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Исследована маршрутная форма организации работы баржебуксирных судов со сквозной формой работы тяги и сменной формой согласования работы тяги и тоннажа в конечных пунктах. Определена необходимость учета соответствия линейных и технических характеристик судов условиям предстоящего рейса. Разработанная методика позволяет при помощи имитационной модели выполнить предварительный отбор судов для работы на линии. [ABSTRACT FROM AUTHOR]

The synthetic fiber ropes are commonly employed as the main material for the towing line to connect the towed ship and tug boat. The diversity of material e.g. polyester, aramid, and HMPE could impact the behavior of towing system and lead the instability of towed ship. Following the practical method previously proposed for the towing system analysis, authors aim to present a numerical model to properly take into account the characteristics of fiber ropes into the towing system. Specially, the dynamic stiffness of fiber ropes which is determined according to the mean load of the towing line is considered when solving the governing equations in the time domain. A detailed iteration procedure for the calculation of dynamic stiffness is described. The performance of dynamic yaw and lateral offset of towed ship under various wind speeds are discussed. The effect of various types of fiber ropes for the towing line and the initial length is also investigated thoroughly. Results of case study show that diverse material characteristics could influence the ship's directional stability significantly. The shorter towing line and stronger wind can reduce the fishtailing effect of the towed ship while the longer towing line would make the motion period larger. • Three types of synthetic fiber ropes are studied in the towing operation. • The dynamic stiffness considering mean load is employed in the numerical model. • Dynamic towing analyses are performed to study the ship behavior under wind loads. • The impacts of material diversity, towing line length, dynamic stiffness and wind speed are discussed. [ABSTRACT FROM AUTHOR]

The use of “Standard Maneuvering Orders” for tugboats, vocabulary and phrases mutually pre-agreed between ships and tugboats, is essential for the former to provide clear direction for the latter when berthing or un-berthing safely. Tugboats will need time to change their posture before they take actions in response to orders from persons responsible for ships’ maneuvering. Therefore, when giving directions to change tugboats’ posture, persons who handle their ships are required to send out tug orders, with regard to “delay time,” a gap be-tween the orders from ships and the actions taken by tugboats. “Tug Orders” standardized and used in Japan are composed of the following three factors concerning towage work: tugboat’s motion, direction and engine power, but the author’s research shows that there are “Non-standard” special maneuvering orders other than those “standardized,” which causes such problems as a gap in perception between pilots and tugboat’s opera-tors, etc. The purpose of this paper is to research the delay time between orders for and actions by tugboats and consider the appropriate and safe timing of providing instructions to them, and then to propose globally-authorized “Standard Maneuvering Orders for tugboats”, discussing a problem involved in the use of the special orders used in Japan, and the way in which tug orders are used in other countries.

About the "Elbe" arbitration, however, the arbitrator's decisions were one-sidedly to the advantage of the Czechoslovak Government which planned to establish a state-owned Elbe shipping industry. Die Abtretungen deutscher Schleppdampfer und Kähne an die Tschechoslowakei - Zur 100sten Wiederkehr des Jahrestages des "Elbe"-Schiedsspruchs von Paris vom 14. The arbitrator's latter requirements were perfectly suited to the needs of the Czechoslovak government which planned to establish a State Elbe shipping company out of the entire fleet of vessels to be ceded by Germany. [Extracted from the article]

With the increasing deep water oil & gas exploration, there is also an increase of the demand for offshore operations involving multi-vessels. Such operations require high level planning and coordination, which in most cases occurs by information exchange at the operation level, being each vessel commanded independently. Examples of such operations are offloading, subsea equipment installation and research operation, always involving multiples dynamic positioned (DP) vessels. The advantage of the cooperative control arises with the reduction of the relative positioning error during station keeping or transient maneuvers. In this work, consensus control concepts are applied combined with the DP System of each ship. The cooperative DP controller will be investigated with the analysis of the coupled dynamics of the vessels. The influence of cooperative control gains on the whole system will be discussed, using the frequency response of the open loop system. Fully nonlinear time-domain simulations and experimental results will be used to demonstrate the operation of cooperative control. Besides that, comparisons between the small-scale experiments and equivalent numerical simulations will be carried out, validating the numerical's results. The adopted design requirements are also demonstrated to be met. [ABSTRACT FROM AUTHOR]

The article offers information on the history of BMK-70 tugboats which was used by Red Army of Poland beofre 1947. Various topics discussed include preservation of its equipments in Polish museums, its exhibition during the military expositions, how it supports in learning about history of military engineering equipment and collection of army's pre-war equipment. It further discusses other armaments with which army was equipped and construction of these tugboats at the Rybinsky Kutrow Construction Plant in Poland.

In this paper, we study a barge and tugboat joint scheduling problem arising from a river–sea intermodal transport system, where non-self-propelled barges travel with the help of tugboats between an inland river bulk port and sea transshipment platforms to transport cargo. Due to limited channels and the sequential scheduling among ships, transit inefficiency and resource under-utilization often occur, thus it is essential to design barge timetables and tugboat paths. This paper jointly schedules barges and tugboats in a river–sea transshipment port with a tidally influenced channel, and focuses on barge round trips with multiple legs. We construct a state-space–time network from the perspective of tugboats, in which the state implies whether a barge is served by a tugboat. The problem is formulated as an integer programming model based on the network to minimize time taken for bulk cargo transshipment. A tailored variable neighborhood search algorithm is designed and its efficiency, effectiveness, and stability are demonstrated by numerical experiments, which are based on real data from the Boffa port. It is demonstrated that, by joint scheduling barges and tugboats, transfer efficiency can be significantly improved under limited tugboat resources and shorter tidal windows. The results also provide managerial insights on schedule and valuable conclusions about the resource allocation in the port. • Introduce an integrated barge-tugboat scheduling problem for river–sea transport. • Develop a state-space-time network and an integer programming model. • Design a variable neighborhood search algorithm. • Verify the performance of the proposed algorithm via computational experiments. [ABSTRACT FROM AUTHOR]

Amphibious tractors are capable of towing loads over land and water, which will save time effectively and reduce the cost of transport between water and land. Due to their smaller displacement and more fragile stability, the hydrodynamic characteristics of amphibious tractors are quite different from those of tugboats. The towing position will significantly impact the attitude and resistance characteristics of the vehicle. In this paper, the towing position of a light amphibious tractor is thoroughly investigated, in order to improve hydrodynamic characteristics and reduce energy consumption of vehicles. First of all, the towing force effect is researched based on the force equilibrium model. Secondly, a numerical model is established referring to the Reynolds Averaged Navier-Stokes method, which is validated by towing experiments. Moreover, various towing position forms are evaluated to research the towing effects and working principles. Eventually, a coupled model of pitch and heave motion is established to investigate the dynamic response in the longitudinal plane. Results indicate that towing positions at the rear of the vehicle, combined with low height, are conducive to the hydrodynamic performance of amphibious tractors. • The hydrodynamic characteristic of an amphibious tractor is investigated. • The effects of longitudinal and vertical towing positions are studied. • Towing force position significantly affects the resistance, trim, and stability. • Lowing the towing position can improve the trim and resistance characteristics. • Setting the towing force at the rear can improve the initial stability and seakeeping. [ABSTRACT FROM AUTHOR]

This paper presents a methodology for determining the components related to the heel of liquefied natural gas (LNG) carriers, excluding the heel of the vessel due to waves. The described method was applied to the description of under keel clearance of vessels approaching the outer port of Świnoujście. The method includes the determination of heel components caused by: draught reading errors, wind, current, tugboats and vessel maneuvers. Determination of the last component was carried out using a 2-stage method. In the first stage, simulation methods were used to identify the parameters of ship movement. In the second stage, the maximum heel of LNG carriers was calculated by analytical methods. [ABSTRACT FROM AUTHOR]

The maritime industry is in a mind-set to save fuel and reduce emissions. How one achieves this end, however, can be a matter of some debate. Although substantial industry effort is being placed on things that can be optimized, to achieve real benefit and financial return one must first understand the details about how the vessel consumes propulsive energy during its mission. This article discusses a rational, simple, and effective systems engineering approach to identify power and fuel demands via computational propulsion analysis of the individual operating modes of a vessel's duty cycle. It explains sensible consumption metrics that can be used to evaluate and compare different physical systems, strategic plans, or helm decisions. A duty cycle operating mode analysis calculation for a tugboat in multirole service (as a harbor tug and in long haul ocean barge towing) is demonstrated using commercial off-the-shelf software, including examples of design-side and shipboard decision options and consequences. [ABSTRACT FROM AUTHOR]

The article reports that shipping company Foss Maritime plans to develop its tugboat units to meet the demand of markets in m arine transportation services.

The article focuses on the trend of storage tank for liquefied natural gas (LNG) in diesel tugboats.

The article discusses the modification of the design and function of the anchor handling tug supply (AHTS) driven by various factors such as the evolution of the working requirement of deep water operators, technological innovation, and the need for cost efficiency.

The article discusses the emergence of shortcomings of the statics in the inclusion of dynamics due to ship motions such as the anchorage of a vessel and mooring a tug.

In this paper, the problem of accurate positioning of an unactuated surface vessel by using multiple uni-directional tugboats is investigated. Specifically a robust controller that ensures asymptotic position tracking is designed. The control design procedure is implemented in two steps: Initially by locating opposing tugboats to specific configurations, the overall problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Then via a matrix decomposition, a novel robust controller methodology is proposed. The stability of the overall system is ensured via rigorous stability analysis where asymptotic position tracking is ensured. Numerical simulation results are presented to demonstrate the efficiency of the proposed controller. [ABSTRACT FROM AUTHOR]