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Standard buoyancy calculations refer to atmospheric air pressure. However, the effect of the weight of air underneath the waterline is not included as well as displaced air in tanks, structure and equipment above the waterline. A review of the theoretical mistakes in calculating buoyancy which includes comparison tables of data of different ship types. Suggestions for correcting the apparent mistakes are made. While per mille values for ships are small, per mille buoyancy is a few thousand kN. Documentation of real ships is used for correction of the actual mentioned air weights, thereby yielding precise ship weight and draft values.

The range of underwater vehicles from classical large submarines to deep sea vehicles (bathyscaphes, submersibles and submarines) is analyzed in this paper. Attention to the requirements for surface and underwater conditions including submerging/emerging processes is made. With classical submarines, buoyancy is satisfied by the inherent large pressure hull and corresponding appendages. However, deep sea vehicles which have smaller sized pressure hulls in order to satisfy strength and economic issues make use of syntactic foam. This paper provides a qualitative explanation of the development of chosen underwater vehicles. Special comparison of “Trieste”, “Deepsea Challenger”and “Mir” submersibles are discussed. Additionally, the experience of the main author’s collaboration in the preliminary design of the RONIO submersible is presented and its relevance to the topic of manned submersibles is explained.

Postoji jako puno odobalnih objekata i mnogi od njih se mogu izvesti u modularnom konceptu. Posebni, lako premjestivi i lako prilagodljivi budući odobalni objekti, namijenjeni novim turističkim izazovima, bit će posebno traženi. U ovom članku prikazano je nekoliko osnovnih ideja o projektima odobalnih objekata u rešetkastoj izvedbi, kao i u vulumnoj izvedbi.

“Design for production” principles have been applied in multiple industries with varying degrees of success. The shipbuilding industry has also started to apply these advanced principles for adapting vessel design towards production friendliness and vice versa. In order to maintain global competitiveness, shipyards must constantly improve upon existing processes in order to cut costs and increase profit. Therefore, in this paper the shipbuilding process of assembling interim products has been identified as an area where production costs could be reduced through the application of an improved “design for production” methodology. The two principle interim product assembly methods are analyzed and a work content analysis of a typical double bottom block is performed. In order for the application of the “design for production” methodology to be practical for shipyard management in making decisions with minimal risk with regards to choosing the most appropriate method for assembling interim products for the present technological state of the shipyard, risk analysis by use of the Monte Carlo method is undertaken. In this way, the application of the “design for production methodology” is improved upon and a new insight is developed concerning the optimal method development of interim product assembly for the future state with complementary adjustments to the shipyard technology level.

The comparison of measurement by means of modern nocontact digitizing system and traditional contact measuring system is the goal of the paper. Different measuring methods using nocontact and contact measuring systems are compared. Three-dimensional digitization could be defined as a process of measuring of enormous points number on a part in order to create a digital model of the same part in the numerical 3D form. Traditional coordinate measuring could be defined as a process of points collecting from an object by touching its surface. Sometimes, the using the traditional measuring machines such as mechanical 3D coordinate measuring devices, because of the large dimensions of the measuring object, is impossible and this opportunities gives a numerous advantages to digitizing systems (example study 1 in the paper). Presented example (example study 2 in the paper) of compared measurements shows that measurement of functional coordinates (plane, circle, slot, line and cone) at the same measuring conditions could be speed up a lot of times.

Na temelju urbanističkog projekta uređenja i dodatnog oplemenjivanja pomorskim sadržajima uvale Valkane započelo se s idejnim projektom višenamjenskog (plivanje, vaterpolo...) pomorskog bazena. Kako gotovo da i nisu postojali tehnički zahtjevi iste je trebalo definirati uzimajući u obzir: veličinu bazena, željenu mirnoću vode u bazenu, povezanost bazena s obalom, predvidivu razliku plime i oseke, izloženost utjecaju valova, sigurnost sidrenja bazena u iznimnim okolišnim uvjetima, vizualnu prihvatljivost, prihvatljivost cijene gradnje i troškova održavanja u eksploataciji. Prije konačnog definiranja preliminarnih tehničkih zahtjeva pristupilo se analizi mogućih varijanti projektnih rješenja (fiksna ; plutajuća ; fiksno-plutajuća), uzimajući u obzir financijska ograničenja te iznimno teške okolišne uvjete. Nakon izvršene analize svih relevantnih rješenja predlaženo je projektno rješenje pomorskog bazena olimpijskih dimenzija, dislociranog od obale i s jednim stupnjem slobode gibanja (os z) uzduž šest vertikalnih stupova. Projektom je predviđena laka rešetkasta konstrukcija iznad palube bazena koja omogućuje i zaštitu od vanjskih utjecaja. U slučaju ekstremno visokih valova predviđeno je da valovi preplavljuju cijeli bazen jer je predvideno ograničenje gibanja bazena i u vertikalnom smjeru.

Higher Education Success Stories and Model Programs

Autori su u ovom članku nastavili s istraživanjima uočenih grešaka u proračunu hidrostatike kod plovnih objekata zbog neuključenog zraka iznad i/ili ispod stvarne vodne linije. U radu je prikazano kako dolazi do pogreške pri konvencionalnim hidrostatičkim proračunima. Razlika pritiska zraka koji djeluje na površini vode i onog ispod trenutne vodne linije, odnosno iznad trenutne vodne linije, u konvencionalnoj metodi određivanja mase broda, se ne razmatra. Stvarne razlike u pritiscima zraka kod hidrostatskih proračuna utječu na ukupnu težinu broda, a time i na stvarni gaz broda. Na temelju uzgona dobivenog preko gazova i gustoće vode prikazan je korigirani izračun težine praznog opremljenog broda. Nadalje, autori su na temelju analize većeg broja brodova došli do dijagrama za korekciju gazova i težine broda proračunatom prema konvencionalnoj metodi, i to za različite dimenzije, odnosno u funkciji nosivosti za jedan tip broda.

Because of temporary environmental pollution caused by pollutant (engine and lubrication oils) from the “ Elhawi Star” vessel sunken not far off Rijeka break-water more than twenty years ago County Government purchased an ecology protection project. In condition of no relevant technical documentation and any other wrote documents have been on disposal, quantity and distribution of pollutants in tanks and other compartments was calculated on the base of similar vessel designs, and partially on eye-witnesses oral information. With underwater actions realised on the sunken vessel before ecology project activities started just some pollutions through air pipes in region of machinery space was terminated. On the base of overall investigation made on possible “ Elhawi Star” – environmental protection solutions, in final, author’ s proposal for long-term anti-pollution solution was accepted from County team. Shallow submerged chambers opened from the lower sides, fastened to rail plates and superstructure alongside machinery room in main in main deck region, represent the main pollutant collecting device. From the sunken chambers pollutants will be collected to the surfaced or submerged buoy by means of underwater piping system.

Based on a Space Joint Patent Application several space joints types were developed and implemented in various grid structures. Application of bigger cube space jointtype was realized in different fields. In this paper newest grid structures applications are described: Large TV Suspension Bridge ; Large Tie Node Grid Structure and Tie node Grid Structures Support Structure.

In this paper ecology condition of the sunken vessel MB ¨ELHAWI STAR¨ was analysed. Potential ecology intervention methods against pollutant blocked in sunken vessel tanks and spaces was described. Covered methods have been located to the two typical methods: a) Intervention methods on the sunken vessel, and b) Sunken vessel Lifting-up method. Although several ecology protection methods have been described and discussed, an implementation of a specially prepared additional open chambers, placed on the left sunken vessel side along the machinery space, have been suggested. Pollutants that come from the sunken vessel tanks and spaces will bi continuously collected within upper’ s open chamber. From the open chamber pollutants will be collected through small piping in to the surface buoy pollutants tank. Although sunken vessel surfacing possibility was under consideration that solution is not suggested because it will be very expensive.

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Pursuit of vessel because of criminal act is a very complex action. It demands to be treated as a special legal regime regulated in details and also supported with relevant design and equipment characteristics. A complex, synthetically approach requires interdisciplinary analysis of the number of different kinds of questions, and primarily numerous elements of navigational and technical nature. It is important to recognise their place and role in the pursuits structure as a whole, their interference and synthesis. That is the nucleus of the new functional approach towards the institute of pursuit, which, in the same time throws off traditional mechanical approach exclusive in its research (only from the standpoint of legal doctrine and practice) which, mostly, has been repressive in nature. While considering a vessels pursuit problem, as a whole, many of navigational questions are dealt with, like methods of fixing the position of vessel, navigational tactics of pursuit, manoeuvre of stopping of vessel, usage of radar, capacities and choice of pursuits devices, etc. These questions are considered from standpoint of their design and equipment relevance. Main technical points that are discussed are types of propulsion and steering systems regarding the pursuit vessels, such as conventional propeller with rudder, propeller within nozzle with conventional rudder, propeller within rotating nozzle with rudder, "Z" drive with vertical shaft in different configurations, water-jet propulsion, air-cushion vehicles, vessels with hydrodynamic buoyancy. Options for pursuit vessel stopping are described regarding intervention on: propulsion and steering systems, and vessel as a whole. Therefore, special equipment and devices for mentioned purposes are elaborated for interventions through air, surface, sub-sea and in combined mode. Also special systems that are employed for pursuit vessel stoppage are described in way of their configurations and particular characteristics. Special attention is given to new employed systems such as, underwater and surface nets, scattering missiles, surface anchoring equipment, etc. Application results of special equipment and devices for surface pursuit vessel stoppage are presented through corresponding theoretical approach.

The main objective of this article is to present theoretical and practical results and possibilities of different space joint types implementation in superstructures outfit and equipment. After introducing of new space joint types in light conventional grid structures, the authors are suggesting their implementation in various shipbuilding areas, and in particular within superstructure outfit and equipment. Space joint is a new constructional element for synchronous fastening of crossover rods in and/or on space joint body. At the same time the space joint represents a fastening node within grid structure. New grid structures solutions are based on Patent Cooperation Treaty (PCT), Patent Application No. PCT/GB97/00944, with International Publication Number W 97 / 38229 and some additional research results in this field. Some of present research activities supported by the Ministry of Science and Technology of the Republic of Croatia (Scientific project name: Marine structures and equipment in coastal zone and subsea) have also been presented. The main new grid structures building concept is characterised with structure lightness, simple assembly and adjusting procedures, "maintenance free" structures, ecology friendly structures, accommodation system modules with simplified on board erection possibilities, and multiple usage configurations. Analysing various present construction solutions in ship superstructures, masts, communication facilities, furniture, gangways, telescopic roofs, etc. the authors pointed out concrete proposals for new solutions regarding implementation of mentioned space joint types. Advantages with argumentation for particular topics were described and presented. Developed computer model for one space joint type was described. Computer modelling was performed on basis of finite element method. Special attentions were pointed out regarding contact pressures, deformations, as well as stresses. Up to date testing was mainly realised concerning small-reinforced polyamide type of space joint body and fastening bodies. Preparations for testing procedures of different types from various materials and dimensions have been discussed, too. Special consideration was given to compare theoretical and experimental results concerning forces, deformations, strengths, and contact problems, based on some scientific research results achieved at Faculty of Engineering University of Rijeka. In addition, different aspects of ecology, maintenance, mounting and dismounting procedures, safety, replacement, etc. have been discussed. On basis of mentioned theoretical, experimental and some exploitation results authors proposed usage of different space joint types for implementation in shipbuilding. Authors are also suggesting further research regarding implementation of new predicted space joint types to different fields in shipbuilding and marine structures.

Interactions between ocean engineering structures (well platforms) and the environment may cause environmental pollution to occur. It is important to know and monitor the sea contaminants, such us metals and other trace elements, and by oil. Sea water pollution level determination can be realized using several chemical and physical methods. Applied methods are X-ray spectroscopy, AAS, ICP and UV fluorescence spectroscopy. Seawater pollution with metals is determined through measuring their concentration within seawater samples. Samples are treated chemically and prepared for measurament. Excitation of characteristic X-rays is realized by radioactive source 109Cd. Advantage of this method over many other methods is due to the non-destructibility and multielementality nature of the method. By AAS and ICP several particular elements have been determined. These alternative methods are destructive and monoelemental. Seawater pollution with oil is measured by optical fluorescence spectroscopy and a visible optical area (V), by excitation with ultraviolet light (UV). This method is also non-destructive. Both pollution groups, by trace elements and oil, are subject of international conventions. Therefore, usage of this methods help both, seawater environment control, and its pollution prevention from maritime and ocean engineering objects.

While transferring fluids through sub-sea piping, those are exposed to changeable surrounding water temperature and sea current velocity. Therefore heat transfer from piping towards outer surrounding water or from outer surrounding water towards piping occurs. The objective is to calculate more precisely total heat energy transfer along sub-sea piping. For better understanding of hydraulic losses over long piping a special mathematical model was defined. The model is based on definition of finite piping segment heat energy transfer. Corresponding computer software for heat energy transfer calculation was developed and tested, mainly intended to solve specific ecology problems influenced by pollutant fluids blocked in sunken vessel tanks. Obtained results&#61602 ; analysis enables defining shape (cross sections) and variables such as: dimensions of the pipeline, wall thickness and material, and insulation thickness and material, etc. As conclusion authors suggest that by interactive calculation based on developed software it is possible to perform the analysis of piping heat transfer with the objective of whole piping system optimization. Computer processing results are graphically presented in three dimensions (3D) with the possibility to change any pair of above mentioned variables, that is illustrated on a deep sea piping system example.

Organizacija cjevarske radionice u modernom brodogradilištu.

In standard hydrostatics for seaworthiness and stability calculation procedures, especially for submersibles surface condition, various geometrical bodies are under cinsideration, such as cylindres, spheres, cones, etc. By analytical solving a moment of volume and a volume of truncated inclined cone up to the actual waterline an integral of special type was solved. Solved moments and volume of analysed truncated inclined cone up to that waterline was tested by means of Sympson's rules. In this article the analytical solution of above-mentioned integral is presented for the first time.

Authors propose a novel design and building concept of offshore structures designated for various purposes. Improvement in design and building solutions of surface and underwater structures including also underwater restaurants, habitats, diving chambers, gondolas, tunnels, towers, bridges, etc., is based on concept of modularization. Together with modular construction concept, possible contents, communications, building materials, exploitation locations, energy supply, wastage disposal, ventilation and air conditioning, as well as marine structures protection, safety and rescue are discussed. The main objective of this article is to present theoretical and practical results and possibilities of different space joint types implementation in mentioned structures. After introducing of new space joint types in light conventional grid structures, the authors are suggesting their implementation also in various shipbuilding areas. The main new grid structures building concept is characterized with structure lightness, simple assembly and adjusting procedures, "maintenance free" and "ecology friendly" structure characteristics, accommodation system modules with simplified on board erection possibilities, and multiple usage configurations. Analyzing various present construction solutions in offshore unit superstructures, masts, communication facilities, furniture, gangways, telescopic roofs, etc. the authors pointed out concrete proposals for new solutions regarding implementation of mentioned space joint types. Advantages with argumentation for particular topics were described and presented.

Spojni elementi mrežnih struktura

Mogući obnovljivi izvori energije u priobalju i podmorju hrvatskog dijela jadranskog mora.

Authors pointed out the espied errors in weight and drafts estimation within surface vessel and especially naval submarine hydrostatic calculations. They demonstrate how these errors came from present vessel weight calculation procedure that is based on constant air pressure relevant to water surface level. Influences of differences in air pressure above actual waterline as well as air pressure under actual waterline that are not included in present procedure are described. With their inclusion into buoyancy calculations, draft prediction in vessel design is improved. Also, improvement is achieved in vessel weight estimation related to measured drafts.

"SPACE JOINT" is a new constructional element for synchronous fastening of crossover rods in and/or on space joint body. At the same time the space joint represents a fastening node within grid structure. On basis of invention "SPACE JOINT" published under the Patent Cooperation Treaty (PCT), with International Publication Number W 97/38229, (Čalić 1997) research of mechanical properties have been performed. this paper is a presentation of research dealing with rods fastening in the subject space joint body, which is achieved through friction force. Developed computer model for one space joint type is described. Computer modeling was performed on basis of finite element method. Special attention are pointed out regarding contact pressures, deformations, as well as stresses. Preliminary testing on small reinforced polyamide type space joint body was performed and preparation for testing procedures of different types from various materials and of differing dimensions have been performed. Application possibilities to various fields were suggested. In this paper usage of space joints in grid structures is described under name of "CROCKA" building, partitioning and adjusting system.

Promatrajući problematiku građenja različitih konstrukcija, posebice onih s rastavljivim spojevima u čvorovima rešetki, autor je uočio mogućnosti za poboljšanjem postojećeg stanja. Izvršio je analizu mogućih potencijalnih rješenja i prijavio izum pod nazivom PROSTORNA SPOJNICA, u okviru kojeg je prijavljeno deset tipova rastavljivog spajanja u čvorištima rešetki, uz zadržavanje jedinstva izuma. Paralelno sa postupkom zaštite u RH i pokretanjem međunarodne zaštite preko PCT-a, te pojedinačne zaštite po određenim zemljama, autor je realizirao jedan tip spojnice, manje dimenzije iz ojačanog poliamida (ili sl. materijala). Do danas su stvoreni gotovo svi relevantni preduvjeti za marketing razvijene spojnice uključujući i nuđenje paketa (spojnice, štapovi i paneli). Na Tehničkom fakultetu Sveučilišta u Rijeci pripremljen je opći kompjutorski model za analizu deformacija, odnosno naprezanja, na osnovu kojeg se mogu vrlo brzo simulirati stanja u spojevima raznih tipova, materijala i veličina. U tijeku predavanja autor će se osvrnuti na osnovna rješenja, problematiku prijavljivanja izuma u nas i u svijetu. Nadalje, u radu će se autor osvrnuti na probleme financijske prirode, izradu alata i prototipova, konačnih alata, proizvodnju i marketing proizvoda. Na kraju autor će iznijeti svoja zapažanja glede cjelokupne problematike izumiteljstva, te se osvrnuti na ulogu posebice domaće znanosti u promicanju i ostvarivanju znakovitije uloge u gospodarstvu RH kroz razne vidove intelektualnog vlasništva. Autor će svoje predavanje zaključiti s informacijama o njegovim daljnjih akcijama i prioritetima.

Application possibilities of "AntiPollutant" software in long solar pipings/chanals ......

Iskorištavanju podmorja u turističke svrhe mogu posebno doprinijeti suvremeni podmorski sustavi - podmorski parkovi. Radi se o iznimno skupim sustavima, ali i iznimno izazovnim za znanstvenike, projektante, dizajnere, turističke radnike, gospodarstvenike, bankare i graditelje.

Pomorske konstrukcije su......

U ovom je radu dan pregled potencijalnih stanja spremnika odnosno pojedinih tankova spremnika, a uvjetovanih posljedicama različitih nezgoda na plovnim putovima. Izvršena je detaljnija analiza opasnosti od polutantnih fluida, djelomično ili potpuno zarobljenih u tankovima potopljenog spremnika. Uzimajući u obzir promjenu fizikalnih osobina polutantnog i okolišnog fluida, te okolišnih uvjeta (morske struje i temperatura okolišne vode) postavljen je opći fizikalno-matematicki model za pretakanje fluida direktno na površinu, ili indirektno, u posebni potopljeni spremnik. Posebno su obradene metode pretakanja fluida primjenom specijalnih autonomnih sustava. Na osnovu postavljenog matematičkog modela za pretakanje fluida izrađen je kompjutorski program za proračun potrebne snage za pretakanje fluida. Primjenom originalnog softwarea "AntiPollutant" omogućen je racionalan izbor varijante intervencije i izbor odgovarajucih sredstava, a u cilju brze, sigurne i ekološki prihvatljive intervencije na spremnicima sa potpuno ili djelomično zarobljenim polutantnim fluidima. Za potrebe brojnih proračuna izvršena je opsežna analiza primjene raznih metoda aproksimacije, interpolacije i provlaćenja krivulja, kako za obradu ulaznih tabelarnih podataka, tako i za međurezultate proračuna i konačno za prikaz i usporedbu rezultata. Na kraju su dane sugestije za daljnja istraživanja i razvoj u ovom vrlo specificnom podrucju.

Izradom preliminarnog projekta gliserskog plovila pod nazivom "Griffon 26" namijenjenog za sportski ribolov provedena je analiza utjecaja parametara forme na hidrodinamičke značajke poluistisninskih i gliserskih plovila. Pokušale su se odrediti značajke odnosno parametri koji karakteriziraju poluistisninske odnosno gliserske tipove plovila sa stajališta hidrodinamike u mirnoj vodi. Posebna se pozornost posvetila utjecaju kuta poprečnog nagiba dna, oblika rebara i uzdužnih presjeka, mase i položaja težišta masa, te položaju i veličini brizgobrana na hidrodinamiku odnosno stvaranje hidrodinamičkih sila. Usvojena saznanja su zatim primijenjena u slijedećim krugovima projektne spirale navedenog projekta u svrhu dobivanja povoljnijih hidrodinamičkih značajki.

Dobivanje organizacije Svjetskog prvenstva u jedrenju za klasu IMS600 u Cresu za 2004. godinu potaknulo je izradu projekta regatnog krstaša za navedenu klasu koja bi konkurirala u prvenstvu. Autori su pristupili analizi pravilnika klase ; Analizi utjecaja pojedinih značajki jedrilice na IMS premjer uz stručnu pomoć Zorana Grubiše, dipl. ing. brodogradnje, predsjednika Vijeća premjerača pri Hrvatskom jedriličarskom savezu, te uz pomoć jedinstvenog IMS softvera. Nadalje izvršena je detaljna analiza potencijalnih konkurentnih brodova posljednje generacije. Kao rezultat dobiven je projekt jedrilice koja prema svojim karakteristikama ima sve predispozicije da bude brža od analizirane konkurencije, a istovremeno je postignuto da od strane IMS premjera bude prepoznata kao sporija. U ovom radu autori su prikazali kako pojedine značajke jedrilice mogu bitno utjecati na odnos realne brzine jedrilice i premjera koji je vrijedio za jedriličarsku sezonu 2003./2004.

U radu se daje kratki pregled postojećeg stanja u području hidrodinamike malih plovnih objekata. Naznačene su osnovne značajke istisninskih, poluistisninskih i gliserskih plovila kao i mogući problemi te načini za njihovo rješavanje radi postizavanja boljih hidrodinamičkih svojstava. Projektanti i proizvođači malih plovnih objekata bi trebali potražiti putove za veće korištenje teorijskih i eksperimentalnih metoda koje su danas na raspolaganju za rješavanje hidrodinamičkih problema otpora, propulzije, upravljivosti i pomorstvenosti radi postizanja optimalnih svojstava malih plovnih objekata.

Istraživanje podmorskih resursa stvara prodor u sve veće morske dubine. Postignoća na tom području u zadnjoj dekadi dosežu dubine i do 2300 m. Nove tehnologije i izgradnja novih objekata prilagođenih velikim dubinama vezani su za skupe investicije. Posljedica tog stanja je primjena postojećih pomorskih objekata u uvjetima koji prelaze njihova ograničenja. Članak opisuje model sidrenog sustava na temelju kojeg je izvršena procjena mogućnosti korištenja jedne poluuronjive platforme starije generacije, na dubini mora iznad njenih izvornih projektnih granica. Krutost, kao osnovna značajka sidrenog sustava platforme, analizirana je pomoću analitičkog modela kompozitne lanačanice sastavljene od čeličnog lanca, elastičnog užeta i koncentrirane sile na njihovu spoju. Model odziva platforme sadržavao je stacionarni dio kao i dinamičke odzive prvog i drugog reda valne frekvencije.

Doplov ophodnih brodova, tijekom projektiranja, obično se određuje na temelju otpora za srednju istisninu. Točnost određivanja doplova može se povećati već u ranoj fazi projektiranja, ako se uzme u obzir promjena istisnine usljed utroška goriva. U tu svrhu definiran je matematički model i razvijen program za osobno računalo. Za ophodne brodove forme SKLAD, istisnine 150 do 350 tona, nađene su razlike između doplova za srednju istisninu i doplova određenih za promjenjivu istisninu od –4.32% do +1.64%.

Rad obrađuje dinamiku ponašanja brodskog skladišnog prostora za čuvanje hlađenih i smrznutih namirnica. Analiza je provedena metodologijom sustavnog dinamičkog modeliranja, kao jednog od najprikladnijih i najučikovitijih načina dinamičkog modeliranja složenih nečinearnih prirodnih, organizacijskih i tehničkih sustava. Postavljen je matematički model rashladne komore, kao elementa rashladnog postrojenja, uzimajući u obzir tipične dobitke topline, temperaturu skladištenog predmeta i željenu temperaturu hlađenja. Na temelju matematičkog modela izrađen je kontinuirani računalni simulacijski model uporabom programskog jezika POWERSIM. Rezultati simulacije, za različito postavljne scenarije prikazani su grafički. Svrha rada je prikazati djelotvornost i višestruku primjenjivost postavljenog modela za: 1.) znanstvena istraživanja dinamike ponašanja rashladne komore u fazi projektiranja, ispitivanje i eksploatacije ; 2.) edukativno trenažiranje studenata i inžinjera ; 3.) ekspertnu primjenu simulacije analognih nelinearnih složenih dinamičkih sustava ; 4.) kompletiranje globalnog sustava dinamičkog modela "broda budućnosti".

A referent model is used in autopilot design nowadays, where the parameters of the model are identified. Such model is not adjusted for a single particular ship. Introduction of self-learning neural networks enables individual approach to every ship and design of the best possible control for the particular ship. The basic mathematic and algorithms are discussed. Two types of neural networks are considered: feed-foreward networks (where neurons are organised in layers and typical application is in the non-linear static mapping) and recurrent network (where the output of neurons are fed back to the inputs of some neurons. These networks are used in non-linear dynamic systems). Wavelets' role in ships' identification is considered, as well as the wavelet networks' role, as the type of the neural networks. This article presents a general idea of wavelet and neural network application in ship's identification and modelling, as well as the possible usage of wavelets aboard ships.

Zagađivanje zraka ugrožava opstanak čovječanstva na Zemlji, ne priznajući pri tome međudržavne granice. Stoga je, nakon pet godina opširne rasprave na Povjerenstvu za zaštitu pomorskog okoliša (MEPC), u rujnu 1997. usvojen dodatak VI konvenciji MARPOL 73/78, koji obrađuje sprečavanje zagađivanja zraka s brodova. Kako je ocijenjeno da su najznačajniji uzrok zagađenju zraka s brodova ispušni plinovi brodskih dizel motora, a osobito dušični oksidi sadržani u njima, u usvojenom dodatku VI posebno je obrađen NOx tehnički kodeks. Dodatak VI još nije stupio na snagu, ali će se nakon stupanja na snagu, primjenjivati retroaktivno na svaki dizel motor snage iznad 130 kW, koji bude ugrađen na brod u međunarodnoj plovidbi građen nakon 1. siječnja 2000. god. Svrha je ovog rada pravovremeno upoznati domaće brodovlasnike i brodograditelje sa osnovnim zahtjevima dodatka VI, kriterijima prihvatljivosti, te sustavom pregleda i potvrda, koje će klasifikacijski zavodi, razraditi i primjenjivati nakon stupanja na snagu dodatka VI. Budući da se za motor prije ugradnje na brod i za sam brod predviđa zaseban sustav potvrđivanja, u radu se daju smjernice za postupak u pojedinom slučaju. Mnogi se svjetski stručnjaci slažu da je NOx tehnički kodeks jedna od najzahtjevnijih i najsloženijih međunarodnih tehničkih normi uopće, tako da njegova primjena zahtijeva vrlo ozbiljan pristup.

Kako je brodograđevni proizvodni proces veoma složeni poslovno - proizvodni sustav, važnost kvalitetnog upravljanja i njegove logističke podrške od iznimnog su značaja za postizanje poslovne uspješnosti. Ovo tim više što je brodograđevni proces isprekidan (diskontinuiran) jednako i u pripremnoj i u proizvodnoj etapi, s velikim brojem tijekova materijala i informacija. U cilju smanjenja vremena gradnje i zaliha na skladištu (nedovršena proizvodnja), odnosno smanjenja ukupnih troškova gradnje, danas su u svijetu prisutna intenzivna istraživanja u pravcu razvitka suvremenih metoda upravljanja i logistike brodograđevnog procesa. U radu je prikazano postojeće stanje na ovom planu u hrvatskom brodogradilištima, ali i svjetski trendovi, koji bi se morali, uz stanovite prilagodbe, primjenjivati u našim brodogradilištima, u svrhu konkurentnosti i poslovne uspješnosti, te je predložen mogući model sustava upravljanja za hrvatska brodogradilišta.

The natural factor method is suggested for structural analysis of marine structures. The basic idea of the method as well as its advantages are presented. The method is compared with finite element method. The accuracy and sensitivity analysis has proved that natural factor approach is more robust and reliable than finite element method. It is important to emphasize that both methods need equal structure of input data so they can be run over same input file. Algorithmic option in natural factor solving based on RT decomposition is discussed too. A simple illustrative example is supplied.

Opisan je vjerojatnosni postupak proračuna ukupnog naprezanja u dijelu konstrukcije trupa jednog tipičnog broda za prijevoz spremnika. Postupak se osniva na dinamičkim značajkama broda i valnog spektra projektnog stanja mora, prema uvjetima i području korištenja broda. Dinamičke značajke odziva broda na harmonijskim valovima korištene su u obliku prijenosnih funkcija i amplitudnih operatora odziva njihanja i valnog opterećenja – tlakova, poprečnih sila i momenta savijanja. Slučajni proces ukupnog naprezanja u odabranoj točki brodske konstrukcije modeliran je superpozicijom procesa komponenti naprezanja uslijed valnog momenta savijanja M(t), valne poprečne sile N(t) i valnih tlakova p(t). Vjerojatnosne karakteristike odziva rezultirajućeg procesa proračunate su pomoću uzajamno korelacijskih funkcija i odzivnih spektara određenih na temelju dinamičkih značajki pojedinih komponenti i efektivnog valnog spektra projektnog stanja mora. Postupak je ilustriran na primjeru proračuna ukupnog naprezanja karakterističnog dijela vanjske oplate na glavnom rebru broda S175 za prijevoz spremnika. Sinteza globalnih i lokalnih komponenti procesa naprezanja konstrukcije dvodna, izvedena je primjenom metode konačnih elemenata. Za određeno projektno stanje mora prikazana je kratkoročna prognoza ekstremnih odziva ukupnog naprezanja na odabranom dijelu konstrukcije.

Zakonitost teorije pomorstvenosti intuitivn su se primjenjivale pri projektiranju i gradnji brodica tradicionalnih formi. Interesantno je analizirati domete intuitivno primjenjenih zakonitosti teorije pomorstvenosti. U tu svrhu za dvije tradiconalne i za dvije suvremene forme hrvatskih brodica izračunati su odzivi na valovima Jadranskog mora definiranog Tabainovim spektrom. Uspoređeni su i analizirani brojevi zalijevanja i udaranja u jednom satu za razmatrane brodice. Analiza vrijednosti razmatranih odziva pokazala je vrlo dobro intuitivno

Sea pollution by oil and their derivatives due to effluents released from tankers is presented. International rules and conventions review, which proscribes monitoring of releasing polluted effluents from tankers, is given. In particular, relevant national regulations imposed by Croatian authorities are presented. The need to monitor and control of releasing polluted effluents to seawater, regarding allowed concentrations of oil within fluids against stated regulations, is underlined. Conditions for controlled releasing of polluted effluents from tankers are analysed. Description of the equipment, which form the system for monitoring, and managing of effluents releasing, is presented. Improvement of that system is proposed by fitting such equipment as to enable application of two here-elaborated procedures. These procedures aim for determination of type and degree of fluid pollution, regarding pollution from the oily waters from ship systems, and from metal elements harmful or toxic for sea ecosystem.

The installation of submarine cables on the seabed is becoming of significant importance because of rapidly increasing expansion of telecommunication systems. One of the components for efficient cable laying operation requires the avoiding of high dynamic tensions that can have detrimental effects. A numerical approach for predicting motion and tension of marine cables during laying operations in a rough sea is presented. Illustrative applications of the method are given for a cable-lying ship of approximately 100 m length, designed to properly install and repair submarine cable systems. The results are presented as transfer function and response spectrum of cable dynamic tension for two different types of cable and several heading angles. The obtained responses make possible to determine order statistics of the cable lying process.

Ljuljanje broda tijekom boravka na moru može značajno narušavati učinkovitost pojedinih radnji na brodu. Suvremeni putnički brodovi, kao i ratni brodovi, opremljeni su različitim sustavima za stabilizaciju ljuljanja, koji povećavaju ugodnost putnika, te značajno unapređuju raspoloživost ostalih sustava ratnog broda. Mada je kormilo namijenjeno prije svega za održanje kursa broda, ono je u stanju proizvesti i moment koji proizvodi ljuljanje broda. Ovaj učinak koristi se za stabilizaciju. Primjena kormila za stabilizaciju ljuljanja broda pogodna je i iz razloga što su ovakva rješenja značajno jeftinija nego drugi sustavi ove namjene. U radu je dan jedan relativno složeni matematički model ponašanja broda na valovlju. Projekt linearnog regulatora je zasnovan na optimalnom ograničenom kovarijansnom upravljanju, tj. zadane su gornje granice odredenih kovarijansi stanja sustava sa regulatorom. Regulator je projektiran uz uvjet minimuma ulazne energije.

Poznato je da svojstva kompozita ovise ponjprije o sastavu i građi komponenata (matrica, ojačalo), ali i o načinu njihova međusobna povezivanja (adhezija, međuslojevi, međupovršine), te o postupku izrade (pojava šupljina). Za procjenu ponašanja kompozita u realnim uvjetima naročito su važne pojave u međuslojevima odnosno međupovršinama, jer je upravo raslojavanje ili delaminacija matrice i ojačala ili pojedinih slojeva ojačala jedan od najčešćih uzroka promjene svojstava kompozita. Zato je međuslojna čvrstoća važna karakteristika kompozita koja ima odlučujući, iako često zanemareni utjecaj na trajnost takvih konstrukcijskih dijelova. U radu su prikazani rezultati određivanja međuslojne čvrstoće kompozita na bazi poliesterske smole s dva različita tipa staklenog ojačanja s osvrtom na oblike oštećivanja, te utjecaj šupljina i medija.

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