Their Impact on Postural Stability and Safety." Journal of Marine Science and Engineering 10, no. 11 (November 2, 2022): 1633. http://dx.doi.org/10.3390/jmse10111633.

Full text

Abstract:

Piled floating pontoons are public access structures that provide a link between land and sea. Despite floating pontoons being frequented by the public, there is limited data available to coastal or maritime engineers detailing the dynamic motions (acceleration and rotation) of these structures under wave action and the impact of these motions on public comfort and safety to inform their design. This contribution summarises results from a set of laboratory-scale physical model experiments of two varying beam width piled floating pontoons subjected to boat wake conditions. Observed accelerations and roll angles were dependent on beam-to-wavelength ratio (B/L), with the most adverse motion response observed for B/L ~0.5. Internal mass of the pontoon played a secondary role, with larger mass structures experiencing lower accelerations for similar B/L ratios. Importantly, these new experimental results reveal the complex interaction between the piles and pontoon that result in peak accelerations more than six times the nominated operational safe motion limit of 0.1g. Root mean square (RMS) accelerations were more than three times the nominated comfort limit (0.02g) and angles of rotation more than double what would be perceived as safe (6 degrees) for the boat wake conditions tested. The frequency of acceleration also suggests patrons standing on these platforms are likely to experience discomfort and instability. Laboratory results are compared against a series of field-scale experiments of pontoon motion response and patron feedback. The dynamic motion response of pontoons tested in both field-scale and laboratory experiments compared well.

APA, Harvard, Vancouver, ISO, and other styles

3

Rajabi, Meysam, Hassan Ghassemi, and Hamidreza Ghafari. "Homogeneous Wave Load Effects on the Connections of Main Parts of Side-Anchored Straight Floating Bridge." Mathematical Problems in Engineering 2021 (July 13, 2021): 1–15. http://dx.doi.org/10.1155/2021/2855051.

Full text

Abstract:

In this paper, a numerical study is presented to investigate wave force on the connections of main parts of a side-anchored straight floating bridge concept for the Bjørnafjorden fjord crossing. The floating bridge is supported by 18 pontoons, and three groups of mooring lines are employed to restrain the bridge against horizontal loads and increase its transverse stiffness. The created wave forces at the connections of pontoon-column and column-girder of the floating bridge considering the effects of short-crested and long-crested waves, varying wave direction, hydrodynamic interaction between pontoons, and mooring system are analyzed. It is found that short-crested and long-crested waves depending on their direction decrease or increase the wave forces on the joints. Considering that the effect of hydrodynamic interaction between pontoons can increase or reduce the wave forces and moments created in the joints, which means the neglect of the hydrodynamic interaction effects between the pontoons to simplify the modeling of this type of floating bridge, may be unacceptable. Moreover, the results showed that the bridge mooring system does not merely reduce the wave forces and moments at joints along the bridge.

APA, Harvard, Vancouver, ISO, and other styles

4

Windyandari, Aulia, and Ahmad Fauzan Zakki. "RANCANG BANGUN MODULAR FLOATING PONTOON FERROCEMENT SEBAGAI ALAT APUNG MULTIGUNA." ROTASI 16, no. 4 (October 1, 2014): 1. http://dx.doi.org/10.14710/rotasi.16.4.1-8.

Full text

Abstract:

Modular floating pontoon is a floating device commonly used as civil and marine construction. Pontoon is usually made of steel and high-density polyethylene (HDPE). Although the steel and HDPE has its own advantages and disadvantages in terms of economic, strength, and capacity. However the study of alternative raw materials for modular floating pontoon construction as multipurpose floating equipment is needed. Ferrocement which is familiar in the used for building construction material is an alternative material. Since the material is easy to find and it is such a versatile material that can be mass produced and has the mechanical strength that is simillar to steel and other materials. Following that condition the research is focused on the application of ferrocement technology for modular floating floating pontoon. The results show that the principal dimension of modular floating pontoon are length 80 cm, width 80 cm, height 75 cm, with the lightweight draft of pontoons is 30 cm. The material proportions for the modular floating pontoon are sand 48.2%, cement 34.5% and water 17.3%. Modular floating pontoon series consists of four Pontoons Square compiled with interlink (hook) so that the total of the package pontoon has a 160 cm long, 160 cm wide and 75 cm high.

APA, Harvard, Vancouver, ISO, and other styles

5

Li, Hao, Junhua Chen, Lingjie Bao, and Chuhua Jiang. "Research on Wave Attenuation Performance of Floating Breakwater." Energies 14, no. 24 (December 10, 2021): 8316. http://dx.doi.org/10.3390/en14248316.

Full text

Abstract:

In this study, a new type of double-pontoon floating breakwater was designed to improve the wave attenuation performance through the addition of suspended Savonius propeller-blade. Its hydrodynamic characteristics were studied through numerical simulations and performance-testing experiment. The following investigations were performed in this study: Firstly, wave theory and hydrodynamic theory were combined to calculate the wave attenuation performance and motion response of double-pontoon floating breakwater under linear wave conditions. The numerical results showed that the wave attenuation performance was better under a specific wave period and height, the transmission coefficient reached a relatively small value, and the mooring line tension responded periodically and satisfied the condition of maximum breaking force. Secondly, three key geometric parameters of breakwater were researched, including the relative spacing of pontoons, the relative spacing between pontoons and blades, and the height–diameter ratio of Savonius blades. The calculation results showed that the pontoon spacing was closer to the wavelength and the breakwater wave attenuation performance was better. Lastly, experimental tests were also performed on the new double-pontoon floating breakwater and the results showed that the wave attenuation performance and numerical projections were basically the same, which verified the validity and effectiveness of the design method.

APA, Harvard, Vancouver, ISO, and other styles

6

Igwe, Icho Seimokomoh, and Tolumoye John Ajoko. "Analysis and Design of Steel a Floating Pontoon Jetty for Use in the Coastal Waters of Nigeria." European Journal of Engineering Research and Science 5, no. 9 (September 4, 2020): 1013–21. http://dx.doi.org/10.24018/ejers.2020.5.9.1863.

Full text

Abstract:

Floating pontoons are semi-permanently moored structures on a water body to provide boarding access to commuters. The decision to develop such structures was informed by the need to provide berthing access to river crafts that operate on the coastal waters of Bayelsa State, Nigeria. In this project, a floating pontoon, a gangway, and other supporting structures like scantlings and spud pillars, were designed to meet the needs and environmental requirements of the area. Standards consulted are the DNV Rules for the classification of ships; DNV Rules for the classification of Floating Docks; ABS Rules for Building and Classing Steel Barges; and other relevant Nigeria and Imo standards. The pontoon designed has dimensions: 13 x 12 x 4.8 m; gross tonnage of 15 tonnes; 2nos. of dry tanks of capacity 17.2 m³ and 6nos. of manholes of 450 x 550 mm. The strength of materials analysis was limited to the floating pontoon for limitations of space for this paper. The pontoon and scantling design has been done based on the worst condition of design pressure which is for the maximum submersion draft. Normal grade steel of yield strength 235 MPa is chosen for all members except the pontoon girders, frames and pillars. This is to reduce the material scantlings and to ensure higher strength with lesser scantlings. Longitudinal framing is adopted in the pontoons as the pontoon structure needs more strength in the longitudinal direction.

APA, Harvard, Vancouver, ISO, and other styles

7

Igwe, Icho Seimokomoh, and Tolumoye John Ajoko. "Analysis and Design of Steel a Floating Pontoon Jetty for Use in the Coastal Waters of Nigeria." European Journal of Engineering and Technology Research 5, no. 9 (September 4, 2020): 1013–21. http://dx.doi.org/10.24018/ejeng.2020.5.9.1863.

Full text

Abstract:

Floating pontoons are semi-permanently moored structures on a water body to provide boarding access to commuters. The decision to develop such structures was informed by the need to provide berthing access to river crafts that operate on the coastal waters of Bayelsa State, Nigeria. In this project, a floating pontoon, a gangway, and other supporting structures like scantlings and spud pillars, were designed to meet the needs and environmental requirements of the area. Standards consulted are the DNV Rules for the classification of ships; DNV Rules for the classification of Floating Docks; ABS Rules for Building and Classing Steel Barges; and other relevant Nigeria and Imo standards. The pontoon designed has dimensions: 13 x 12 x 4.8 m; gross tonnage of 15 tonnes; 2nos. of dry tanks of capacity 17.2 m³ and 6nos. of manholes of 450 x 550 mm. The strength of materials analysis was limited to the floating pontoon for limitations of space for this paper. The pontoon and scantling design has been done based on the worst condition of design pressure which is for the maximum submersion draft. Normal grade steel of yield strength 235 MPa is chosen for all members except the pontoon girders, frames and pillars. This is to reduce the material scantlings and to ensure higher strength with lesser scantlings. Longitudinal framing is adopted in the pontoons as the pontoon structure needs more strength in the longitudinal direction.

APA, Harvard, Vancouver, ISO, and other styles

8

Connell, Sean D. "Floating pontoons create novel habitats for subtidal epibiota." Journal of Experimental Marine Biology and Ecology 247, no. 2 (May 2000): 183–94. http://dx.doi.org/10.1016/s0022-0981(00)00147-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Fan, Hongjun, Jianyong Xu, Shunping Wu, Guozheng Shi, and Wenfeng Guan. "LNG bunkering pontoons on inland waters in China." Natural Gas Industry B 5, no. 2 (March 2018): 148–55. http://dx.doi.org/10.1016/j.ngib.2018.04.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Li, Kai, Zhichao Zhao, Songliang Chang, Jiawei Bao, Zhijiang Yuan, and Xiaogang Jiang. "RESEARCH ON DAMAGE CHARACTERISTICS AND PROTECTIVE STRUCTURE DESIGN OF STEEL PONTOONS UNDER NEAR-FIELD EXPLOSION LOAD." Brodogradnja 73, no. 4 (October 1, 2022): 53–77. http://dx.doi.org/10.21278/brod73404.

Full text

Abstract:

The focus of this paper is to investigate the damage characteristics and protective structure design of pontoons as an important barrier for the protection of ports. Two types of protective measures of pontoons are investigated：filling tanks with water and installing springs in tanks. In this paper, the damage characteristics of two types of pontoon side structures under the action of near-field explosion loads are simulated by using LS-DYNA explicit dynamic analysis software and the ALE algorithm. According to the numerical experiment results for filling different volumes of water in the side tanks, the volume of water for the minimum deformation of the shell plate is 100%, and for the first longitudinal bulkhead, it is 30-40%. Moreover, by applying weights to their deformations based on the actual explosion-proof performance requirements of the shell plate and the first longitudinal bulkhead, the pontoon side structure with the best explosion-proof performance can be obtained. The plastic deformation of the pontoon structure equipped with different types of springs is an order of magnitude smaller than that of the ordinary structure and of the pontoon structure filled with a water medium in the positive tanks. The explosive shock wave energy absorbed by the pontoon is effectively reduced by the addition of water or springs to the protective tanks. The minimum energy absorbed by the pontoon structure with water added in the protective tanks is 18.31% of the energy absorbed by the ordinary structure, and the corresponding volume ratio of water added in the protective tanks is 100%. The pontoon structure with springs in the side protection tanks absorbs only 7.2% of the energy absorbed by the ordinary structure. Both new side protection structures have demonstrated excellent explosion-proof performance.

APA, Harvard, Vancouver, ISO, and other styles

11

Power, Cecilia, Shannon Evenden, Kirsten Rough, Claire Webber, Maree Widdicombe, Barbara F. Nowak, and Nathan J. Bott. "Prevalence and Intensity of Cardicola spp. Infection in Ranched Southern Bluefin Tuna and a Comparison of Diagnostic Methods." Pathogens 10, no. 10 (September 27, 2021): 1248. http://dx.doi.org/10.3390/pathogens10101248.

Full text

Abstract:

The parasitic blood flukes Cardicola forsteri and C. orientalis are an ongoing health concern for Southern Bluefin Tuna Thunnus maccoyii (SBT) ranched in Australia. In this study we compared the effect of treatment, company, and ranching year on blood fluke infections in ranched SBT. SBT were sampled during the 2018 and 2019 ranching seasons from praziquantel (PZQ) treated pontoons and untreated pontoons managed by two companies. Severity of infection was diagnosed by several criteria including adult fluke counts from hearts, egg counts from gill filaments and the use of specific quantitative polymerase chain reaction (qPCR) for detection of C. forsteri and C. orientalis ITS-2 DNA in SBT hearts and gills. PZQ treatment remains highly effective against C. forsteri infection. Prevalence and intensity of Cardicola spp. infection was lower in 2019 than 2018 for Company A in treated pontoons at week 12 and week 17 of ranching, and lower for Company A than Company B in untreated pontoons at month 5 of ranching. Results indicate re-infection may be less likely in the environment near Company A pontoons, and consistent years of treatment may have lowered the parasite load in the environment. qPCR demonstrated higher sensitivity when comparing diagnostic methods for C. forsteri in heart, and higher specificity when comparing diagnostic methods for Cardicola spp. in gills. Continuing to monitor blood fluke infections in ranched SBT can help to detect changes in drug efficacy over time and help industry to develop a best practice for treatment.

APA, Harvard, Vancouver, ISO, and other styles

12

Qiu, Bo, and Zhi Hong Jin. "A Simulation Based Analysis on Setting Pontoons in a Regional Container Hub Port." Applied Mechanics and Materials 505-506 (January 2014): 884–93. http://dx.doi.org/10.4028/www.scientific.net/amm.505-506.884.

Full text

Abstract:

Dock congestion has been becoming increasingly troublesome problem in some regional hub ports in China, resulting in additional operational costs to feeder line shipping companies. To reduce the waiting times at the hub and to lower the operational cost, some companies place a pontoon close to the hub port as floating container terminal to berth smaller containerships. We discuss the justification for setting pontoons close to the hub from the viewpoint of a shipping company, propose a berthing decision model and describe a modified genetic algorithm to optimize the process. Simulation tests show that pontoon setting and rational scheduling can greatly alleviate congestion at the regional hub.

APA, Harvard, Vancouver, ISO, and other styles

13

Chen, Yong-kun, Yong Liu, and Domenico D. Meringolo. "Comparison of Hydrodynamic Performances Between Single Pontoon and Double Pontoon Floating Breakwaters Through the SPH Method." China Ocean Engineering 36, no. 6 (December 2022): 894–910. http://dx.doi.org/10.1007/s13344-022-0078-8.

Full text

Abstract:

AbstractA numerical study adopting the 2D δ-SPH model is performed to compare the hydrodynamic characteristics of a single pontoon floating breakwater and a double pontoon floating breakwater. Numerical simulations are performed using the δ-SPH model and experimental tests are conducted to validate the numerical model. The numerical results of both the free surface elevations and motions of the floating breakwater are in good agreement with the experimental results. Numerical results show that when the pontoon drafts are larger, the double pontoon floating breakwater performs better in wave attenuations compared with the single pontoon floating breakwater, and for all the drafts, the amplitudes of motions including sway, heave and roll of the double pontoon floating breakwater is always smaller. In addition, increasing the spacing between the two pontoons can further reduce the amplitudes of pontoon motions and improve the wave attenuation ability of the double pontoon floating breakwater.

APA, Harvard, Vancouver, ISO, and other styles

14

Reiso, Marit, Stine Fossbakken, Tore Helge Søreide, Anders Myhr, Vegard Berge Kristensen, Jon Solemsli, Jorunn Hillestad Sekse, and Arianna Minoretti. "Vertical stiffness for tube bridges: Comparing pontoons and tethers." IABSE Symposium Report 105, no. 2 (September 23, 2015): 1–8. http://dx.doi.org/10.2749/222137815818203944.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

YOSHIDA, Shoichi, Kazuhiro KITAMURA, and Tomoki MATSUMURA. "264 Buckling of Ring Stiffened Pontoons of Floating Roofs." Proceedings of the Dynamics & Design Conference 2006 (2006): _264–1_—_264–6_. http://dx.doi.org/10.1299/jsmedmc.2006._264-1_.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Jun, Zhang, Jun Liu, Xiao Lu Ni, Wei Li, and Rong Mu. "Dynamic Model of a Discrete-Pontoon Floating Bridge Subjected by Moving Loads." Applied Mechanics and Materials 29-32 (August 2010): 732–37. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.732.

Full text

Abstract:

A discrete-pontoon floating bridge is studied based on the beam model with assumption of the bridge deck as a elastic beam with uniform section, live load such as vehicle as moving concentrate forces, and pontoons as independent mass-spring-damping systems with singular degree of freedom. The comparison results of between vehicles and moving concentrated force show that a vehicle load can be simplified as one moving concentrated force. The present model can study not only a single moving load but also multiple moving loads.

APA, Harvard, Vancouver, ISO, and other styles

17

Szymczak-Graczyk, Anna. "Numerical Analysis of the Bottom Thickness of Closed Rectangular Tanks Used as Pontoons." Applied Sciences 10, no. 22 (November 15, 2020): 8082. http://dx.doi.org/10.3390/app10228082.

Full text

Abstract:

This paper concerns the numerical analysis of closed rectangular tanks made in one stage, used as pontoons. Such structures can be successfully used as floating platforms, although they primarily serve as floats for ‘houses on water’. Amphibious construction has fascinated designers for many years and is becoming, in addition to a great and prestigious location for many purposes, a practical global necessity. Severe weather phenomena that no country is safe from, i.e., heavy rains or floods, combined with the scarcity of space intended for the construction of residential buildings, encourage development at the contact of water and land or on water only. This paper contains an analysis of the static work of tanks with different bottom thickness subjected to hydrostatic load acting on tank walls and the bottom plate and evenly distributed load acting on the upper plate, i.e., major impacts that occur when tanks are used as pontoons. Calculations were made using the finite difference method in terms of energy, assuming the Poisson’s ratio ν = 0. Based on the solutions obtained, charts were made that illustrated the change in bending moments at the characteristic points of the analysed tanks depending on acting loads. The article also includes calculations of buoyancy, stability and the metacentric height for tanks with different bottom thicknesses, with the main purpose being to improve and share knowledge on their safe use as pontoons.

APA, Harvard, Vancouver, ISO, and other styles

18

Liu, Yuliang, and Takeshi Ishihara. "Numerical Study on Sectional Loads and Structural Optimization of an Elastic Semi-Submersible Floating Platform." Energies 14, no. 1 (December 31, 2020): 182. http://dx.doi.org/10.3390/en14010182.

Full text

Abstract:

This study investigates the sectional loads on an elastic semi-submersible platform for a 2 MW FOWT (floating offshore wind turbine) used in the Fukushima demonstration project. A water tank test is firstly carried out with an elastic model to study the dynamic responses and sectional loads of the platform in regular and irregular waves. Numerical simulations are then performed using multiple hydrodynamic bodies connected by elastic beams. The dynamic responses of the elastic model are compared to those of a rigid model to clarify the influence of the structural stiffness on the platform motion and mooring tension. The predicted sectional loads on the deck, brace and pontoon by the proposed nonlinear hydrodynamic models show good agreement with the experimental data obtained from the water tank test and a simplified formula is proposed to evaluate the distribution of the moments on the platform. Finally, the structural optimization of the elastic semi-submersible platform is conducted. The sectional moments and fatigue loadings on the pontoons are significantly reduced using the strut between the pontoons since the horizontal wave loads on the side column are dominant and the vertical wave loads acting on the platform are relatively small due to the deep draft.

APA, Harvard, Vancouver, ISO, and other styles

19

Abul-Azm, A. G., and M. R. Gesraha. "Approximation to the hydrodynamics of floating pontoons under oblique waves." Ocean Engineering 27, no. 4 (April 2000): 365–84. http://dx.doi.org/10.1016/s0029-8018(98)00057-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Toh, Kok Ben, Chin Soon Lionel Ng, Bokai Wu, Tai Chong Toh, Pei Rong Cheo, Karenne Tun, and Loke Ming Chou. "Spatial variability of epibiotic assemblages on marina pontoons in Singapore." Urban Ecosystems 20, no. 1 (August 12, 2016): 183–97. http://dx.doi.org/10.1007/s11252-016-0589-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Sukach, Mykhailo. "Deepwater Well Survey Equipment." Gіrnichі, budіvelnі, dorozhnі ta melіorativnі mashini, no. 98 (December 30, 2021): 21–29. http://dx.doi.org/10.32347/gbdmm.2021.98.0301.

Full text

Abstract:

With the growth in underwater construction activities, there is an increasing need for accurate seabed engineering data. Modern technology makes it possible to take samples of bottom soils with a partially disturbed structure, especially for weak silty soils and silts. Testing such samples in laboratory conditions leads to inevitable errors. Despite the constant improvement of technical means of sampling, they cannot fully replace studies of the properties of bottom soils in natural occurrence. Therefore, it became necessary to create devices for the natural study of underwater soils. The following soil investigation methods are used in deep-sea wells: stamp tests, rotational shear, penetration logging, soil cutting, pressuremetry. Drilling of underwater wells at the bottom is carried out from floating drilling rigs, consisting of a floating base and a drilling rig. Pontoons (catamarans, trimarans) and drilling ships (self-propelled and non-self-propelled) are used as a base. On the shelf, pontoons with retractable supports or a flooded base are more often used. The drilling rig with working equipment is usually placed in the center of the pontoon. The choice of drilling equipment is determined by the purpose of the work, the depth and diameter of underwater wells, the depth of the sea, the displacement of the drilling rig, the physical and mechanical properties of bottom, soil, etc. Deep-sea drilling is carried out from special vessels on which the drilling unit is mounted. Vessels with an opening bottom or a special shaft for the passage of casing and drill pipes, as well as those with retractable cantilever platforms, are used. Drilling ships and pontoons are kept in a fixed position with the help of four or six anchors attached to the bow and stern of the craft. Drilling rigs provide rotary, percussion-rotary, shock-rope, vibration, rotary suction and airlift drilling. Drilling at maximum depths in the ocean is carried out using deep-sea bottom platforms and autonomous controlled vehicles.

APA, Harvard, Vancouver, ISO, and other styles

22

Lin, Shueei-Muh, Chihng-Tsung Liauh, and Didi-Widya Utama. "Design and Dynamic Stability Analysis of a Submersible Ocean Current Generator Platform Mooring System under Typhoon Irregular Wave." Journal of Marine Science and Engineering 10, no. 4 (April 14, 2022): 538. http://dx.doi.org/10.3390/jmse10040538.

Full text

Abstract:

This research proposes a mooring system for an ocean current generator that is working under the impact of typhoon waves. The turbine and the platform are kept stable at a designed water depth to ensure that the generator remains undamaged and continuously generates electricity under excessive water pressure. In this design, the turbine generator is mounted in front of the floating platform by ropes and withstands the force of ocean currents, while the platform is anchored to the deep seabed with lightweight, high-strength PE ropes. In addition, two pontoons are used to connect the generator and the platform with ropes. When the balance is reached, the depth of the generator and the depth of the platform’s dive can be determined by the length of the ropes. In this study, typhoon irregular wave is represented by the Jonswap wave spectrum. The irregular wave is simulated by six regular waves. The equation of motion of the mooring system is derived. The theoretical solution of the dynamic system is presented to determine the dynamic displacements of the platform, pontoon, turbine and the dynamic tensions of the ropes. The dynamic tensions of the ropes increase with the cross-sectional area of pontoon. The natural frequency of the mooring system depends on the parameters, including the mases of elements, the lengths of ropes and the cross-sectional area of pontoons. In the proposed mooring configuration, the dynamic tension of the rope is far less than the breaking strength of the rope; thus, the ocean turbine is stable, and no water that flows through will be disturbed by the floating platform.

APA, Harvard, Vancouver, ISO, and other styles

23

Suzuki, Hideyuki, Hiroki Shiohara, Anja Schnepf, Hidetaka Houtani, Lucas H. S. Carmo, Shinichiro Hirabayashi, Ken Haneda, et al. "Wave and Wind Responses of a Very-Light FOWT with Guy-Wired-Supported Tower: Numerical and Experimental Studies." Journal of Marine Science and Engineering 8, no. 11 (October 26, 2020): 841. http://dx.doi.org/10.3390/jmse8110841.

Full text

Abstract:

A floating offshore wind turbine (FOWT) concept with a guy-wire-supported tower was investigated to obtain motion results in waves considering its elastic model characteristics. The FOWT concept studied aims to reduce the construction costs by using a light-weight structure tensioned with guy wires and a downwind type. Wave tank experiments of an elastically similar segmented backbone model in the 1:60 scale were carried out to clarify the dynamic elastic response features of the structure. The experimental results were compared with numerical simulations obtained from NK-UTWind and WAMIT codes. The bending moment measured at the tower and pontoons had two peak values for different wave periods carried out. The short-wave period peak was due to sagging/hogging when the wavelength matched the floater length. The second peak was due to the large tower top acceleration, which caused a large bending moment at the tower base and pontoon to support the inertia force. The wind force was not significant to modify the FOWT response. The sensibility analysis in pontoons and tower rigidities confirmed the importance of the guy wires to support the inertia due to the waves and wind incidence. The new concept of a very-light FOWT with a guy-wire-supported tower may be an option for future FOWT developments.

APA, Harvard, Vancouver, ISO, and other styles

24

Harrington, K. E., R. Hansen, A. L. Marshall, and M. Hubert. "The Weight of Concrete Barge and Pontoon Hulls." Marine Technology and SNAME News 28, no. 04 (July 1, 1991): 213–22. http://dx.doi.org/10.5957/mt1.1991.28.4.213.

Full text

Abstract:

Increased structural weight has always been a major disadvantage and probably the main objection to using concrete hulls. Postwar development in materials and construction techniques has led to claims that it is now possible to achieve structural weights equalling or closely approaching those of equivalent steel hulls. After reviewing the postwar material and construction technique developments, this paper compares the structural weight of existing and equivalent steel and concrete barge and pontoon hull designs. It is found that increased structural weight is a dual factor advantageous in some applications but disadvantageous in others, and that despite the postwar developments concrete barges and pontoons are still heavier than equivalent steel hulls.

APA, Harvard, Vancouver, ISO, and other styles

25

Myatt, Lisa L., Brian Thomas, and Todd Taylor. "Impact of Pontoon Vessel Geometry on Allowable Passenger Weight Using USCG Pontoon Simplified Stability Test." Journal of Ship Production and Design 26, no. 02 (May 1, 2010): 135–43. http://dx.doi.org/10.5957/jspd.2010.26.2.135.

Full text

Abstract:

A parametric analysis of stability was performed for more than 30,000 geometric variants of cylindrical-hulled pontoon vessels to quantify the impacts of vessel geometry and prepassenger displacement on the maximum passenger weight allowed by the US Coast Guard (USCG) Pontoon Simplified Stability Test (PSST). Variables examined included pontoon diameter, pontoon length, pontoon separation, deck height, passenger deck width, location of forward and aft edges of the passenger deck, prepassenger displacement prior to loading, and trim. Each pontoon vessel variant was evaluated using General Hydrostatics Software to apply the PSST to determine the maximum passenger weight allowed for that vessel. Graphical analysis of the data demonstrated that a vessel's allowable passenger weight increases with: an increased pontoon diameter or length of pontoon, a decreased deck height, a limited increase in pontoon separation or beam ratio, and a symmetrically decreased passenger deck width or length. Additionally, it was found that each specific vessel has an optimum prepassenger displacement, unique to its pontoon diameter and length of pontoons, which maximizes the allowable passenger weight. Finally, a method is provided to correlate the present results with prior related work by other authors that characterized pontoon vessel stability in the context of pontoon percent submergence.

APA, Harvard, Vancouver, ISO, and other styles

26

SAENZ-ARIAS, PABLO, CARLOS NAVARRO-BARRANCO, and JOSÉ MANUEL GUERRA-GARCÍA. "Influence of environmental factors and sessile biota on vagile epibionts: The case of amphipods in marinas across a regional scale." Mediterranean Marine Science 23, no. 1 (January 26, 2022): 1. http://dx.doi.org/10.12681/mms.26800.

Full text

Abstract:

Marinas are highly anthropized environments, with singular ecological characteristics. In the present study the spatial variability of the amphipod assemblage associated to floating pontoons was analyzed. Moreover, the influence of the environmental data and the sessile biota on the amphipod assemblage structure were assessed. Six marinas were selected along the Southern Iberian Peninsula, three in the Atlantic and three in the Mediterranean, and three floating pontoons were sampled at each marina. Four-teen amphipod species were identified, most of them corresponded to detritivores and generalist species. Statistical analyses considering amphipod composition and abundance did not show significant differences between the Atlantic and the Mediterranean, but there were significant differences among marinas. Copper had a significant correlation with the amphipod assemblage. The sessile species Bugula neritina and Ellisolandia elongata also showed a significant influence on the spatial patterns of the amphipod assemblages. Therefore, environmental conditions and sessile composition seem to affect, simultaneously, the spatial variability of amphipod assemblage associated to floating pontoons in marinas. Both factors are key to understand the singularity of marinas. This fact should be taken into consideration to prevent the use of a single management program in these environments.

APA, Harvard, Vancouver, ISO, and other styles

27

Wang, Shuqing, Yijun Cao, Qiang Fu, and Huajun Li. "Hydrodynamic performance of a novel semi-submersible platform with nonsymmetrical pontoons." Ocean Engineering 110 (December 2015): 106–15. http://dx.doi.org/10.1016/j.oceaneng.2015.10.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Cong, PeiWen, Ying Gou, and Bin Teng. "Effect of pontoons on free surface elevation around a TLP platform." Science China Technological Sciences 57, no. 1 (December 26, 2013): 163–80. http://dx.doi.org/10.1007/s11431-013-5388-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Cherdantsev, S. V. "Theoretical basis for calculation of pontoons used in open pit mines." Journal of Mining Science 49, no. 1 (January 2013): 52–59. http://dx.doi.org/10.1134/s1062739149010073.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Karavaichenko, Mikhail G., Alexander V. Vasiliev, and Rustam I. Galimzyanov. "Strength, rigidity and buoyancy analysis for pontoons in vertical cylindrical tanks." SCIENCE & TECHNOLOGIES OIL AND OIL PRODUCTS PIPELINE TRANSPORTATION 9, no. 6 (November 30, 2019): 626–32. http://dx.doi.org/10.28999/2541-9595-2019-9-6-626-632.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Yu Pechenkina, M., and O. A. Nasibullina. "Prevention of local corrosion of aluminum alloy pontoons in steel tanks." Journal of Physics: Conference Series 2373, no. 2 (December 1, 2022): 022070. http://dx.doi.org/10.1088/1742-6596/2373/2/022070.

Full text

Abstract:

Abstract Over the years of existence of the oil and gas industry, increasing the efficiency of equipment at production facilities places increasing demands on operational reliability and durability. The use of aluminum alloys is due to a large range of its features and properties, one of which is the combination of high strength in combination with low density, sufficient corrosion resistance, good moulding ability by casting, pressure and cutting, the possibility of using aluminum parts in all kinds of structures by welding, soldering and other methods. It is important to bear in mind that aluminium alloys do not require regular corrosion coating during operation. It is all about the finest and extremely strong oxide film (0.00001 mm), which forms a reliable adhesion to the metal.

APA, Harvard, Vancouver, ISO, and other styles

32

Khalifa, Yasser A., Mohamed N. Lotfy, and Elsayed Fathallah. "Effectiveness of Sacrificial Shielding for Blast Mitigation of Steel Floating Pontoons." Journal of Marine Science and Engineering 11, no. 1 (January 4, 2023): 96. http://dx.doi.org/10.3390/jmse11010096.

Full text

Abstract:

Floating pontoons have played a supreme and indispensable role in crises and disasters for both civil and military purposes. Floating bridges and ferries are exposed to blast loadings in the case of wars or terrorist attacks. The protection effectiveness of sacrificial cladding subjected to a blast was numerically investigated. In this study, a steel ferry has been simulated and exposed to side explosions with different explosive charges at certain stand-off distances, according to military standards from NATO and American standard TM5. In this simulation, nonlinear three-dimensional hydro-code numerical simulation ANSYS autodyn-3d has been used. The results reported that the ferry could withstand a charge of 5 kg TNT at a stand-off distance of 1 m without failure. The main objective of this research is to achieve a design that would increase the capacity against the blast loading with minimal plastic deformation in the absence of any failure in the ferry. Therefore, an innovative mitigation system has been proposed to dissipate the blast energy of the explosion based on the scientific theory of impedance using sacrificial cladding. The new mitigation system used a specific structural system in order to install the existing pontoon structure without any distraction. The response, elastic deformations, plastic deformations and plastic failure of the ferry were illustrated in this paper. Furthermore, the results revealed that the proposed mitigation system could mitigate more than 50% of the blast waves. The new design revealed promising results, which makes it suitable for mitigating blast waves. Finally, the results were provided with a reference for the preliminary design and application of sacrificial cladding for structural protection against blast waves.

APA, Harvard, Vancouver, ISO, and other styles

33

Hammond, N. G. L., and L. J. Roseman. "The construction of Xerxes' bridge over the Hellespont." Journal of Hellenic Studies 116 (November 1996): 88–107. http://dx.doi.org/10.2307/631957.

Full text

Abstract:

The bridging of the Hellespont by Xerxes was a unique achievement. How was it done? The Chorus of Elders in Aeschylus' Persians expressed their wonder at ‘the flax-bound raft’, and Herodotus described the construction of the two bridges, each with warships as pontoons, with cables well over a kilometre long, and with a roadway capable of carrying a huge army. Classical scholars have generally found these accounts inadequate and even inexplicable, especially in regard to the relationship between the pontoons and the cables. The Hellespont has strong currents which vary in their direction, turbulent and often stormy waters, and exposure to violent winds, blowing sometimes from the Black Sea and sometimes from the Mediterranean. How were the warships moored in order to face the currents and withstand the gales? Did the warships form a continuous platform, or was each ship free to move in response to weather conditions? What was the function of the enormous cables? How and where were they made? Did they bind the pontoons together? Did they carry the roadway? How were they fixed at the landward ends? This article attempts an answer to these questions through the collaboration of a classical scholar and a mechanical engineer.

APA, Harvard, Vancouver, ISO, and other styles

34

Mullarkey, T. P., and J. F. McNamara. "Semi-Analytical Hydrodynamics and Motions for a TLP Structure—Part I: Enhancement of Pontoon Results Using Two of Haskind’s Theorems." Journal of Offshore Mechanics and Arctic Engineering 119, no. 3 (August 1, 1997): 166–77. http://dx.doi.org/10.1115/1.2829064.

Full text

Abstract:

A semi-analytical solution procedure for the derivation of first-order wave forces, added mass, and damping terms is presented for rectangular pontoons which may be floating, submerged, or resting on the seabed. The development is based on a solution matching technique for the scattered and radiated wave potentials and gradients across common boundaries of the subdivided solution domain. The final expressions are true for waves of arbitrary angle of incidence and singularities due to the case of normal incidence are eliminated. The approach is also generalized for the case where the pontoon is a unit of a TLP offshore production system by referring all quantities to a global coordinate system. Numerical results are extracted for a number of benchmark problems and compared with independent values where available in the literature. Excellent agreement is obtained for wave forces, added mass, and damping Values for cases involving floating, submerged, and bottom-founded pontoon configurations.

APA, Harvard, Vancouver, ISO, and other styles

35

Huang, Guoxing, Yue Song, Ningchuan Zhang, and Xianying Shi. "Experimental Study of Optimizing the Mooring Configuration of the Tunnel-Pontoons System." International Journal of Offshore and Polar Engineering 27, no. 3 (September 1, 2017): 301–9. http://dx.doi.org/10.17736/ijope.2017.sh16.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Tabatabaei, Seyyed Mohammad Reza, and Hamid Zeraatgar. "Parametric Comparison of Rectangular and Circular Pontoons Performance as Floating Breakwater Numerically." Polish Maritime Research 25, s1 (May 1, 2018): 94–103. http://dx.doi.org/10.2478/pomr-2018-0029.

Full text

Abstract:

Abstract Rectangular and circular pontoons are one of the most widely cross-sections used as floating breakwaters (FB). Although, there are several articles on comparison of behavior of rectangular and circular floating breakwaters however, the Authors try to show some details of difference between these two types where they have not been addressed before. To do so, transmission coefficient (Ct), as a measure of merit, of similar rectangular and circular sections is numerically compared. A computer code is developed for two-dimensional hydrodynamic analysis of floating breakwater based on diffraction theory in frequency domain in regular waves with any configuration of mooring line. The numerical method is the finite element method and validated by comparing with experimental and numerical results. Three types of rectangular sections are defined equivalent to circular section and a numerical comparison is made between 100 similar sections. The Ct versus wave frequency has been considered in detail and three new points called LMinF, LMaxF and LMaxCt are introduced. It has been shown that LMinF and LMaxF of circular section are greater and LMaxCt is much smaller than equivalent rectangular section. The LMaxCt of both sections are very dependent to new non-dimensional parameter B/D (Breadth/Draft). Although, rectangular sections are more common for floating breakwater, however the results of this study show that possibility of using circular sections must be also considered.

APA, Harvard, Vancouver, ISO, and other styles

37

Gesraha, Mohamed R. "An eigenfunction expansion solution for extremely flexible floating pontoons in oblique waves." Applied Ocean Research 26, no. 5 (July 2004): 171–82. http://dx.doi.org/10.1016/j.apor.2005.05.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Lin, Shueei-Muh, Yang-Yih Chen, and Chihng-Tsung Liauh. "Dynamic Stability of the Coupled Pontoon-Ocean Turbine-Floater Platform-Rope System under Harmonic Wave Excitation and Steady Ocean Current." Journal of Marine Science and Engineering 9, no. 12 (December 13, 2021): 1425. http://dx.doi.org/10.3390/jmse9121425.

Full text

Abstract:

This research proposes a mooring design which keeps the turbine ocean current, static, balanced, and fixed at a predetermined depth under water, to ensure that the ocean current generator can effectively use current to generate electricity, and that the water pressure remains adequate value before critical pressure damage occurs. In this design, the turbine generator, which withstands the force of ocean currents, is mounted in front of a floating platform by ropes, and the platform is anchored to the deep seabed with light-weight high-strength PE ropes. In addition, a pontoon is connected to the ocean current generator with a rope. The balance is reached by the ocean current generator weight, floating pontoon, and the tension of the ropes which are connected between the generator and floating platform. Therefore, both horizontal and vertical forces become static and the depth can be determined by the length of the rope. Because the floating platform and pontoons on the water surface are significantly affected by waves, the two devices subjected to the wave exciting forces are further affected by the movement of the platform, pontoons, turbines, and the tensions of the ropes. Among them, the exciting forces depend on the operating volume of the two devices. Moreover, there is a phase difference between the floating platform and the pontoon under the action of the waves. In this study, the linear elastic model is used to simulate the motion equation of the overall mooring system. A theoretical solution of the static and dynamic stability analysis of the mooring system is proposed. The dynamic behaviors of the turbine, the floating platform, the pontoon, and the tension of the rope under the effects of waves and ocean currents are investigated. The study found the relationship of the phase difference and the direction difference of waves and ocean currents, the wavelength, and the length of the rope between the carrier and the turbine. It was found that the phase difference has a great influence on the dynamic behaviors of the system. The length of the rope can be adjusted to avoid resonance and reduce the rope tension. In addition, a buffer spring can be used to reduce the dynamic tension of the rope significantly to ensure the safety and life of the rope.

APA, Harvard, Vancouver, ISO, and other styles

39

Murali, K., S. S. Amer, and J. S. Mani. "Dynamics of Cage Floating Breakwater." Journal of Offshore Mechanics and Arctic Engineering 127, no. 4 (May 27, 2005): 331–39. http://dx.doi.org/10.1115/1.2073347.

Full text

Abstract:

Floating breakwaters have potential applications in protecting minor ports and harbors such as fisheries and recreational harbors, where-in stringent tranquillity requirements are not warranted. In field applications of the existing floating breakwaters, limitations are imposed due to their large relative width (ratio between breakwater width and wave length) requirements to achieve desirable tranquillity level. This relative width requirement is greater than 0.3 for the existing floating breakwaters. To overcome the above drawback associated with the existing system a new configuration for a floating breakwater is derived, which could yield the desired performance with minimum relative width requirement. The floating breakwater comprises of two pontoons rigidly connected together and each of the pontoons having a row of cylinders attached beneath, for improved performance characteristics. The laboratory tests were conducted in both regular and random wave flumes to study the dynamic behavior of the breakwater. Transmission and reflection coefficients, water surface elevations and velocities inside the cage like area provided in between the pontoons, rigid body motions floating breakwater and mooring forces were studied under regular and random waves and under the regular waves followed by a uniform current. The results proved the suitability of the floating breakwater to the field conditions even for large wave periods. In addition the variations in water particle kinematics, rigid body motion and mooring forces show nominal magnitudes when compared to the existing systems indicating the rigidness of the breakwater.

APA, Harvard, Vancouver, ISO, and other styles

40

Fitriadhy, A., S. F. Abdullah, M. Hairil, M. F. Ahmad, and A. Jusoh. "Optimized modelling on lateral separation of twin pontoon-net floating breakwater." Journal of Mechanical Engineering and Sciences 13, no. 4 (December 30, 2019): 5764–79. http://dx.doi.org/10.15282/jmes.13.4.2019.04.0460.

Full text

Abstract:

Since the attribute of wave energy transmission is susceptible to lateral separation (S/D) between twin pontoons of floating breakwater, employing improper S/D may cause ineffective attenuation in the amount of wave energy. This paper presents a numerical optimization modelling aimed at obtaining the optimum S/D through Genetic Algorithm (GA) approach. The artificial intelligence is primarily employed to minimize transmission of wave energy coefficients ( ) whereas maximize energy dissipation coefficient ( ). To achieve such demand, a numerical simulation implementing a MATLAB code as an interface between the Genetic Algorithm and a CFD program is applied. Several parameters for the effects of various wavelengths and ratios of S/D including a set of criteria have been considered in the simulation, where the optimum solution is chosen from various populations. The results demonstrated that the current GA analysis is efficient that can search a global trade-offs between and to determine an optimum S/D. The was minimized to less than 0.3 as compared to existing model ( ) while maximizing to greater than 0.95. Hence, the optimisation algorithm can serve as a useful engineering tool for a conceptual design to determine an optimum S/D for twin pontoons of floating breakwater.

APA, Harvard, Vancouver, ISO, and other styles

41

Chalmers, Peggy. "Feature Focus: Offshore Innovations: Raising the Kursk." Mechanical Engineering 124, no. 05 (May 1, 2002): 52–55. http://dx.doi.org/10.1115/1.2002-may-3.

Full text

Abstract:

This article reviews the 10,000-metric-ton Russian nuclear submarine Kursk, with two nuclear reactors and 20 missiles aboard, had gone down in August 2000 following a pair of explosions approximately two minutes apart. Explosions had left the bow so deformed it was impossible to attach lifting devices, and there were serious doubts about the structural integrity of what remained. At Roslyakovo, the 21-tonne Giant was lifted clear of the water by two auxiliary pontoons. The pontoons, 100 meters long with a 15-meter beam, were sunk below the barge, winched into position beneath it, and then pumped out in order to raise the Giant-Kursk combination. This extra lift, in addition to deballasting of the drydock, provided the clearance the strand jacks needed to lower the sub on the stocks. Once the Kursk was positioned, the Giant 4 released its load and was withdrawn from the drydock.

APA, Harvard, Vancouver, ISO, and other styles

42

Peng, Wei, Yingnan Zhang, Xueer Yang, Jisheng Zhang, Rui He, Yanjun Liu, and Renwen Chen. "Hydrodynamic Performance of a Hybrid System Combining a Fixed Breakwater and a Wave Energy Converter: An Experimental Study." Energies 13, no. 21 (November 2, 2020): 5740. http://dx.doi.org/10.3390/en13215740.

Full text

Abstract:

In this paper, a hybrid system integrating a fixed breakwater and an oscillating buoy type wave energy converter (WEC) is introduced. The energy converter is designed to extract the wave power by making use of the wave-induced heave motions of the three floating pontoons in front of the fixed breakwater. A preliminary experimental study is carried out to discuss the hydrodynamic performance of the hybrid system under the action of regular waves. A scale model was built in the laboratory at Hohai University, and the dissipative force from racks and gearboxes and the Ampere force from dynamos were employed as the power take-off (PTO) damping source. During the experiments, variations in numbers of key parameters, including the wave elevation, free response or damped motion of the floating pontoons, and the voltage output of the dynamos were simultaneously measured. Results indicate that the wave overtopping and breaking occurring on the upper surfaces of floating pontoons have a significant influence on the hydrodynamic performance of the system. For moderate and longer waves, the developed system proves to be effective in attenuating the incident energy, with less than 30% of the energy reflected back to the paddle. More importantly, the hydrodynamic efficiency of energy conversion for the present device can achieve approximately 19.6% at the lowest wave steepness in the model tests, implying that although the WEC model harnesses more energy in more energetic seas, the device may be more efficient for wave power extraction in a less energetic sea-state.

APA, Harvard, Vancouver, ISO, and other styles

43

Minchin, Dan. "Rapid coastal survey for targeted alien species associated with floating pontoons in Ireland." Aquatic Invasions 2, no. 1 (2007): 63–70. http://dx.doi.org/10.3391/ai.2007.2.1.8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Zhao, Xuanlie, and Dezhi Ning. "Experimental investigation of breakwater-type WEC composed of both stationary and floating pontoons." Energy 155 (July 2018): 226–33. http://dx.doi.org/10.1016/j.energy.2018.04.189.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Waltham, Nathan J., Michael Bradley, Saara Wilson, Kevin Kane, Odette Langham, and Marcus Sheaves. "Remotely operated vehicle reveals fish orientate to the substrate underneath marina floating pontoons." Estuarine, Coastal and Shelf Science 280 (January 2023): 108184. http://dx.doi.org/10.1016/j.ecss.2022.108184.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Ning, Dezhi, Xuanlie Zhao, Ming Zhao, and Haigui Kang. "Experimental investigation on hydrodynamic performance of a dual pontoon–power take-off type wave energy converter integrated with floating breakwaters." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, no. 4 (October 7, 2018): 991–99. http://dx.doi.org/10.1177/1475090218804677.

Full text

Abstract:

As an extension of the single pontoon wave energy converter–type breakwater, a wave energy converter–type breakwater equipped with dual pontoon–power take-off system is proposed to broaden the effective frequency range (for transmission coefficient KT < 0.5 and capture width ratio η > 20%). The wave energy converter–type breakwater with dual pontoon–power take-off system consists of a pair of heave-type pontoons and power take-off systems for which the power take-off system is installed to harvest the kinetic energy of heave motion of the pontoon. In this paper, we experimentally confirm the advantage of the wave energy converter–type breakwater with dual pontoon–power take-off system over the one with a single pontoon–power take-off system. Both wave energy converter–type breakwater with dual pontoon–power take-off system and that with single pontoon–power take-off system are tested in regular waves. A (electronic) current controller–magnetic powder brake system is used to simulate the power take-off system. The characteristics of power take-off system are investigated and results showed that the power take-off system can simulate the (approximate) Coulomb damping force well. Experimental results reveal that the wave energy converter–type breakwater with dual pontoon–power take-off system broadens the effective frequency range compared with the single pontoon–power take-off system with the same pontoon volume (i.e. the displacement of the pontoon). Specifically, the transmission coefficient of the system is smaller while the system in relative longer waves. Furthermore, the capture width ratio of system can be improved.

APA, Harvard, Vancouver, ISO, and other styles

47

Novak, Jeremiah. "Is NATO Necessary?" Worldview 28, no. 4 (April 1985): 18–22. http://dx.doi.org/10.1017/s0084255900045836.

Full text

Abstract:

Imagine the scene. A river running through a green valley. Under the trees, the river looks like a black-green stream. Pontoons are stretched across the surface, while long lines of tanks wait to cross—sixty-ton behemoths, with the menacing barrels of their 105 mm guns pointing at the opposite shore.

APA, Harvard, Vancouver, ISO, and other styles

48

Fenerci, Aksel, Knut Andreas Kvåle, Xu Xiang, and Ole Øiseth. "Hydrodynamic interaction of floating bridge pontoons and its effect on the bridge dynamic responses." Marine Structures 83 (May 2022): 103174. http://dx.doi.org/10.1016/j.marstruc.2022.103174.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Li, Jun-Jun, Bo-Wei Xu, and Hua-Feng Wu. "Modified quantum particle swarm optimization for translation control of immersed tunnel element with pontoons." Journal of Intelligent & Fuzzy Systems 36, no. 2 (March 16, 2019): 1073–81. http://dx.doi.org/10.3233/jifs-169882.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Zhang, Wenbin, and Mingxin Ye. "Dynamic analysis of autonomous risk avoidance of amphibious floating bridge based on discrete element method and physical engine." E3S Web of Conferences 261 (2021): 02020. http://dx.doi.org/10.1051/e3sconf/202126102020.

Full text

Abstract:

In this paper, based on an intelligent floating bridge, by using discrete element methods and physical engines, under the action of certain missile repulsion fields, the force process and motion path in the process of autonomous evasion of missiles are studied. Firstly, the static simulation of missile repulsion fields is carried out by using the polynomial least square surface fitting method. According to the strength of repulsion field at different times and the extrusion force between the pontoons, the kinematic equation of the pontoon is established. The equation is discretised by using a discrete element method, and the kinematic equation is obtained according to the time iteration. Then, motion analysis is carried out by using a physical engine on the basis of equation Analysis. Finally, the position parameters before and after the self-evasion missile of the floating bridge are calculated, and the simulation program is written in MATLAB. The dynamic simulation experiment of the whole evasion missile process is carried out, and the results are satisfactory.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Pontoons'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles