Fast Ferries Research Articles

NEURO-FUZZY SYSTEM TO CONTROL THE FAST FERRY VERTICAL ACCELERATION

This paper shows the design of a neuro-fuzzy system to control the vertical motion of a TF-120 fast ferry, so that to improve the passengers comfort by reducing the main cause of seasickness. The aim of this controller is to decrease the pitch acceleration by controlling the position of some actuators, varying their working angles. The controller is based on a fuzzy model of the ship behaviour. It has been simulation tested in regular and irregular waves with satisfactory results. The MSI (Motion Sickness Incidence), has been evaluated to prove the efficiency of this strategy. Although neuro-fuzzy controllers have been widely used before, the application of this strategy to control marine systems is novel.

NEURO-FUZZY MODELLING OF A FAST FERRY VERTICAL MOTION

A neuro-fuzzy system has been developed to model the behaviour of a fast ferry. The sources of the available knowledge are the physical laws of the vertical dynamics of the craft, and some experimental and simulated data of the ship performance in regular waves. The non-linear model has been obtained by applying adaptive neurofuzzy inference. It is focus on the vertical motion of the craft, both heave and pitch. The modelling problem is complex and the results are original, and have been proved satisfactory for regular waves.

MULTIOBJECTIVE CONTROL OF FLAPS AND T-FOIL IN HIGH-SPEED SHIPS

Fast sea transportation of passengers must considered safety and comfort requirements. Due to waves, there are heaving and pitching motions. These motions originate sea-sickness and can have negative effects on the ship. By means of submerged actuators, vertical motions can be smoothed. This paper considers the real case of a fast ferry with a T-foil and flaps. This is a control problem that also has to consider cavitation and possible fatigue of the actuators' system. In consequence there is a multiobjective optimization problem, controlling a non-linear system. A Multiobjective Genetic Algorithm is designed and applied to the case. The research obtains satisfactory results.

Hydrofoil singing on fast ferries

Hydrofoil singing phenomenon is sometimes observed on new and repaired fast ferries with hydrofoil systems. Hydrofoil singing is a tonal sound caused by interaction of the foil trailing edge with incoming flow. The intensity of the excited tone often dominates the total noise. Hydrofoil singing has very negative effects: first, the noise level is unacceptable for passenger transportation; second, vibration of the foil structure participating in singing leads to fatigue of the system and crack formation on foils and struts. The problem of hydrofoil singing first emerged on ferries with steel foils, but especially critically it was manifested on hydrofoil systems made from titanium. Experimental results obtained on a recent sea-going hydrofoil vessel are reported. Based on the structural peculiarities of the foil system, vortex shedding process and vibration of the trailing edge are discussed, and a lift-oscillator model is used for mathematical modeling. A new method of the special trailing edge profiling is considered; it allows elimination of the tone without degrading the hydrodynamic characteristics of the high performance vehicles.

Collision Regulations and Fast Craft

I wrote a paper for this Journal called Fast Craft and Collision Regulations two years ago that was an attempt to highlight weaknesses in the current Colregs that had become apparent through the advent of large fast craft, mainly fast ferries. The paper offered possible amendments to the Colregs in order to correct the situation and bring some order to this increasingly complex situation. The matter of amendments to the Colregs was discussed at length right up to IMO sub-committee level, but amendment of the current Colregs was rejected largely because of the diversity of opinion about this subject. Without a consensus, it is difficult to effect change and with hindsight the proposals presented in my paper were too complex, and perhaps too far reaching. The purpose of this second paper is to propose a much simpler solution, one which takes into account current practice and which does not close the door to more defined action in the future.

A Research on Motion Smoothing of Fast Ferries

This paper is about a research on the use of active appendages to smooth the motions of fast ferries. According to BAZAN specifications, the research focused on a fast ferry with a T-foil and transom flaps. A collaboration of three research groups, with the experimental support of CEHIP AR was established to accomplish the objectives. The research was scheduled as two main steps. A first step of control-oriented modelling has successfully been achieved. The second step is dedicated to control design and experimental evaluation, seeking for the best solution. First experimental results confirm good expectations with the use of the active controlled appendages. This paper describes the main aspects of the research: the problem to be solved, the methodology and fulfilment of the research project, and the most relevant results obtained.

A Simulation Tool for a Fast Ferry Control Design

The research considers a fast ferry with active appendages (actuators): a T-foil near the bow and transom flaps. The objective is to attenuate the ship's vertical motions. There is a problem of control design, to move the actuators in the most effective way. For an easy and safe control study, a simulation tool has been developed using MATLAB and SIMULINK: a modular architecture results where it is easy to integrate control strategies to be analysed. Simulated experiments can be run with the tool, to see the behaviour of the important variables: vertical motions of the ship, motions of the actuators, sea-sickness incidence, etc. The paper describes the simulation tool from a functional point of view, and explains some details of the main parts of its internal structure.

Control Code Generator Used for Control Experiments in Ship Scale Model

After a study of control design to get a good candidate for testing, it comes a step of experimental confirmation. The general objective of the research is to smooth the vertical motions of a fast ferry. A T-foil and transom flaps are added to a scaled down replica of the fast ferry. These appendages can move under control. So there is a control system installed on the replica, that moves the appendages using motors, and measures the main variables of the ship and actuators motions. This control system is based on an industrial PC with electronic interfaces for motors and sensors. The control algorithm obtained by the design, must be implemented as real-time control software, to be executed on the industrial PC. For a fast and easy translation from design to real-time application, a new software tool has been developed. This tool generates directly C++ code, easy to compile, from a graphical description of the control. With this tool, the experiments have been achieved in short time. During experiments, several non expected circumstances appear, but this was not a problem: the tool allows for an easy improvement of the original design. The paper describes the tool and its use during experiments.

Experimental Study of Controlled Flaps and T-Foil for Comfort Improvement of a Fast Ferry

Fast ships can suffer important negative effects from vertical accelerations. The sea-sickness of passengers is related, in a cumulative form, to these accelerations. Our research deals with the alleviation of vertical accelerations, using appendages that can move under control to counteract each incident wave: a T-foil near the bow and transom flaps. After a long modelling work, involving experiments in a towing tank institution, the conditions for the study of control design have been established. First experimental confirmations of the efficacy of controlled appendages have been achieved. A well tuned P.D. has been tested, with very promising results. The paper begins with a short recapitulation of the previous research. Next, the paper focus on the experiments with a replica with appendages.

Fast Ferry Safety Analysis for San Francisco Bay: Needs Assessment and Preliminary Framework

Fast ferry traffic and vessel speed are on the rise in San Francisco Bay. A conservative analysis estimates that daily fast ferry trips may increase from today’s 100-plus trips to 665 trips in only 10 years. Although providing great opportunities for industry and travelers alike, increasing speed and congestion raise important safety considerations that could overwhelm the existing safety infrastructure. The U.S. Coast Guard, California Maritime Academy, and Pacific Transit Management Corporation have developed the outline for a formal safety assessment (FSA) that will consider the effect of more fast ferries on San Francisco Bay from a port-waterway systems perspective rather than from the traditional vessel safety approach. The FSA process will detail existing project risks and forecast future risks, identify best practices, and recommend the implementation of the most effective, efficient, and equitable risk management alternatives. Safety issues raised by increasing fast ferry traffic are discussed, FSA aspects are detailed, and the most recent information on progress toward understanding and improving fast and safe ferry operations in San Francisco Bay is presented.

Freight Ferries in New York–New Jersey Harbor: How to Make Them Happen

The potential for freight ferries in New York–New Jersey harbor is examined. Freight ferries are defined as fast ferries transporting high-value, time-sensitive cargo, particularly air cargo, but also courier packages and even premium passengers. The proposal by a private entity for freight ferries is consistent with the trends toward increased use of fast ferries nationally, and the incipient use of these ferries at several worldwide locations. In the greater New York–New Jersey metropolitan area, freight ferries offer several opportunities. These ferries help to remedy the ongoing problem of congestion in the New York–New Jersey metropolitan area, particularly on roads and at crossings associated with air cargo surface delivery. Air cargo brings high economic value to the region, but the congestion problem must be resolved to maintain that contribution. Freight ferries create synergies with other freight and passenger delivery services. These ferries can also spur redevelopment of waterfront communities, particularly those waterfront locations isolated from the rest of the metropolitan area. However, implementing freight ferries has its obstacles. The major hurdle is finding appropriate landing sites, which is difficult because of competing uses, failure to plan for landing sites, and labor considerations. Safety and air quality issues also need to be addressed. Elements of a bold plan to make freight ferries happen in the New York–New Jersey metropolitan region are suggested.

Fast Ferry Vertical Accelerations Reduction with Active Flaps and T-Foil

The research deals with the design and use of actuators to improve the seakeeping performances of a fast ferry. The interest of the research is now restricted to heaving and pitching motions, with heading sea. The ship has active control surfaces (flaps and T-foil). The paper presents a control-oriented model of these actuators, in SIMULINK. This model can be easily coupled with a SIMULINK model of the ship, furnishing a simulation environment for control studies. Using this facility, a study of control alternatives (moving the actuators) has been started. We include in the paper first results with conventional PID control, which are useful as reference for comparison purposes.

Fast passenger ferries and their future

This papers examines the different choices of High Speed Craft (HSC) hull design available and briefly looks at the advantages and disadvantages of each hull form. The trends in various design aspects of HSC such as speed, capacity and size are studied. An investigation on the HSC development is conducted and the future of HSC in the UK is studied. A study onboard an HSC with the aim of trying to determine what passengers think of HSC and why they travel by them is also conducted. Finally, an analysis of the possible market for HSC is carried out.

Effects of Enhanced Ferry Service on Golden Gate Corridor Transportation: From Dromedary to Camel: How MV Del Norte Inverted the Ferry Ridership Curve

Golden Gate Ferry commuters consider speed as the paramount issue in ferry service. Since the Golden Gate Ferry’s introduction in September 1998, ferry patrons have consistently chosen to ride the fleet’s sole high-speed catamaran, MV Del Norte, even though survey respondents have said that this ferry is less comfortable than others. The unprecedented popularity of the new service, coupled with commuter unwillingness to use ferry feeders, has resulted in the terminal’s parking lot being overburdened. This parking problem initially resulted in lower midday ridership and indirect negative effects on the system’s overall efficiency. The addition of the catamaran to its passenger ferry fleet enabled Golden Gate Ferry to increase Larkspur-to-San Francisco service from 26 to 40 weekday trips. Operating at 35 knots, this vessel reduced transbay crossing time from 45 to 30 minutes. The enhanced service attracted new riders and dramatically changed peak period ridership times, inverting the ridership curve. However, the catamaran carries 325 passengers, about one-half of the other ferries’ capacities. This limitation has resulted in unmet demand on certain commuting trips and overflow of the ferry parking facilities as passengers arrive early to board the fast boat. Golden Gate Ferry has identified two possible means of encouraging the use of ferry feeder services and decreasing the demand for the limited parking capacity: guaranteed boarding for ferry feeder patrons and enhancement of the feeder services. These first steps are crucial to smooth ferry service operations as Golden Gate Ferry prepares for the arrival of its next fast ferry in 2001.

Applied physical geography in New Zealand

Physical geographers in New Zealand have a tradition of applied research in a variety of contexts, including environmental management as well as soil, vegetation and landform systems conservation. In recent years this work has been given new impetus (with the promise of even greater involvement) as a result of economic restructuring at the national level, restructuring of government departments and agencies dealing with environmental and resource management and conservation, the introduction of new statutes relating to environmental and resource management, and major changes in the funding and management of science research in the public sector. This article provides an overview of the institutional environment within which New Zealand physical geographers now carry out applied work. The contemporary resource management and legislative contexts are described and structural changes that have taken place in New Zealand science over the last decade are reviewed. Research undertaken by the authors or their research students provides examples of the different types of work now being undertaken by physical geographers in New Zealand under the new legislative and funding regimes. Two examples are described in detail. The first is drawn from research dealing with catchment hydrology and water supply and has been undertaken by a physical geographer employed by Landcare Research, a Crown-owned research company. The second comes from work carried out by two university-based physical geographers into the environmental effects on coasts of a new mode of marine passenger transport (`fast ferries'), to meet the requirements of new environmental legislation.

A Summary of the IMO High-Speed Craft (HSC) Code and Its Impact on the First U.S. Vessel Built to This Standard

SASSACUS is a 45-meter FBM TRICAT fast ferry built at Pequot River Shipworks in New London, Connecticut. This paper summarizes how SASSACUS set a precedent by being the first U.S. vessel built entirely to the International Maritime Organization's new International Code of Safety for High-Speed Craft (HSC Code). The background and philosophy of the HSC Code are discussed, as well as how the classification society Det Norske Veritas and the regulatory agency U.S. Coast Guard have affected the outcome. Specific difficulties experienced in the construction and trials of SASSACUS are mentioned. The impact of this project on future ships constructed to this code is summarized

Fast Craft and the COLREGS

The past 10 years have seen an explosion in the use of high speed marine craft. This explosion has been in most sectors of operation, leisure, passenger carrying and military, and is now poised to expand into the cargo carrying sector. The sizes of the new generation of fast craft can range from small 60 knot, 7 metre leisure craft up to fast ferries which are 140 metres long with speeds of 40 knots. Future developments encompass 40 knot large cargo ships, 100 knot passenger and cargo vessels and very high speed military craft. Added to this galaxy of high speed concepts is the 200 knot wing-in-ground (WIG) craft, which, because it flies close to the sea surface, will interact with other marine traffic.

Collision Risk with Fast Ferries

Collision Risk with Fast Ferries

The development of a ride control system for fast ferries

In the expanding market for fast ferries there is a growing requirement for the use of Ride Control Systems (RCS) to give enhanced passenger comfort and reduced crew fatigue. Such a system, the “Ocean Leveller”, has been developed by AMECRC for Austal Ships Pty Ltd. and this has been used in 40 m catamarans and monohulls. Dynamic simulation played an important role in the development of the RCS and it continues to be used, as the application of the system is extended to both larger vessels and others of different configuration. This paper describes the development of the control system, demonstrates the role of simulation, outlines its development and illustrates how the verified model can be utilised.

超細長双胴船型による高速フェリー

Ishikawajima-Harima Heavy Industries Co Ltd (IHI) and the University of Tokyo recently developed a fast ferry by applying the concept of super-slender twin hull (SSTH). Low wave-making resistance by a super-slender hull form contributes to good fuel economy. Good seaworthiness by a super-slender hull form and a specially designed bow shape have also been confirmed by means of a series of model tests. Principal features of a prototype design are as follows: length between perpendicular = 75m, breadth (moulded) = 19.4m, draught (moulded) = 2.3m, four sets of 6000 ps high-speed diesel as main engine. Both propeller and water jet are used as propulsion system. The hull structure is made of aluminium alloy. A small version of the SSTH ferry was scheduled to be launched in August 1991, and its advantages will be verified in the open sea.