A building cost estimation method for inland ships

There is very little publicly available data about the building cost of inland ships, especially for ships that have dimensions that differ significantly from those of common ships. Also, no methods to determine the building cost of inland ships are described in literature. In this paper, a method to estimate the building cost of inland ships is presented. Furthermore, the method is used to develop rules of thumb for the cost of inland ships as a function of their length, beam and draught. All material that is presented in this paper is based on or taken from Hekkenberg [2013].Marine and Transport TechnologyMechanical, Maritime and Materials Engineerin

Inland Ships for Efficient Transport Chains

The European inland waterway transport sector is a highly competitive one. The transport operators in this sector are mainly small companies with only one ship. Such companies have very few possibilities to distinguish themselves from their competitors. At the same time their main asset, their ship, is often highly standardized. In this thesis, it is researched to which extent the small companies in the inland waterway transport sector can improve their competitive position. This is done by minimization of the required ship rate and total logistical cost through optimization of the main dimensions of inland ships. To achieve this aim, a ship design model is developed. This model is used to create large series of designs in which length, beam and draught are varied systematically. These designs are used to develop a set of rules of thumb for steel weight, lightweight, building cost and cargo carrying capacity of inland ships with any combination of length, beam and draught. The optimal dimensions of a ship are a function of the properties of the transport chain in which it operates and the waterway on which it sails. Therefore, a second model is developed that allows assessment of the required ship rate and total logistical cost as a function of the main dimensions of the ship and the most important properties of the transport chain and the waterway. Finally, through an extensive scenario analysis flow charts are developed that allow estimation of the optimal ship dimensions as a function of the properties of the transport chain, the cargo type and the water depth.Marine & Transport TechnologyMechanical, Maritime and Materials Engineerin

3D RANS simulations of shallow water effects on rudder hydrodynamic characteristics

An accurate estimation of the rudder forces and moments is essential for manoeuvrability prediction. Previous research has shown that ships have different manoeuvring performance in deep and shallow water. Before considering the rudder’s contribution to shallow water manoeuvring, it is meaningful to analyse the shallow water effects on the rudder itself. In shallow water, the rudder gets close to the channel bottom. Therefore, mirror effects are expected, which may greatly affect the rudder effective aspect ratio and the generated rudder forces. Instead of high-cost model tests and time consuming full ship CFD simulations, this paper applies 3D RANS methods to analyse the shallow water effects on rudder hydrodynamic characteristics. 3D RANS simulations are carried out with a pressure-based coupled algorithm through ANSYS Fluent 16.2. The turbulence is simulated by a realisable k-e turbulence model. Based on a NACA 0020 profile, the method is validated through a comparison of the CFD results with the wind tunnel tests. Then, NACA 0020 spade rudders with geometric aspect ratios of 1.2 and 1.5 are tested with different tip clearance. Rudder lift and drag coefficients are generated to calculate the normal force coefficient for manoeuvring simulations. Finally, shallow water effects on rudder hydrodynamics are summarised.Ship Design, Production and Operation

Hydrodynamic Characteristics of Twin-Rudders at Small Attack Angles

RANS simulations are implemented to analyse the hydrodynamic characteristics of twin-rudders, i.e. Flat plate rudders, NACA rudders, and Wedge-tail rudders. The study mainly focuses on small attack angles. Results show that the NACA series is the most efficient profile while the Wedge-tail rudder has the highest rudder effectiveness.Marine and Transport TechnologyMechanical, Maritime and Materials Engineerin

Sixty years of research on ship rudders: Effects of design choices on rudder performance

Rudders are primary steering devices for merchant ships. The main purpose of using rudders is to generate forces for course keeping and manoeuvring. In exceptional cases, rudders are also used for emergency stopping and roll stabilisation. Furthermore, rudders affect propeller thrust efficiency and total ship resistance. Therefore, rudders are important to navigation safety and transport efficiency. The performance of rudders depends on the rudder hydrodynamic characteristics, which are affected by the design choices. Scholarly articles concerning the design of rudders date back more than 60 years. Moreover, a lot of knowledge fragments of rudders exist in literature where ship manoeuvrability and fuel consumption are discussed. It is worthwhile to gather this information not only for researchers to advance the state-of-the-art development but also for designers to make proper choices. To have a contemporary vision of the rudders, this paper presents a consolidated review of design impacts on rudder performance in ship manoeuvrability, fuel consumption, and cavitation. The discussed design choices are rudder working conditions (Reynolds numbers and angles of attack), profiles (sectional shapes), properties (area, thickness, span, chord, and rudder aspect ratios), types (the position of the stock and the structural rudder–hull connection), and interactions (among the hull, the propeller, and the rudder). Further research is suggested on high-lift rudder profiles, multiple-rudder configurations and interactions among the hull, the propeller, and the rudder. Recommendations for industry practices in the selection of the rudder design choices are also given.Accepted Author ManuscriptShip Design, Production and Operation

The influence of shallow water and hull form variations on inland ship resistance

Effects of a hull form variation and shallow water on a 110-meter inland ship are presented as preliminary results of the Top Ships project, which is initiated in order to improve inland ship design tools and design guidelines.Marine and Transport TechnologyMechanical, Maritime and Materials Engineerin

Identification of a task-based implementation path for unmanned autonomous ships

Autonomous and unmanned shipping are currently hot topics in the maritime industry. However, there are many different views on how the ultimate goal of an unmanned, autonomous ship will be reached. On any given ship, a large range of tasks is performed every day, each of which need to be replaced in such a way that no human presence is required on board. In this article, different possible combinations of tasks to be replaced are explored systematically, leading to an overview of the most beneficial combinations of tasks to replace together and a logical sequence in which to replace them. This leads to a plausible implementation path from low-manned ships towards fully unmanned autonomous ships.Ship Design, Production and Operation

The effect of autonomous systems on the crew size of ships–a case study

Recently, autonomous ships have gotten a lot more attention both in the media and in research. However, very little research has focussed on the effects of automation on the size of the crew. This paper analyses the effects of added automation on the required size and composition of the crew on a 750 TEU short sea container vessel. A Crew Analysis Algorithm is used to determine the cheapest crew composition to perform the tasks required to operate a ship. Using this algorithm, two potential automation options are investigated: automating the navigation tasks and automating the mooring tasks. Automating the navigation tasks decreases the required crew size in the normal sailing and arrival & departure phases by 3 and 1 crew members, respectively. The loading & unloading phase is unaffected. Automating the mooring tasks reduces the required crew in the arrival & departure phase to 2. It is concluded that since individual automation options do not affect the crew requirements for all travel phases, their effect on crew reduction is limited unless several options are combined. However, with a change in task assignment and different training of crew members, a reduction of the required number of crew members is possible.Ship Design, Production and Operation

Waterborne platooning in the short sea shipping sector

The potential to implement the concept of waterborne platooning in the European short sea transportation system is currently being explored. In the concept, a platoon is referred to as a “Vessel Train” (VT). A VT is composed of a fully manned lead vessel and a number of follower vessels. The lead vessel takes over the navigational and situational awareness responsibilities for the follower vessels (FVs). This enables automation of the navigational tasks on these follower vessels, which in turn leads to a potential reduction in crew size and associated cost. This paper describes the economic viability of the VT concept. It is applied to a short sea case study in which a fully matured system and an early implementation stage are mimicked. The assessment shows that viability is strongly influenced by the number of crew members removed from the FVs and the departure intervals of consecutive trains. It concludes that while economically viable cases can indeed be identified, the benefits created by this VT implementation are present but not very large. This is making it questionable if a successful application of the concept can be achieved given the risk and uncertainty surrounding the individual parameters.Ship Design, Production and Operation

Retrofit solutions for inland ships: The MoVe IT! approach

In MoVe IT!, a project in the European 7th framework package, it is investigated how existing European inland cargo ships can be retrofitted in order to improve their economic and environmental performance. In the project, experts from academia worked closely together with five ship owners to identify the most promising retrofit options for one of their ships and to elaborate them. In this paper, the MoVe IT! approach is discussed, as well as some key results. After a brief introduction to the project, an overview of all identified retrofit options is presented, followed by the selection of the options that were deemed most desirable. As an example of the MoVe IT! solutions, the elaborated hydrodynamic retrofit options for the coupled unit MS Herso I and barge Leonie are discussed in detail, followed by a short overview of the results of retrofit attempts for all ships surveyed within MoVe IT!. The paper is concluded with the most important lessons that were learned from the efforts to find good retrofit solutions for inland ships.Marine and Transport TechnologyMechanical, Maritime and Materials Engineerin