Naval Engineering

MGPS Cofferdam is an equipment to be attached at the submerge part of the ship’s hull, to create an watertight environment for the safety cutting, welding, or another underwater activities. The activity here for the MGPS Cofferdam is the changing of the rise pipe at side of the submerged part of hull.

En este trabajo de fin de máster, se ha realizado una evaluación de riesgos laborales en buques mercantes, para proponerlo como un modelo y estandarizar el proceso llevado a cabo.
El proceso de evaluación de riesgos, se basa en la evaluación general de riesgos que el Instituto Nacional de Seguridad e Higiene en el trabajo expone en su manual de referencia.
Debido a la alta siniestralidad de los incendios ocurridos a bordo de los buques mercantes, se ha realizado un análisis del riesgo de incendio.
Una vez realizada la evaluación de riesgos, se han identificado aquellos riesgos catalogados como moderados e importantes y se exponen las medidas necesarias a implantar con el objetivo de eliminar o reducir y controlar dichos riesgos.

The writings that most closely belong to the discipline of history, and in particular the history of shipbuilding, are papers containing arguments quite different from each other, or very informative or very specialized. The scientist is often embarrassed in reading these books because they are written from a humanistic, and they are not scientific-technical papers, sometimes they are complemented with mathematical formulas and diagrams written in obsolete languages, designed to discern the paths of history passed, and adjacent to a discipline that looks to the near future and not in the past, a history too often forgotten. The Scientia navalis or Naval Science, which Leonhard Euler (1707 - 1783) was a teacher and somewhat precursor, from time immemorial languishing on the shelves of libraries, neglected by scholars. This occurred because the discipline has come to self-awareness, especially in the contemporary age, when, following the example of the Galilean revolution, the community of surveyors and scholars of mechanics oriented his attention to the problems of shipbuilding and vessel operations, which at first seemed disciplines entrusted only to the skill of the shipwright, carpenters and the Masters and Shipmasters on board ships, as well as to the wisdom of tradition. History, however, is a fascinating and fruitful field of study for some guidance because by understanding what has been achieved in the past, has been able to establish a more consistent definition of science and technology to be used in applied in the design and construction. Even for shipbuilding, in fact, the sedimentation of knowledge of the past passed down orally by the shipwright to their students and then taught in the schools of Naval Engineering in France scrolls and founded by Jean- Baptiste Colbert (1619 - 1683) Secretary of the French Navy in the seventeenth century, has been able to point the way to address and solve static and structural problems, but also those related to material behaviour and then, thanks to the Enlightenment of the eighteenth century, those relating to navigation and manoeuvring of vessels. Only in this way it was possible to achieve those goals of technical and technological developments that have allowed the massive shipbuilding industry in the nineteenth century, following the same “logic” that guided the ancient builders and shipwrights, thus obtaining accurate and effective design and construction solutions.

A hydrofoil craft is known for the ability to lift its hull out of the water, increasing the hydrodynamic efficiency of the boat. This work details the experimental process of developing a computational control system for the foils of a prototype hydrofoil craft. The thesis objective is to develop a control law that when combined with a careful integration of mechanical and electronic components, can maneuver the hydrofoils. Optimal linear quadratic regulators and PID control were the methods utilized. Successful foil control laws were obtained. The foil control system achieved is intended to serve as the foundation for craft motion control, a necessary element for applications in marine dynamics.

Pre-and post-swirl fins-based energy-saving devices (ESD) are designed to improve the propulsive performances of a twin-screw ship. To this aim, BEM and RANSE calculations are employed. Depending on the application, a simple actuator disc model (post-swirl) with radially varying load or a combined BEM/RANSE method for self-propulsion prediction (preswirl) are required. Both the approaches are included in a framework for a design by optimization, where systematic variations of the ESD geometry are used to explore the design space and maximize the energy-saving effect of the devices. Considering the particularity of the case selected for the study, results show encouraging improvements that reach a promising 5% in the case of the combined action of both devices.

This article discusses several minor refinements to Titanic's design based on experience with some specific riveted joints on Olympic (similar changes were then incorporated into Olympic and Britannic).  It is a greatly expanded version of an article originally made available on the Titanic Research & Modelling Association (TRMA) website in 2005, which published information about these changes for the first time.  This expanded article appeared in the British Titanic Society journal Atlantic Daily Bulletin in December 2019.

NASCITA ED EVOLUZIONE DEI CONTAINERS

Una rivoluzione recente quella dei containers e del trasporto marittimo degli stessi, una rivoluzione strisciante che oggi è diventata condizione del benessere, una rivoluzione scarsamente percepita dall’ opinione pubblica sino a che la sua importanza non è apparsa in tutta la sua gravità e implicazioni in occasione dell’ incaglio di una mega-portacontainers nel canale di Suez.
Oggi si parla di portacontainer da decine di migliaia di TEU, numero enorme di “pezzi” la cui movimentazione richiede una organizzazione complessa ma anche capillare, attenta ai minimi dettagli, nonché una attenta gestione tecnico-nautica della nave
Al gigantismo delle “navi madre” che possono solo scalare terminali attrezzati, sempre più specializzati, si è aggiunto il controllo di questi “snodi” da parte  della stesse “mani”, pochi operatori che, abbiamo visto nella “prova generale” del blocco del Canale di Suez, possono mettere in ginocchio l’ economia mondiale, agendo su poche leve di comando.

Come si è giunti a questo? come premessa ad un’ analisi di questa situazione, è utile conoscere come, in pochissimi anni, si sia arrivati a questa gestione degli scambi, in particolare per la parte marittima.

Questo articolo è stato originalmente richiesto, a fini divulgativi,  da Italian Shiplovers per pubblicazione nel dicembre 2020

Pada dasarnya dalam mererncanakan sebuah kapal, semuanya harus memenuhi syarat-syarat regulasi, tujuan dari dirancang dan diterapkannya  regulasi tersebut salah satunya untuk keselamatan kapal itu sendiri karena menyangkut kehidupan orang yang ada dikapal. Begitu juga dengan Special Purpose Ships (SPS) juga harus memenuhi persyaratan regulasi yang berlaku. Kali ini Penulis akan memaparkan lebih lanjut kaitannya dengan regulasi SPS kaitannya dengan Machinery Installations yang akan dijelaskan dalam Bab Pembahasan.

The Future Frigates Program SEA 5000 is the largest naval shipbuilding project in Australian history, the centre piece of the continuous National Naval Shipbuilding Enterprise. This paper, by former Parliamentary Secretary for Defence David Feeney shows that Australia will be paying nearly double per frigate as compared to the contemporary US and UK Frigate programs. Even though the Strategic Update 2020 highlights Australia’s rapidly deteriorating strategic environment, Feeney shows the Government has deliberately structured the frigate program so that it delivers capability more slowly (extended to 2044) and at greater cost (an additional A$9.3 billion). He argues the key reason for this deliberate slow down in the construction rate of the frigates is to enable the “implementation of a stable, deliberate and continuous shipbuilding drumbeat” so as to “end the ‘boom and bust’ cycle of naval shipbuilding, delivering sovereign capability and certainty for industry.” The paper explores the challenges of shipbuilding, the policy tensions and trade offs, and offers suggestions for how to get SEA5000 back on track.

The method of analysis of cavitation in marine propellers that takes into account the Burrill Diagram is one of the most used by designers worldwide. The literature has reported this technique as reliable and quite useful in the design of fixed pitch conventional propellers. However, an accurate execution of the method shows that the calculations for cavitation at 2.5% on the back of the blades can indicate this percentage as having happened after cavitation at 10% or even after cavitation at 20%, which makes it physically impossible. In  addition,  there  may  be  negative  values of  expanded  area,  which  results  in  a  wrong indication of cavitation. In this sense, cavitation prediction calculations for five diameters were performed: a small commercial component of 0.25 m, a large of 10 m, belonging to a large oil vessel and three intermediaries, for comparison of results and reinforcement of conclusions. Within the examples of propellers tested, it was possible to conclude that the Burrill  Diagram  works  well  for  constructive  blade  angles  between  60  and  67  degrees, paired  with  a  45-degree  angle,  with  an  inclination  to  the  left.  But  most  of  the  time,  it provides false indication of cavitation for angles less than 60 degrees and greater than 67 degrees. It was also possible to verify that the larger the propeller diameter, the smaller the error range in the 2.5% cavitation indication. In view of these facts, the Burrill Diagram method does not become invalid, but it is concluded that it must be used with due care, within the indicated safety range.

Much has been written on the use of lead and copper sheathing in post mediaeval shipbuilding, yet evidence for such hull protection by Dutch shipwrights in the 17th and 18th centuries has received little attention. A discussion of the archaeological and historical evidence pertaining to the application of copper and lead sheathing by the Dutch long-distance trading companies outlines the argument for the innovative character, experimental use—on ships’ hulls—and standardization—on sternposts—as early as 1602. Archaeological evidence presented mainly comes from the Dutch East Indiamen Nassau (1606), Mauritius (1609), Batavia (1629), Vergulde Draak (1656), and Buitenzorg (1760).

Este projecto, teve como objectivo proceder à reconstrução de uma nau quinhentista, com base em informação arqueológica e documental, e analisar as suas características físicas e o seu desempenho. Com base nas fontes iconográficas, documentos da época e nas peças encontradas no fundo do rio Tejo junto ao forte de São Julião da Barra (referentes a uma nau naufragada em 1606), é possível estabelecer configurações plausíveis para o desenho das formas do casco e aparelho destes navios, e testá-los por meio de processos científicos, em ambientes controlados.

Un tema trito e ritrito su cui si sono spesi inutilmente fiumi di inchiostro Nessuna difesa di inventori o primogeniture che non hanno alcun valore in una gestazione che è stata una scoperta collettiva e non può essere il vanto di un singolo, o di un gruppo Nessuna intenzione di trattare ancora né di elettronica, frequenze e prestazioni né di scontri il cui successo sia stato condizionato dal radar; ... solo una serie di spunti, basati non sulla definizione di quali studi o progetti fossero più o meno avanzati o validi, da una parte o dall' altra, sugli aspetti industriali, su quanto e come nuovi concetti si fossero veramente trasformati in tecnologie e, ancora più importante in dottrine di impiego, da lì, quanto e come avessero avuto pratica applicazione in produzioni industriali ed in quali serie, con quali aspettative e soprattutto con quale accettazione. Non voglio né tanto meno posso parlare di prestazioni ma solo di diffusione degli apparati, in primo luogo dal punto di vista delle serie industriali e di allestimento delle unità Un lavoro sui radar sviluppato da un GN appare certamente strano se non fuori luogo: non deve preoccupare, non parlo né degli " apparecchi " né del loro funzionamento, sempre per me molto misterioso con quegli ingombranti, ed anche un po' pretestuosi ed esigenti, scatoloni con cui mi confrontavo a bordo, ma del radar come sistema integrato e di cosa ha comportato studiarlo, industrializzarlo, metterlo a bordo, utilizzarlo ed adattarsi a questo invadente vicino… Troppi libri zeppi di dati e di tabelle (per ingannare) scritti da personaggi che né sono mai stati su una nave né hanno la minima idea di cosa fosse in effetti un radar all' epoca … …ed anche in merito agli apparati radar " Gufo " , frettolosamente prodotti e tardivamente imbarcati sulle nostre navi maggiori, i racconti di quelli che li avevano " vissuti " citano solo caratteristiche mediocri, da far disperare i comandi in merito alla loro reale operatività, in continua contestazione con l'industria che li costruiva.

Proses pembangunan kapal merupakan suatu aktivitas yang dilakukan mulai dari perencanaan kapal (desain) sampai dengan penyerahan produk kapal kepada pemilik kapal. Pembangunan kapal ini dilakukan melalui suatu tahapan proses  yang salah satunya yaitu pembentukan blok – blok badan kapal yang dilakukan di building berth. Kemudian blok-blok tersebut disatukan menjadi blok yang  lebih besar di assembly area. Aktivitas penyambungan blok-blok kapal tersebut tidak lepas dari aktivitas pengelasan. Proses pengelasan ini sangat penting dikarenakan untuk melakukan joint bagian-bagian hull kapal. Dimana dalam proses pengelasan (welding) tidak boleh ada kesalahan sekecil apapun baik berupa crack, over heat, dan sebagainya. Proses pengelasan ini merupakan bagian yang amat vital dalam proses pembangunan kapal.
Maka dari itu dalam proses pengelasan diperlukan hal-hal yang harus diperhatikan oleh para surveyor dan para welder. Dalam makalah ini akan dibahas mengenai beberapa hal yang berkaitan dengan welding.

In recent years, numerous machinery health monitoring technologies have been developed by the US Navy to aid in the detection and classification of developing machinery faults for various Naval platforms. Existing Naval condition assessment systems such as ICAS (Integrated Condition Assessment System) employ several fault detection and diagnostic technologies ranging from simple thresholding to rule-based algorithms. However, these technologies have not specifically focused on the ability to predict the future condition (prognostics) of a machine based on the current diagnostic state of the machinery and its available operating and failure history data. An advanced prognostic capability is desired because the ability to forecast this future condition enables a higher level of condition-based maintenance for optimally managing total life cycle costs (LCC). A second issue is that a framework does not exist for "plug-and-play" integration of new diagnostic and prognostic technologies into existing Naval platforms. This paper outlines such prognostic enhancements to diagnostic systems (PEDS) using a generic framework for developing interoperable prognostic "modules". Specific prognostic module examples developed for gas turbine engines and gearbox systems are also provided.