Ballast System Research Articles

Comparative Analysis of Installed and Actual Pump Power in Bilge and Ballast Systems: Study Case on 60 m Buoy Laying Vessel

Comparative Analysis of Installed and Actual Pump Power in Bilge and Ballast Systems: Study Case on 60 m Buoy Laying Vessel

Dynamic responses of the floatover system with nonstationary mating processes: An experimental study

Floatover method has been widely applied in the installation of both fixed and floating platforms, which has the advantages of high efficiency, economy, and large lifting capacity compared with other installation methods. Few studies could numerically and experimentally simulate the continuous load transfer process which shows significant nonstationary characteristics. This paper conducts experimental research on the nonstationary mating process of the floatover system. The ballasting system based on the control logic of feedback adjustment is developed to adjust the draft and inertia properties of the floatover vessel, and the validation tests are conducted to verify the feasibility and reliability of the system. The load buffer devices are designed carefully and the piecewise linear spring simulation method is applied to simulate the nonlinear stiffnesses of the elastic cushion. The stationary model for 0% and 100% load transfer stages and the nonstationary model for continuous load transfer process are established and tested in the model tests, and the dynamic responses are analyzed by using statistical and spectral methods respectively. Stationary model tests indicate that the spectral characteristics and distribution of LMU (Leg Mating Unit) dynamic loads in transverse symmetric positions are similar, and the statistical values are also relatively close under different wave heads. The nonstationary dynamic responses are segmented according to the physical process, time-frequency spectrum and piecewise statistics diagram to find the critical stage. The greatest dynamic load occurs in the intermediate stage of the mating process when the larger stiffness of the LMU acts and the steel-to-steel contact will also occur.

Sustainable solutions for railway using recycled rubber

This paper introduces four innovative applications of waste rubber from scrapped tyres or conveyor belts in railway tracks. They include (a) a synthetic energy-absorbing layer of coalwash, steel furnace slag and rubber crumbs (SFS + CW + RC) for railway subballast, (b) a rubber inter-mixed ballast system (RIBS), (c) energy-absorbing rubber geogrids, and (d) a hybrid track incorporating tyre cells and elements of off-the-road truck tyres. Comprehensive laboratory and field tests have been conducted to investigate the geotechnical properties of these applications. Specifically, an empirical model was developed to predict the permanent deformation response of SFS + CW + RC mixtures that incorporate the effect of granular rubber and axial loads based on cyclic triaxial tests. Large-scale triaxial tests and field trials proved that RIBS exhibited improved energy-absorbing properties, sufficient shear strength and the promising ability to mitigate ballast breakage and stress distribution. A rubber geogrid with an optimal rib thickness of 10.6 mm was selected based on drop-hammer impact tests. The performance of the hybrid track was investigated using the National Testing Facility for High-speed Rail (NTFHR), from which it was found that the reinforced track had significantly less settlement, lateral deformation and ballast breakage than the traditional track.

Effects of ballast transfer on modeling and dynamic responses of a 15MW semi-submersible floating wind turbine

The total ballast accounts for more than 60% of displacement for large-megawatt floating wind turbines (FWT), including fixed and adjustable ballast. Properly using and controlling the variable ballast is attractive to optimize the dynamic performance but is not well studied yet. This study aims to demonstrate and quantify the effects of ballast transfer on the dynamic behavior and performance of FWTs. A 15 MW semi-submersible FWT equipped with an appropriate ballast transfer system is modeled and numerically analyzed. A hydrostatic model is first established to calculate inertial and hydrostatic properties of the FWT during the ballast transfer. Fully coupled time-domain simulations with and without ballast transfer are then carried out to predict the wind turbine performance, platform motion, and structural responses under various environmental conditions. The results indicate that ballast transfer can change the hydrostatic and hydrodynamic properties of the FWT, with an increase of approximately 3.5% in pitch hydrostatic stiffness. In addition, the ballast transfer can increase the average power generation, reduce platform pitch and roll motions, and significantly decrease the hub thrust and the tower base bending moment. The insights obtained serve as a foundation for the development of active ballast systems and the optimization of FWT operation.

Point-to-Point-Based Optimization Method of Ballast Water Allocation for Revolving Floating Cranes with Experimental Verification

The Revolving Floating Crane (RFC) is a specialized engineering vessel crucial for offshore lifting operations, such as offshore platform construction and deep-water salvaging. It boasts impressive lifting capacity, good adaptability to various environmental conditions, and high operational efficiency. Conventionally, the safety and stability of RFC operations heavily depend on manual ballast water allocation, which is directly influenced by factors such as personnel status and sea conditions. These manual operations often result in reduced lifting efficiency, higher energy consumption, and compromised operational safety. In response, this paper introduces a ballast water-allocation approach based on the Point-to-Point (PTP) theory for the intelligent operation process of the RFC. The fundamental principles of the PTP theory are analyzed, and a method tailored to optimize ballast water allocation for RFC is proposed. Considering the unique characteristics of the ballast system and the specific requirements of lifting operations, an optimization model for PTP-based ballast water allocation is established. Numerical experiments are conducted to verify the efficacy and reliability of the proposed method. Comparing it to the conventional approaches, the results demonstrate a notable 17.75% reduction in energy consumption and an impressive 73.49% decrease in decision-making time, showcasing the superiority of the proposed approach. Finally, the engineering feasibility of the PTP-based optimization method for ballast water allocation is validated through actual lifting experiments, underscoring its potential to enhance RFC operations.

Reducing Operation Emissions and Improving Work Efficiency Using a Pure Electric Wheel Drive Tractor

In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field, a purely electric wheel-side drive tractor was studied, including an electric motor drive system, a battery ballast system, and an electro–hydraulic suspension system. This paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions, leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front- and rear-axle loads of a tractor. Finally, the tractor is prototyped and assembled, and ploughing tests are carried out. The ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83% and increases the traction efficiency by 10.28% compared with the average torque-distribution mode. Compared with the conventional traction control mode, the joint control method for traction and ballast proposed in this paper results in a 3.7% increase in traction efficiency, a 15.05% decrease in slip, and a 4.9% reduction in total drive motor energy consumption. This study will help to improve the operation quality and traction efficiency of electric tractors in complex soil conditions.

Electromyography-Based Biomechanical Cybernetic Control of a Robotic Fish Avatar

This study introduces a cybernetic control and architectural framework for a robotic fish avatar operated by a human. The behavior of the robot fish is influenced by the electromyographic (EMG) signals of the human operator, triggered by stimuli from the surrounding objects and scenery. A deep artificial neural network (ANN) with perceptrons classifies the EMG signals, discerning the type of muscular stimuli generated. The research unveils a fuzzy-based oscillation pattern generator (OPG) designed to emulate functions akin to a neural central pattern generator, producing coordinated fish undulations. The OPG generates swimming behavior as an oscillation function, decoupled into coordinated step signals, right and left, for a dual electromagnetic oscillator in the fish propulsion system. Furthermore, the research presents an underactuated biorobotic mechanism of the subcarangiform type comprising a two-solenoid electromagnetic oscillator, an antagonistic musculoskeletal elastic system of tendons, and a multi-link caudal spine composed of helical springs. The biomechanics dynamic model and control for swimming, as well as the ballasting system for submersion and buoyancy, are deduced. This study highlights the utilization of EMG measurements encompassing sampling time and μ-volt signals for both hands and all fingers. The subsequent feature extraction resulted in three types of statistical patterns, namely, Ω,γ,λ, serving as inputs for a multilayer feedforward neural network of perceptrons. The experimental findings quantified controlled movements, specifically caudal fin undulations during forward, right, and left turns, with a particular emphasis on the dynamics of caudal fin undulations of a robot prototype.

Ballast-Supported Foundation Designs for Low-Cost Open-Source Solar Photovoltaic Racking

Although solar photovoltaic (PV) system costs have declined, capital cost remains a barrier to widespread adoption. Do-it-yourself (DIY) system designs can significantly reduce labor costs, but if they are not attached to a building structure, they require ground penetrating footings. This is not technically and economically feasible at all sites. To overcome these challenges, this study details systems designed to (1) eliminate drilling holes and pouring concrete, (2) propose solutions for both fixed and variable tilt systems, (3) remain cost effective, and (4) allow for modifications to best fit the user’s needs. The ballast-supported foundations are analyzed for eight systems by proposing two separate ballast designs: one for a single line of post systems, and one for a double line of post systems, both built on a 4-kW basis. The results of the analysis found that both designs are slightly more expensive than typical in-ground concrete systems by 25% (assuming rocks are purchased at a landscaping company), but the overall DIY system’s costs remain economically advantageous. Sensitivity analyses are conducted to show how modifications to the dimensions influence the weight of the system and thus change the economic value of the design, so users can trade dimensional freedom for cost savings, and vice versa. Overall, all wood-based PV racking system designs provide users with cost-effective and easy DIY alternatives to conventional metal racking, and the novel ballast systems presented provide more versatility for PV systems installations.

Automated Deployment of an Underwater Tether Equipped with a Compliant Buoy–Ballast System for Remotely Operated Vehicle Intervention

Underwater remotely operated vehicles (ROVs) are linked to the surface through a tether that is usually controlled by a human operator. The length of the tether being deployed in the water in real time is a critical determinant of the success of the mission, and the problems of entanglement and cable stretching must be anticipated to the greatest possible extent. This paper describes a low-cost and setup-friendly solution for managing the length of a neutrally buoyant tether using a balanced buoy–ballast system implemented on the part of the tether proximal to the ROV. Embedded in the system is a curvature sensor that helps to control the cable feeder on the surface. This represents a useful solution for smoothing tether movements and to damp external disturbances. The results of experiments carried out in water tanks demonstrate the benefits of this solution in allowing the cable to maintain a semi-stretched shape while ensuring that the ROV avoids being pulled by the cable. Possible applications for a surface vehicle linked to an ROV through a tether equipped with this compliant buoy–ballast system include exploration or cartography missions in shallow waters.

Design proposal for a ballast treatment system to reduce the invasion of species in the Galapagos

Ballast water is necessary to maintain the stability of the vessels when loading and unloading their merchandise. However, it is also one of the main causes of species invasions in many ports around the world. The Galapagos Islands are no exception to this problem, since according to investigations several non-native species have been found due to ballast transport. Therefore, this project focused on the development of an alternative model for a ballast water treatment system using the chemical method to prevent the invasion of species in the Islands. As a result, two models were obtained. In the first, one NaClO dosing pump is used and in the second, two pumps are used. Each one of them was carried out from the Isla de la Plata ballast system and using RhinoCeros and AutoCAD software. In conclusion, after the modeling of both proposals and the technical analysis of the current ballast system of the vessel, it was determined that they comply with the provisions of the IMO and that they are the basis for the subsequent implementation of the alternatives.

Design of a submarine main ballast blowing systems

A submarine ballast system represents a combination of dedicated equipment and piping in which the main circulating fluid is either sea water straight from the submarine exterior or air which is compressed at high pressures and then it is stored in pressure vessels onboard. These fluids are, then, introduced in or extracted from various tanks located strategically onboard the submerged vehicle. Because water cannot be compressed and because of it’s density, it will require large amounts of energy and pumps to be able to move all the water within the system in a short period of time that is required for surfacing a submerged vehicle. Therefore, compressed air is favoured for the main deballasting because of the air’s capability of being stored at high pressures and displacing water in a fast manner once it is fed into the ballast tanks, thanks to it’s ability to expand as the submarine emerges and the surrounding water pressure drops. In addition, the compressed air systems must operate for at least a normal surfacing from periscopie depth, but also for surfacing from the maximum depth in the case of an emergency. From an engineering standpoint, ballast tank blowing systems are complex, but nevertheless are vital, for allowing the maneuvering of the submarine and it’s bouyancy within the water it navigates, regardless if it’s in a surfaced or submerged condition and must be done in the smoothest and with as little noise as possible. The requirements of designing and calculation of such systems are covered by the Class and Administration rules and regulations.

Design and Manufacture Ballast Management System Model for Reduce Ship Rolling Motion

The safety of maritime transportation is a critical aspect that must be addressed to ensure the well-being of ships and their crew. Frequent ship accidents highlight the need for improvements in the maritime transportation system. One of the causes of ship accidents is ship instability, leading to a loss of balance and even sinking. Ship stability is influenced by both internal and external factors, including human negligence in observing and addressing ship instability. This research aims to design and create a management ballast system model that can be operated automatically as a solution to reduce ship rolling motion. This system enables the ship to maintain balance using automatic side ballast tank management by utilizing two wing tanks on either side of the ship. The ballast management system will be equipped with an accurate ship roll angle detector, the Initial Measurement Unit sensor, a microcontroller, and a series of actuators, including relays as voltage control switches for the pump motor. This research involves simulation and testing/experiments at various angles, namely 5, 10, and 15 degrees. Simulations are conducted under conditions with and without the ballast management system, which is then confirmed through experiments under the same conditions. The expected outcome of this research is that the created ballast management system can be used to reduce ship rolling.

Automatic Water Ballast System Based on Arduino R3

In this modern era, technological development is very rapid, and many changes occur in technology, especially in human life, which also applies in the maritime field. Technology is very important to facilitate activities in human life so that everything that exists can be completed quickly, easily, and effectively. Of course, the development of this technology is very much the ability to carry out important infrastructure to improve the quality of work and time efficiency. Technology is also very useful in the business field because, with the development of technology, people will more easily get to know each other. This study aims to find out how the ballast filling system works and find out the components in the tool. The mode used is the Research & Development (R&D). Based on the findings and results of the study, it was concluded that the ballast system is a tool used to increase the ship's stability and increase the G force to be easily controlled at the equilibrium point of the fast or dismantled ship structure. The design of water ballast system operation aids is carried out sequentially in each manufacturing process and has been adjusted to the problem formulation. This teaching aid is very useful as a learning medium so that the material is easier to understand because it is demonstrated using real teaching aids.

An overview of the mechanical features of human occupied vehicles

Scientists are using human occupied vehicles to explore underwater environments. There are several mechanical features used in the design of human occupied vehicles. These mechanical features are primarily based on environmental factors such as high external pressure, low temperature, and corrosion resistance. In this paper, human occupied vehicles rated for 6,000 m depth are studied, including Alvin, Jiaolong, MIR-1/MIR-2, Nautile, and Shinkai 6500, as well as vehicles rated at 11,000 m depth, like Deep Sea Challenger, Fendouzhe, and Triton. As a review, this paper examines various mechanical systems in human occupied vehicles, such as the pressure hull, hatch, ballast system, trim system, exo-structure, and syntactic foam. Highlights Features of various human occupied vehicles up to 11,000 m of sea water Comparison of spherical pressure hull, hatch and viewports Various ballast systems adapted in different human occupied vehicle Size and shape of the pressure casings / enclosures Drop weight mechanism used in different human occupied vehicles

Theoretical foundations of freeing ships from heavy ice conditions

The topic of the study is to prevent damage to the ships hulls when sailing in polar waters in severe ice conditions, which is a dangerous situation that threatens environmental pollution and possible death of the vessel, its passengers and crew. It is noted that the intensive development of ice navigation in the development of the Arctic regions of the Russian Federation and other polar waters requires the development and improvement of methods for freeing ships trapped in heavy ice. Navigation of vessels in severe ice conditions is accompanied by significant difficulties and dangers for the vessel, its passengers and crew. This situation can be significantly aggravated if, at a certain stage of navigation in ice conditions, heavy ice begins to move, leading to compression of the ice channel in which the vessel is located. At the same time, the risk of the vessel hull destruction, the creation of water leakage and the possible death of the vessel, its passengers and crew increases, as well as environmental pollution occurs. The theoretical foundations of freeing a vessel from severe ice conditions, based on the principles of rocking and pushing, as well as cutting ice, clamping the vessel, which have proven their effectiveness in other fields of science and technology, are discussed in the paper. The use of the vessel theory apparatus and the experience of ice-breaking assistance make it possible to substantiate the possibility of effective application of methods of rocking, pushing and chopping ice to release ships caught in severe ice conditions. The theoretical possibility of using combinations of the operation of the ballast system, cargo booms and cranes, special actions of the crew trapped in the ice of the vessel, as well as its interaction with icebreakers and other vessels for cutting the clamping ice, rocking and pushing, increasing the efficiency of freeing the vessel from severe ice conditions, is shown. The materials of the paper can be used to develop practical recommendations for freeing ships from heavy ice conditions independently and using icebreakers and other vessels.

Radio-Controlled Submarine using a Water Bottle with an Integrated Camera

Abstract: We aim to make a wireless remote-control model of a submarine whose motion can be controlled from outside of the water with the help of a transmitter and receiver. Today, RC (radio-controlled) submarines can be used for underwater surveillance. The project is cost-optimized and uses readily available parts. The most important thing in an RC submarine is the control system and waterproofing of the electronic components. The key components of the control circuit are the ESC, radio control module, and propeller motor. Direction control uses servo motors to navigate the surface unit. The ballast tank is a PVC water bottle of cylindrical shape. Building a control system for the ballast system is a major challenge for this project. Circuits are sensitive and prone to interference. The submarine can be controlled with a remote control, and an onboard wireless camera can broadcast underwater scenes.

A combined control method of traction and ballast for an electric tractor in ploughing based on load transfer

Agricultural tractors are significant agricultural power machines that must be equipped with different implements according to tillage requirements and operate in a complex field environment. Aiming at the problem that the traditional traction control system could not balance the agronomic requirements of tillage and high-efficiency operation, this study proposed a combined control method of traction and ballast based on load transfer. This method was used for electric tractors with a battery position adjustment (BPA) structure. The tractor-implement system model was built to calculate the dynamic loads of front and rear axles accurately. Then, a multi-objective optimization function for traction performance was constructed, and the multi-objective particle swarm algorithm was employed to solve the optimal battery pack target position. The tractor controller real-time measured the draught force and battery position data. Based on the combined control strategy, the battery pack position and the tillage depth were adjusted to accomplish the cooperative control of the active ballast system and the electro-hydraulic hitch system. Finally, a field test platform for the electric tractor was developed. Ploughing tests under the traction control method and combined control method were performed. The test results showed that the tillage depth uniformity and traction performance under the combined control method were superior to the traction control method. In particular, compared with the traction control method, the tillage depth fluctuation range in the combined control method was reduced by 30.6%, the wheel slip was decreased by 15.1%, the traction efficiency was enhanced by 3.7% and the total motor energy loss was decreased by 4.9%. This study provides a technical reference for improving the economy of energy consumption and the uniformity of tillage depth of tractors in ploughing.

Design study of offshore floating wind and photovoltaic power generation platform

The oceans contain a huge amount of clean energy, of which wind and solar are the largest reserves and the easiest to access. In consideration of the many factors affecting traditional offshore semi-submersible platforms, the design of an offshore semi-submersible platform that can overcome the harsh marine environment and work efficiently is based on overcoming the many problems of low stability, low efficiency, and poor economy of existing semi-submersible platforms. The text, therefore, builds on previous designs to design an offshore floating platform that combines a floating wind turbine with photovoltaic power generation. Firstly, the paper combines various design concepts, proposes a model concept for the floating platform and the corresponding structural dimensions, designs the ballast system, and selects the materials for each part. The paper concludes with a simple calculation of the stability, loads, and cost of the structure. The overall high initial stability (GM) of the structure is greater than zero, the wind and wave loads are estimated to be 350,000 N and 50 million N respectively, and the cost is about 58,500,000 RMB per kW. The research offers a new approach to the future development of new green energy sources in the ocean and has implications for the design of new integrated concepts for floating platforms. The paper concludes by looking forward to the design of a more stable, economical, and efficient offshore floating power platform that will provide a new way of maximizing the exploitation of offshore energy for human society.

Dynamic characteristics evaluation of balance valve for seawater hydraulic variable ballast system considering the depth variation

ABSTRACT A seawater hydraulic variable ballast system (SHVBS) is used to dynamically adjust the weight of the submersible. The balance valve is a crucial component of SHVBS which has two working conditions called charging and discharging process. In this paper, an experiment simulating the ocean is built to obtain the dynamic characteristics of the balance valve, including the starting pressure and the pressure difference. Then there are analyzed by a kinematic model. The results show that as the depth increases, the pressure difference increases during charging process, while it remains unchanged during discharging process. Charging process is much worse than discharging process for balance valve. When the depth is 600 metres, the pressure difference during charging process is 45 times higher than during discharging process. Furthermore, friction force is the main factor that affects the starting pressure, while the hydraulic force mainly affects the pressure difference.

A novel fault diagnosis scheme for a ballast system

The Back Propagation (BP) neural network model is one of the neural network models suitable for model recognition and classification. However, a single BP network model cannot fully tap the feature information hiding in the data and is vulnerable to the uncertainty associated with system parameter changes and also suffers from the effects of long diagnosis times, inaccurate and undesired diagnosis results in applying a large amount of high-dimensional feature data. In addition, the standard BP algorithm has limitations in pattern recognition and classification. For example, it adopts the quadratic cost function to train the neural network, which can lead to low convergence accuracy, low convergence rate, and so on. Compared with the quadratic cost function, the cross-entropy cost function can effectively improve the convergence accuracy and the convergence rate of the neural network. The Dempster–Shafer (D–S) evidence theory is a powerful tool for handling incomplete, imprecise, and uncertain information and merging it when it derives from multiple BP networks. In order to overcome the drawbacks of a single BP network, it is necessary to divide the high-dimensional feature data into several different categories of low-dimensional feature data and to input the same dimensional feature data into the same BP network model, as well as to design the information fusion algorithms based on D–S evidence theory and multiple improved BP networks with the cross-entropy cost function. For this reason, this paper proposes a novel information fusion diagnosis approach based on D–S evidence theory and multiple improved BP networks for fault diagnosis and classification of multiple devices in a ballast system subjected to extreme environmental conditions. The proposed diagnosis approach utilizes multiple neural networks to carry out local fault diagnosis, adopts the D–S evidence theory to fuse the results of local diagnosis and derive the decision results, and introduces an improved BP algorithm based on the cross-entropy cost function into the individual neural networks to enhance the convergence rate and diagnosis accuracy of the individual neural networks. This method can overcome the deficiencies of individual BP networks in multiple BP networks in their poor diagnostic ability to handle incomplete, imprecise, and uncertain sample information. According to the design idea of the proposed diagnosis approach, a new fusion modeling for fault diagnosis of multiple devices is constructed for a ballast system. The validity of the proposed diagnosis method and model is illustrated through both simulation studies and experimental tests.