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Aquest treball presenta el procediment de validació d`un model 3d del vaixell `la voladora` de la classe globe 5.80. Es divideix en quatre capítols, cadascun detallant aspectes específics del procés. a la introducció es dona una visió general de la tipologia de vaixell de què tracta aquest treball, el class globe 580, a fi de situar el lector en el context de l’estudi. En aquesta secció també s’estableixen els objectius generals i els objectius específics del treball i es presenten els motius principals per a la realització del mateix, així com la seva rellevància en relació al procés constructiu de les embarcacions. el segon capítol descriu de manera detallada la metodologia utilitzada per recopilar dades de comportament del vaixell real i la informació necessària per a realitzar el model digital. En aquesta secció, també es descriuen les simulacions efectuades amb el model 3d per validar la seva precisió i realisme, comparant aquests resultats amb els obtinguts al treball de camp. el tercer capítol presenta els resultats detallats del treball de camp i les simulacions, mostrant-los gràficament i numèricament per tal d`avaluar l`eficàcia del model 3d en representar fidelment el comportament del vaixell a la realitat. finalment, en el quart capítol, es discuteixen les dades recopilades, oferint una conclusió exhaustiva sobre les discrepàncies entre el model i la realitat, i explicant detalladament les possibles desviacions que existeixen entre els resultats esperats i els obtinguts, així com les implicacions pràctiques i les oportunitats de millora per a treballs futurs.

Este trabajo de final de grado plasma los resultados y conclusiones derivados de tres pruebas de estabilidad (experiencia de estabilidad, prueba de balance o roll test y prueba pull down) llevadas a cabo en dos embarcaciones de la clase globe 5.80 ubicadas en el club marítim de barcelona. el manuscrito consta de seis capítulos. En el primer capítulo se hace una introducción al trabajo, en el segundo se explica el origen y las características de las embarcaciones de esta clase. En el tercer capítulo se describen cada una de las pruebas de estabilidad, desarrollando el propósito, la metodología y los materiales necesarios de cada prueba. En el cuarto capítulo se muestra el trabajo de campo realizado para obtener los datos de las tres pruebas de estabilidad de las embarcaciones. En el quinto capítulo se analizan y se discuten los resultados obtenidos. Finalmente, en el último capítulo se exponen las conclusiones del trabajo. para obtener la información necesaria para el desarrollo de este tfg, se han utilizado dos metodologías. Por un lado, la parte teórica se ha realizado a partir de la revisión de diferentes fuentes bibliográficas y páginas web. Por el otro lado, para la parte práctica, se ha realizado un trabajo de campo con la recopilación de datos en cada prueba en dos embarcaciones. gracias a los resultados obtenidos, se ha podido conocer mejor el comportamiento y la estabilidad (inicial y grande escoras) de las embarcaciones de esta clase.

For the investigation of the impact of the propeller slipstream on the port facilities, detailed analyses are carried out using a Reynolds-Averaged Navier-Stokes (RANS) method. The characteristics of the propeller flow field were studied, taking into account operating conditions during berthing and unberthing, interactions with the ship hull, quay wall and harbor bed. To obtain the necessary maneuvering data, information was extracted from the voyage data recorder (VDR) of a twin-screw RORO vessel during berthing and unberthing in the Port of Lubeck- ¨ Travemunde. Automatic identification system (AIS) and ¨ VDR data sets were collected and analyzed to identify conditions of interest for the numerical investigations. The vessel is equipped with two flap rudders and two bow thrusters. RANS simulations were performed for different rudder angles and number of revolutions of the main propellers (MPs) and transverse thrusters (TTs). The simulation results include unsteady velocity and pressure distributions in the flow field near the quay walls and harbor bed, considering different positions and orientations of the ship relative to the quay walls. The calculated maximum axial induced velocities are compared with those obtained using the semi-empirical formulae. In addition, the proper orthogonal decomposition (POD) on the harbor bed was used to evaluate the wall shear stress (WSS) and turbulent kinetic energy (TKE) to identify locations of maximum scour potential. The numerical results were thoroughly evaluated and analyzed to provide a robust basis for future extensions of the semi-empirical formulae.

The importance of the study of ship motion characteristics lies not in the motions themselves, but rather the effects caused by these dynamic motions. Motions are significantly influenced by a multitude of factors, including external disturbances such as waves or wind as well as vessel’s design and construction parameters. This work presents an initial analysis of the vessel motions based on the rotational movements roll, pitch and yaw. This motion monitoring will be done by using a do-it-yourself low-cost apparatus, designed and assembled at the University of Saint Andrews. It combines an Inertial Measurement Unit (IMU), with a GPS and an external battery to operate independent of the vessel. The results of motion monitoring trials are presented in this work, confirming that the low-cost IMU used are appropriate devices for vessel motion monitoring. This finding represents a significant advancement over the more artisanal methods utilized thus far, while also entailing a significant cost reduction compared to other inertial measurement devices with costs up to 20 times higher., Peer Reviewed

The present study aims at computing and analysing the eroded sediment volumes induced by twin-propeller jets near a vertical quay wall from the main geometric characteristics of the scour hole. Two different scouring mechanisms govern the scouring process: i) the down-flow due to the interaction between the propellers jet and the wall, and ii) the direct impact of the propellers jet flow on the seabed. For this reason, the whole study area is divided into two subzones: 1) ’near the wall’ field; 2) ’far from the wall’ field. Both forward and backward rotation of the propellers during manoeuvring are analysed. The results show that, for the two manoeuvring states, the relationship between the eroded volume and the geometric characteristics of the scour hole in the near-wall subzone does not change, meaning that the backward rotation does not affect the morphology of the scour hole near the wall. Moreover, the eroded volume can be determined as a function of the maximum depth near the wall and, with higher accuracy, as a product of the three main geometric characteristics of the scour hole at any time-stage during the scour hole development, Postprint (published version)

This manuscript presents an erosion induced by manoeuvring ships assessment methodology in harbour basins with low bed clearance conditions. From the evolution of the bottom morphology, obtained from bathymetric surveys performed by the Port Authority, AIS data is used to analyse the traffic patterns in the basin and to relate the particular ships manoeuvres with the bottom morphology evolution. This allows for the detection of ships causing higher erosion in the basin. The manoeuvre simulator yields the use of the engines and thrusters during the in-port manoeuvres. Afterwards, literature equations are used to perform a stability assessment of the bottom material allowing to compute the required size for a rock protection layer in the basin., Peer Reviewed

Este proyecto parte de la necesidad, como ingeniera naval, de facilitar el trabajo a la hora de diseñar un buque de recreo. Hasta ahora, para llevar a cabo esta tarea, era necesario realizar una búsqueda exhaustiva y laboriosa de buques con las mismas características que el buque a diseñar. Esta parte del proyecto es imprescindible para poder obtener un dimensionamiento preliminar del buque. el objetivo principal de este proyecto es encontrar unas ecuaciones que permitan obtener las dimensiones principales de un yate, partiendo de la eslora, sin necesidad de tener que realizar un estudio estadístico de yates similares. Para conseguirlo, el primer paso ha sido recoger datos de un total de 2676 yates existentes en una base de datos de alcance mundial. A continuación, se ha analizado esta base de datos para eliminar datos erróneos y filtrar los yates según categorías, para poder ajustar las ecuaciones finales a un tipo concreto de yates y a un rango específico de esloras. Una vez realizado este estudio estadístico se han obtenido unas relaciones de diseño preliminar exitosas para yates de más de 24 metros de eslora.

Este trabajo de fin de máster analiza los datos hidrodinámicos adquiridos durante la tercera campaña en el Archipiélago de las Perlas (República de Panamá). Dicha campaña ha estado apoyada por el Centro de Cooperación al Desarrollo (CCD) de la Universitat Politècnica de Catalunya (UPC), en colaboración con la Universidad Marítima Internacional de Panamá (UMIP). El proyecto pretende dar continuidad a los resultados obtenidos en dos proyectos CCD-UPC anteriores (2018-U013 y 2019-B011).

Ships maneuvering in low bed clearance conditions induce sediment scour due to the high speed jet generated by a rotating propeller. Sediment scour is known to cause instability to quay structures, damage to the bed protection and may create huge accretion areas reaching extremely low depths, preventing the free passage of large ships. This on-going problem is linked to the constant increase in commercial ship sizes and is widely recognized in current harbor management guidelines. This thesis presents in the first place the experimental work carried out to study the effects of two common propeller systems over the sediment bed: single and twin propellers. Next, the analysis of a case study is used to evaluate the impact of ship maneuvers over the seabed in a particular harbor basin. The first part of the thesis presents a set of experiments in propeller jet velocity and bed shear stresses. By measurements performed in a point-by-point grid, with a Pitot-static tube coupled to differential pressure sensors, the axial velocity distribution at the so-called efflux plane is characterized. After that, direct measurements of bed shear stress are performed at several speeds of rotation and two bed-clearance distances with a shear plate. Velocity and bed shear stress measurements are related by an empirical friction coefficient, which is dependent on the bed clearance. A new empirical model is presented to estimate the mean shear stress in case of unconfined ship propeller jets in low bed clearance conditions. The second part of this work shows the results of a new set of experiments in local scour due to confined twin propeller jets. The maximum scour depth is studied as a function of the bed clearance, the wall clearance and the efflux velocity of the jet. Aiming to reproduce more realistic maneuvers, scour due to forward and backward rotation of the propellers is analyzed, showing a different behavior compared to the traditional experiments with only forward rotation. Th, Els vaixells que maniobren en condicions de calat reduït poden provocar erosió local del llit de sediments a causa del raig d'aigua d'alta velocitat generat per les hèlix. L'erosió causa inestabilitat en les estructures dels molls, danys a la protecció del llit i pot crear grans àrees d'acreció, posant en risc la seguretat en la navegació. Aquest fenòmen està relacionat en gran mesura amb l'augment de les dimensions dels vaixells comercials en les darreres dècades i és àmpliament reconegut en les guies actuals de gestió portuària. Aquesta tesi presenta, en primer lloc, el treball experimental realitzat per estudiar els efectes erosius provocats per dos dels sistemes de propulsió més comuns: hèlix convencional i sistema de doble hèlix. A continuació, s'utilitza l'anàlisi d'un cas pràctic per avaluar l'impacte de les maniobres dels vaixells sobre el fons marí en una dàrsena portuària concreta. A la primera part de la tesi es presenten i s'analitzen en un conjunt de mesures experimentals de velocitat del flux d'aigua a la sortida de l'hèlix i de tensions de tall sobre un llit horitzontal. La distribució de velocitats axials es caracteritza a partir de mesures puntuals preses amb un sistema de tub de Pitot-estàtic acoblat a sensors de pressió diferencial. Posteriorment es realitzen mesures directes de les tensions de tall al llit amb una placa de tensions (shear plate) a tres velocitats de rotació de l'hèlix i dues distàncies verticals sobre el llit. Les mesures de la velocitat i la tensió de tall es relacionen amb un coeficient de fricció empíric que és dependent de la distància al llit. A la segona part d'aquest treball es presenta un nou conjunt d'experiments en erosió local per sistemes de doble hèlix confinats. La profunditat màxima d'erosió s'estudia en funció de la distància al sòl, la distància a la paret i la velocitat de sortida del raig d'aigua. Amb l'objectiu de reproduir maniobres de vaixells en entorns portuaris, s'analitza l'erosió generada pels sistemes, Postprint (published version)

The impact of the SARS-CoV pandemic has gone well beyond health concerns, reaching the maritime industry. The study on the environmental impact of shipping industry during COVID-19 pandemic can provide useful insights to propose new management policies regarding shipping operations, both in-port and on the route. We present a case study centred in the Port of Barcelona covering a 30 nautical miles range in the period March to July 2020, during which different levels of restrictions and stringent lockdown measures were enforced. In this paper, we assess the impact of COVID-19 on maritime traffic and its related emissions in port cities using real-time Automatic Identification System (AIS) data. Interestingly, results show that the decline in maritime traffic is not correlated with a decrease in maritime emissions due to changes in vessel operation. During lockdown (March to June 2020), we observed a 27.9% reduction in the number of port calls compared to the pre-lockdown scenario, whereas pollutant emissions show a moderate decrease (1.8% for CO2), no significant reduction (SO2 and PM) or a slight increase (1.3% for NOx). This can be directly assigned to changes in vessel operation mode, i.e. vessels switched from Underway to At Anchor or Moored status, during which auxiliary engines are used at higher loads., Postprint (author's final draft)

L'erosió de el fons marí a les dàrsenes i, en concret, de les banquetes i talussos dels molls, és un fenomen que ocorre per l'acció erosiva dels corrents generades pels sistemes de propulsió dels bucs, capaços d'assolir velocitats molt majors que les que es puguin donar de forma natural en els ports. A la llarga, aquesta erosió pot desencadenar fallades estructurals i geotècnics en les obres d'atracada dels ports, per la qual cosa és crucial prevenir aquest procés. En aquest estudi s'ha realitzat una anàlisi de les diferents metodologies presentades en aquest sentit a les publicacions de referència per a l'execució de projectes d'enginyeria marítima, la ROM i la PIANC. Aquesta anàlisi s'executa mitjançant la valoració relativa dels resultats obtinguts en funció del mètode utilitzat i de el cas d'aplicació, amb el propòsit de dotar l'enginyer o enginyera d'una visió general de el problema i de el coneixement del que es pot esperar en funció de les decisions preses. Com a part de l'anàlisi, s'han avaluat, primer, un total de 42 bucs comercials reals, operant en una sèrie de molls tipus per analitzar la sensibilitat de les formulacions. A continuació, s'ha estudiat un cas real d'un port que ha patit els efectes d'aquest procés erosiu. De l'anàlisi comparativa es conclou que el mètode ROM considera velocitats de flux molt superiors als de la seva homòloga internacional, la PIANC, el que es tradueix en requisits de dimensionament molt més grans. Amb el mètode holandès que es presenta a la PIANC, en canvi, s'obtenen valors sospitosament petits en vista dels danys registrats en molls amb esculleres petites on operen bucs comercials. El mètode alemany de la mateixa publicació, finalment, mostra una sensibilitat a el resguard considerable, acostant-se als resultats de les ROM a resguards restringits i disminuint fins a valors del mètode holandès en el cas de resguards folgats., La erosión del fondo marino en las dársenas y, en concreto, de las banquetas y taludes de los muelles, es un fenómeno que ocurre por la acción erosiva de las corrientes generadas por los sistemas de propulsión de los buques, capaces de alcanzar velocidades mucho mayores que las que se puedan dar de forma natural en los puertos. A la larga, esta erosión puede desencadenar fallos estructurales y geotécnicos en las obras de atraque de los puertos, por lo que es crucial prevenir este proceso. En este estudio se ha realizado un análisis de las distintas metodologías presentadas a este respecto en las publicaciones de referencia para la ejecución de proyectos de ingeniería marítima, la ROM y la PIANC. Dicho análisis se ejecuta mediante la valoración relativa de los resultados obtenidos en función del método utilizado y del caso de aplicación, con el propósito de dotar al ingeniero o ingeniera de una visión general del problema y del conocimiento de lo que se puede esperar en función de las decisiones tomadas. Como parte del análisis, se han evaluado, primero, un total de 42 buques reales, operando en una serie de muelles tipo para analizar la sensibilidad de las formulaciones. A continuación, se ha estudiado un caso real de un puerto que ha sufrido los efectos de este proceso erosivo. Del análisis comparativo se concluye que el método ROM considera velocidades de flujo muy superiores a los de su homóloga internacional, la PIANC, lo que se traduce en requisitos de dimensionamiento mucho mayores. Con el método holandés que se presenta en la PIANC, en cambio, se obtienen valores sospechosamente pequeños en vista de los daños registrados en muelles con escolleras pequeñas dónde operan buques comerciales. El método alemán de la misma publicación, por último, muestra una sensibilidad al resguardo considerable, acercándose a los resultados de la ROM en resguardos restringidos y disminuyendo hasta valores del método holandés en el caso de resguardos holgados., Erosion of the seabed in harbours and, in particular, of quaysides and quay slopes, is a phenomenon that occurs due to the erosive action of currents generated by ship propulsion systems, which are capable of reaching much higher speeds than those that can occur naturally in harbours. In the long run, this erosion can trigger structural and geotechnical failures in the berthing works of ports, so it is crucial to prevent this process. In this study, an analysis of the different methodologies presented in this respect in the reference publications for the execution of maritime engineering projects, ROM and PIANC, has been carried out. This analysis is carried out by means of a relative assessment of the results obtained depending on the method used and the case of application, with the aim of providing the engineer with an overview of the problem and the knowledge of what can be expected based on the decisions taken. As part of the analysis, a total of 42 real ships have first been evaluated, operating at a number of typical docks to analyse the sensitivity of the formulations. Then, a real case study of a port that has suffered the effects of this erosion process has been studied. From the comparative analysis, it is concluded that the ROM method considers much higher flow velocities than its international counterpart, PIANC, which results in much higher design requirements. The Dutch method presented in PIANC, on the other hand, results in suspiciously small values in view of the damage recorded in piers with small breakwaters where commercial vessels operate. The German method of the same publication, finally, shows a considerable sensitivity to the keel clearance, approaching the ROM results in restricted guards and decreasing to Dutch method values in the case of slack keel clearance.

We present a new set of experiments in local scour due to confined twin propeller jets aiming to include propeller driving characteristics to the analysis of the scouring action during in-port manoeuvres. The maximum scour depth is studied as a function of the bed clearance, the wall clearance and the efflux velocity of the jet. Aiming to reproduce more realistic manoeuvres, both forward and backward rotation of the propellers are analysed showing a different behaviour. The obtained results are used to propose two different empirical models, one for each regime of rotation. A new non-dimensional parameter obtained from the Buckingham p analysis, proposed as wall Froude number, is used to find a clear threshold triggering the scouring mechanism. The experimental results show that the distance to the vertical wall is the main contributor to the higher scour depths rather than the propeller speed of rotation or the bed clearance., This work has been supported by MINECO (Ministerio de Economía y Competitividad) and FEDER (Unión Europea- Fondo Europeo de Desarrollo Regional “Una Manera de hacer Europa”) from Spanish Government through project TRA 2015-70473-R. The first author was supported by a PhD grant (FI-0.2018) from the Government of Catalonia. This work received also support from the Departament d’Universitats, Recerca i Societat de la Informació of the Government of Catalonia (file 2017 SGR 773). AMC acknowledge the support from the Serra Húnter program., Peer Reviewed, Postprint (published version)

The increase in marine traffic during the last decades has led to important changes in ship designs. These changes have been directly affecting harbor structures designed to host smaller and less powerful ships. One of the most important consequences is the erosion of the seafloor close to the toes of the docking infrastructures which affects their stability. The World Association for Waterborne Transport Infrastructures published a guideline resuming the most used equations to solve the scouring problem (PIANC 2015). However most of the proposed formulas are empirical based using single propellers. Other common propulsion systems, such as the twin propeller, have been barely studied so far. Moreover, the propeller scouring action by a free developing jet has received much more attention in comparison with confined scour studies, i.e. nearby marine structures. Indeed, only one reference (Mujal-Colilles et al. 2018) with experiments on the effects of twin propeller in a confined scenario is found nowadays, although it is known that most of the ro-ro and ferry ships use this propulsion system when maneuvering near closed quays. This contribution aims to provide new insights about the effects that twin propeller propulsion system has over the seabed through a set of experiments with mobile sand bed. The effects of the propeller pitch ratio are also evaluated in an attempt to better reproduce the behaviour of ferry ships, since most of them use a Controllable Pitch Propeller (CPP) system., Postprint (published version)

Scouring and sedimentation effects on the seabed induced by ship propellers during ship manoeuvring near harbour structures affect both structure stability and ship manoeuvring capabilities. This contribution proposes solutions at an operational level using the automatic identification system (AIS) and a bridge simulator. Two new alternative manoeuvres were designed and tested on a bridge simulator to obtain expected maximum scour depth and the results were compared with that of real manoeuvres (i) using mooring lines, and (ii) with tug assistance. A total of 42 test scenarios combining several manoeuvres and meteorological conditions were reproduced. Results confirmed a clear reduction in erosion depth with the alternative manoeuvres, with total reduction when using the tugboat. The presented methodology can be very useful to port authorities to prevent the effects of ship erosion on harbour infrastructures., Projecte finançador : Simulación y Monitorización para pronóstico de la erosión en ámbitos portuarios :TRA2015- 70473R, Postprint (author's final draft)

Erosion of the seabed is produced by cargo and passenger vessels when manoeuvring in a harbour basin due to the high-speed jet flow generated by the main propellers. In case of twin propeller vessels, the ability to perform the whole manoeuvre with no tugs makes the master to use the main propulsion system even close to berthing walls and other structures. Near quay walls, the main variables leading to sediment scour are both related with the propeller behaviour -speed of rotation, pitch- and with the relative position of the propeller to the quay wall and the seabed -axial distance to the quay wall and vertical distance to the seabed-. Therefore, there exists a need to understand the manoeuvre in detail in order to predict the actions of the propellers to the seabed. In this article, AIS data is used to study the target manoeuvre to later reproduce it in the ship simulator. With the output of the simulator, timeseries of the propeller delivered power and the position of the propellers during the manoeuvre are obtained. With these data, the existing formulae in maritime engineering can be applied to obtain the efflux velocity at every ship position. By linking the efflux velocity with the manoeuvre characteristics, -i.e., ship position, ship heading and distance to the quay walls and seabed semiempirical formulation to obtain the flow velocity over the seabed and the expected scour depth is also applied. The numerical simulator turns out to be a very useful tool to analyse any manoeuvre and obtain the locations where it is potentially more harmful, the expected flow velocity and the maximum expected scour depth.

The jet flow generated by manoeuvring ships nearby vertical structures is known to erode the seabed sediment but is still difficult to predict the effects of a particular ship operating in a harbour basin. This paper presents a methodology to quantify the scouring action generated by ship's propellers combining field and real data with a manoeuvre numerical simulator testing some of the most commonly used formulas for maximum scouring depth prediction. From the real manoeuvres, analysed through Automatic Identification System (AIS) data, the manoeuvre patterns are identified to be later reproduced at the simulator, thus obtaining the propulsion system behaviour to apply the formulae and to estimate the maximum erosion depth expected in a harbour basin. The obtained results are validated with field data from bathymetries and Acoustic Doppler Velocimeter (ADV). Results show the arrival and departure manoeuvre sections where the vessel is potentially harmful. The different formulae applied yielded results in accordance with the provided bathymetry of the study area in terms of maximum erosion depth. Also, the areas of maximum expected seabed velocity are coincident with the areas where the maximum scour is observed in the bathymetry., Peer Reviewed, Postprint (published version)

Demostrar com les maniobres del Cruise Roma afecten sobre l’estat del moll del Morrot i veure quines de les maniobres alternatives es poden realitzar per tal de reduir aquestes erosions.

Postprint (author's final draft)

The evolution of shipping industry in terms of bigger and more powerful ships, is causing several issues in existing ports and marinas designed, initially, to host smaller vessels with smaller propulsion systems and lower drafts, such as harbour basin erosion near quay walls, deposited zones in low frequented areas and reduction of operational areas. Previous studies concluded that main problems come from regular vessels such as ferries, which dock and undock frequently in the same quays performing the same manoeuvres. This contribution deals with a method to reproduce real ship manoeuvres in a full mission ship imulator obtained through Automatic Identification System (AIS) data analysis. A faithful reproduction permits to extract propeller and propulsion variables, which, in turn, allow the study of the scouring action using literature formulae. Results obtained show that AIS data can be used to obtain manoeuvring patterns, allowing the study of the scouring action for every particular case depending on vessel type, manoeuvre or met-ocean conditions., Postprint (published version)

The shipping industry evolution over the last decades has led to growing structural and operational problems, in particular, for old marinas with lower depths to hosts present ships and with higher drafts and power of engines. The increase in capacity, size, power and self-propulsion of present ships is the main cause behind morphodynamic sea bed changes in harbour basins. This is producing two different but linked problems: scouring effects near the structures, affecting their stability, and sedimentation of the scoured material in other areas of the basin that reduces the average depth of the basin and the ship motions become uncontrollable. The present contribution aims to compare two different manoeuvring situations in a confined scenario, using laboratory data. Laboratory experiments have been carried out at the Marine Engineering Laboratory facility LaBassa. The two manoeuvring situations, modelled at bollard pull condition are permanent docking/backward and permanent undocking/forward using three different propeller revolutions at a fixed pitch angle and blade area ratio and two fixed locations of the propellers from the wall. The potential erosion is measured through an ecosound scanner of the control area over a homogeneous sandy bed. The evolution of the maximum erosion depth behaviour is completely different for undocking and docking operations. Undocking/backward results show higher depths at the initial stages reaching an almost asymptotic state at the end of the experiments whereas maximum erosion depth during forward operations increases monotonically over time., Postprint (published version)

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., Postprint (published version)

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. The se variables, all related to ship’s propeller behaviour, are the rotational speed, the pitch ratio and the engine powerduring 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., Postprint (author's final draft)

El objetivo que persigue este trabajo es el de realizar los primeros pasos en la creaci´on de un sistema de cálculo de estabilidad para el sistema ACTIONTRUCKER, un sistema inteligente de monitorizaci´on de buques que permita el acceso a informaci´on relevante a armadores, terminales, agencias, explotadores y otros actores interesados a trav´es de internet, informando y actualizando continuamente de las variables m´as representativas de la seguridad del buque. La base desde la que se parte es la de la transmisi´on de datos desde diferentes partes del buque a partir de una red de conectividad centralizada en un procesador compuesto por placas de arduino y Rasberry Pi, que ser´an capaces de procesar el vol´umen de datos recibidos y transformarlos en informaci´on ´util para los interesados. Como sabemos, el buque es un activo de gran valor que requiere un buen control de la actividad segura. Este instrumento pretende llegar a los buques tanto de recreo como profesionales y adaptarse a cada uno seg´un sus necesidades para poder conocer el estado de los puntos clave del buque en todo momento y a trav´es de la pantalla. ACTIONTRUCKER quiere incorporar sensores para el control de puntos calientes en el buque y, consecuentemente, la prevenci´on de incendios; sensores de agua para detectar v´ıas y prevenir inundaciones; un aceler´ometro para detectar posibles consecuencias despu´es de una colisi´on, seg´un el impacto detectado; sistemas de control de accesos a puntos restringidos; sensores de vibraciones para control de calidad de l´ıquidos y motor; sensores de calado para control de carga y c´alculo de estabilidad y un sistema de mantenimiento proactivo para control de tareas como repostaje, control de niveles, revisiones de equipos y motor.