The growth of marine traffic in harbors, and the subsequent increase in vessel and propulsion system sizes, produces three linked problems at the harbor basin area: (i) higher erosion rates damaging docking structures; (ii) sedimentation areas reducing the total depth; (iii) resuspension of contaminated materials deposited at the seabed. The published literature demonstrates that there are no formulations for twin stern propellers to compute the maximum scouring depth. Another important limitation is the fact that the formulations proposed only use one type of maneuvering during the experimental campaign, assuming that vessels are constantly being undocked. Trying to reproduce the real arrival and departure maneuvers, 24 different tests were conducted at an experimental laboratory in a medium-scale water tank using a twin propeller model to estimate the consequences and the maximum scouring depth produced by stern propellers during the backward/docking and forward/undocking scenarios. Results confirm that the combination of backward and forward scenario differs substantially from the experiments performed so far in the literature using only an accumulative forward scenario, yielding deeper scouring holes at the harbor basin area. The results presented in this paper can be used as guidelines to estimate the effects of regular vessels at their particular docking location. reducing its operability for larger draft vessels and the area has to be dredged often enough for safe navigation (with sufficient keel clearance). Moreover, an environmental problem can also arise from the scouring effects of stern twin propellers of the vessels, and the increase in marine traffic in ports is also increasing the accumulation of heavy contaminants in some areas of the harbor. One of the engineering solutions to improve the water quality of the harbor is to trap the contaminated sediment below a layer of coarser gravel [2]. However, as reported by [3,4], the action of stern propellers over the seafloor can negate the solution and free the contaminated sediment creating an important issue that correlates sediment resuspension of contaminants due to the stern propellers' effects and water quality requirements of the cruise shipping industry.Therefore, the growth of marine traffic in harbors and its subsequent increase in vessel and propulsion system sizes produces three linked problems at the seabed of the harbor basins: (i) higher erosion rates damaging docking structures; (ii) sedimentation areas reducing the total depth of the harbor basin and its operability; and (iii) resuspension of contaminated materials deposited at the seabed.The formulation published and used so far to investigate the erosion rates of ship's propellers is based on empirical equations with a dependent variable named efflux velocity, V 0 . Efflux velocity is defined as the average velocity of the flux nearby a single propeller in a plane parallel to the propeller blades. The first empirical equation for V 0 was developed by [5,6], and detailed the expression ...

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This contribution investigates the economic benefits of using weather ship routing on Short Sea Shipping (SSS) activities. The investigation is supported with the development of a ship routing system based on pathfinding algorithms, the parametrization of the wave effect on navigation and using high-resolution meteo-oceanographic predictions. The optimal ship routing analysis is investigated in a European SSS system: the link between Spanish and Italian ports. The results show the economic benefits using ship routing in SSS during energetic wave episodes. The rate of costs savings may reach the 15% of the total costs under particular bad weather conditions in the navigation area. The work establishes the basis of further developments in optimal route applied in relatively short-distances and its systematic use in the SSS maritime industry.

In accordance with Part A, Chapter I, Section I/11 Revalidation of Certificates of the Standards of Training, Certification and Watchkeeping for Seafarers (STCW) 2010 Convention, continued evaluation of professional competence shall be established, among others, by successfully completing an approved training course or courses. Every master, officer and radio operator holding a certificate issued or recognised under any chapter of the convention other than chapter VI, who is serving at sea or intends to return to sea after a period ashore, shall be required, at intervals not exceeding 5 years, to demonstrate continued professional competence, in order to continue to qualify for seagoing service. The main objective of this research is to design a model course using simulation technology to train and demonstrate seafarers' competence in accordance with the provisions of STCW Code for existing seafarers who need to revalidate their professional maritime certificates also in accordance with the standards governing the use of simulators, Reg I/12 of 2010 STCW Code. The purpose of this revalidation simulation-based model course is to assist maritime training institutes and their teaching staff in organising and introducing specific training courses for revalidation of certificates of competence (CoCs) as well as enhancing, updating or supplementing existing training material where the quality and effectiveness of the training courses may thereby be improved. Only those STCW competences relating to

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The present contribution aims to implement a new methodology to prevent Roll on-Roll off vessels (RO-RO) from causing severe scouring actions. The methodology combines field, experimental, theoretical and numerical tools exchanging information to establish the manoeuvre potential scouring damage. The main contribution is the introduction of a manoeuvre ship simulator to obtain variables that otherwise cannot be obtained in field studies. These variables, all related to ship’s propeller behaviour, are the rotational speed, the pitch ratio and the engine power during the whole manoeuvre. Results show an over-prediction of the theoretical and experimental axial velocity and maximum erosion depth, indicating their clear limitations and the necessity of accurate data to apply the method. The methodology used with the key incorporation of the manoeuvre simulator is revealed to be a very useful tool to study new manoeuvres (including the possibility to work with a single or a couple of tugboats during the docking and undocking manoeuvres) to prevent propeller scouring actions.

According to the mid-term review of the EU White Paper on Transport, short sea shipping is expected to grow at a rate of 59% in metric tonnes, from 2000 to 2020. If we consider that the overall expected growth in freight exchanges is of some 50%, sea transport is one of the most feasible ways to reduce traffic congestion on European roads. High speed vessels are a possible way to compete with road transport on certain routes ; however, these ships are highly affected by heavy weather. This paper analyses the weather influence on several short sea shipping routes to be served by fast ships.K E Y W O R D S 1. Short sea shipping.2. Fast ships. 3. Significant wave height.

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