Usporedba glavnih značajki klasičnog i vakuumskog načina prikupljanja i odvodnje sanitarne otpadne vode na brodu za rasute terete

Dana je usporedba klasičnog i vakuumskog sustava odvodnje sanitarne otpadne vode iz nadgrađa broda za rasute terete od 52000 tdw s 25 članova posade. Sustavi se uspoređuju prema potrošnji svježe sanitarne vode, trošku za proizvodnju potrebne količine svježe vode, vrijednosti materijala i rada potrebnog za izradu sustava, energiji koja se troši za funkcioniranje sustava i troškovima održavanja. Rezultati analize pokazuju da vakuumskim sustavima odvodnje treba dati prednost pri ugradnji. Niži troškovi u eksploataciji brzo nadoknađuju veće početno ulaganje

FLOATING CRANE RESPONSE IN SEA WAVES

Many activities present in the offshore technology are affected by sea waves and their safety strongly depends on the sea state. The fundamental question in operation risk analysis is the limit sea state which enables the safe operation controlled in all phases: from the sea surface to the sea bottom. The safe limit sea state is especially important when some lifting operation is performed in sea waves. This paper presents a dynamical model of a floating crane in sea waves with a hanging load at a high altitude above sea level. The model is defined as a linearized coupled double pendulum where the usual 6 DOF of the floating crane oscillatory motions in waves are extended by additional 3 DOF of the swinging load. The numerical model of the floating crane is calibrated and tuned according to the measured model in a towing tank. The significant values of the crane boom top accelerations were estimated for the given design sea state with different vertical load positions. The problem is illustrated by the example of a floating crane consisting of a simple single pontoon with an ordinary land crane mounted on the deck. The reliability of the proposed method is evaluated on the basis of correlation between the calculated and measured data

Primjena ekonomskih mjerila vrsnoće u osnivanju broda

Za zadane vrijednosti nosivosti, brzine te omjera glavnih dimenzija i koeficijenta iskoristivosti istisnine osniva se inicijalni brod. Varirajući duljinu i omjere glavnih dimenzija inicijalnog broda osniva se flota brodova. Za sve brodove iz generirane flote izračunavaju se ekonomske značajke za različite kombinacije brzine, kamata i životnog vijeka. Tretirajući ove značajke kao ekonomska mjerila vrsnoće biraju se najbolji brodovi prema: najmanjem trošku izrade, najmanjem trošku izrade po toni nosivosti, najvećem koeficijentu iskoristivosti istisnine, najmanjim životnim troškovima po toni nosivosti, najmanjoj zahtijevanoj vozarini, najvećoj dobiti po toni nosivosti, najbržem povratu kapitala i najvećoj sadašnjoj vrijednosti projekta. U radu je utvrđeno da u izboru najboljeg broda prevladavaju ekonomska mjerila u odnosu na tehničke kriterije

Ekonomska mjerila kao kriterij u osnivanju broda

Pojavom standardnih pravila u projektiranju brodova, a koja su u većini prihvatila klasifikacijska društva dolazi do ujednačavanja kriterija za gradnju brodova. Primjenom novih pravila značajno će se produžiti efektivni vijek trajanja broda i to na 35-40 godina u odnosu na današnji prosjek od 25 godina što vodi relativnom skraćenju vremena amortizacije. Trošak goriva postaje glavni čimbenik optimizacije te naspram kutijastih formi s maksimiziranim blok koeficijentom i omjerom B/T razmišljanja idu ka vitkijim i "normalnijim" formama. Da bi postigli uspjeh u novim projektima uz analize već stečenog znanja moramo učiniti korak natrag i uložiti veći napor u fazu konceptualnog projektiranja uz oprez da se ne oslanjamo samo na jedan kriterij ekonomskih mjerila nego na višekriterijalnoj analizi i analizi senzitivnosti više ekonomskih mjerila uz puno poznavanje tržišta i svih njegovih mehanizama

UNMANNED SURFACE VEHICLE – TRITOR

This paper presents an unmanned surface vehicle Tritor that was developed, constructed, and tested within an innovative, multi-purpose, multidisciplinary, low-budget and environmentally friendly solution. The idea behind this work was trying to invent a new concept of a miniature surface vehicle that will be unmanned, remotely controlled and autonomous, with electric propulsion, and with an innovative Three Slender Cylinders Hull (3SCH) form gaining advantages in comparison to existing surface vehicles. This initial work is focused on vehicle prototype design, propulsion system development and optimization, control design, and trials, while research related to advantages of the vehicle in terms of naval architecture criteria such as drag and power, stability, seakeeping, and maneuverability will be investigated in further work. In addition, the paper intends to contribute to a new trend in developing vehicles with electrical propulsion that could use renewable sources of energy such as wind and solar energy. The potential usage of the vehicle can be civilian or military, and further work will be focused on larger models, improved based on the experience got during the development of the vehicle. Tritor vehicle was successfully designed, constructed, and tested in real environmental conditions. The preliminary results show that the vehicle has required performances and potential for improvements in the future. The main scientific contribution of this work is advanced surface vehicle development with a focus on a new hull form and the integration of electric propulsion in it

CURRENT APPROACHES TO THE MANAGEMENT OF NAVAL SHIPBUILDING PROJECTS

The paper deals with the analysis of development and trends in the field of management of naval shipbuilding projects. The introductory part gives an overview of project management in the defense sector as well as in the naval shipbuilding sector. The analysis of naval shipbuilding project management is done through consideration of four criteria: naval strategy and long-term planning, shipbuilding industrial base, workforce, and project management organization. Due to limited resources, five countries were selected: the United States of America (USA), the United Kingdom (GBR), Australia (AUS), New Zealand (NZL), and Croatia (HRV). After individual countries have been analysed, synthesis and comparison of results were presented in tabular form. The conclusion is based on global trends in this area, how the naval shipbuilding project management in the Republic of Croatia is harmonized with them, and recommendations for improving the process of managing naval projects in the Republic of Croatia. The scientific contribution of the paper is in defining a systematic approach to managing naval shipbuilding projects that could serve as a generic model on which the future organization and management processes of naval shipbuilding projects in the Republic of Croatia and other maritime countries, that are comparable in economic strength and defense needs, may be founded

Pomorska baština i praktična edukacija

Očuvanje pomorske baštine kao dijela cjelokupnog kulturnog nasljeđa jednog naroda ima važnu ulogu u formiranju identiteta i prenošenju iskustva na nove generacije studenata. Istovremeno je niz djelatnosti u području male brodogradnje postalo zanimljivo kao predmet sustavnog proučavanja, te je tako pobudilo interes studenata za tehničke, tehnološke i inženjerske probleme struke. Spajanjem ovih dviju komponenti potaknuta je organizacija Ljetne škole male brodogradnje koja bi obuhvatila tehnički i kulturni aspekt djelatnosti. Od 2013. do 2016. godine održane su 4 ljetne škole na kojima je ukupno 40 studenata steklo praktični uvid u probleme gradnje i projektiranja malih brodova. Istovremeno su temeljito upoznali tradicijske brodove te proveli praktična mjerenja forme na njima. Rezultati studentskog rada pokazani su putem kompjuterski izglađenih nacrta brodskih linija koji ujedno služe očuvanju informacija o brodovima za koje postoji ozbiljna opasnost da se u potpunosti izgube i nestanu

Alternate Approach to Redundant Propulsion as a Result of a Risk Management Policy

Propulsion reliability, vessel and environment safety are signifi cant reasons for redundant propulsion demand. Costs involved in the class notation Redundant Propulsion (RP)1 2x50% make this application costly and less attractive. Searching for technically and commercially viable solutions while Classifi cation Societies have not yet unifi ed the rule requirements is a challenge for ship owners and shipyards. This paper considers the limits in Power Take In (PTI) application in slow speed propulsion plants and related potential diffi culties. In addition, the example of lower sized PTI application in practice, without assigned notation, is reported