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Bearing wear of connecting rod and crankshaft of a two-stroke slow-revving internal combustion engine
No full textU radu su u osnovnim crtama opisane ojnica i koljeničasto vratilo, dvije komponente motora.
Opisana je njihova uloga te osnovne konstrukcijske izvedbe i materijali od kojih su građeni.
Također, klizni ležajevi, sustavi njihova nadziranja potrošnje i načini njihova podmazivanja u
ovom su radu spomenuti radi lakšeg razumijevanja trošenja. Kao uvod u glavnu temu
objašnjen je i proces trenja koji dovodi do samog trošenja. Mehanizmi trošenja potkrijepljeni
su fotografijama materijala na koje su ti mehanizmi djelovali. Spominju se i načini na koje se
trošenje može smanjiti do određene mjere. Navedeni su načini eksperimentalnog određivanja
kompatibilnosti pojedinih materijala za rad u sustavu međusobnog klizanja. Cilj ovog rada je
pobliže objasniti načine trošenja u ležajevima ojnice i koljeničaste osovine koji se događaju
prilikom rada motora.The paper basically describes the connecting rod and crankshaft, two components of the
engine. Their role is described, as well as the basic construction performance and materials
from which they are built. Also, sliding bearings, their wear monitoring systems and their
lubrication methods are mentioned in this paper for easier understanding of wear. As an
introduction to the main topic, the friction process that leads to wear itself is explained. The
mechanisms of wear are supported by photographs of the materials on which these
mechanisms acted. Ways in which wear can be reduced to a certain extent are also
mentioned. Methods of experimentally determining the compatibility of individual materials
for working in a mutual sliding system are listed. The aim of this paper is to explain in more
detail the ways of wear in connecting rod and crankshaft bearings that occur during engine
operation
Shipping of the eastern Adriatic between two wars (World War II and Croatian War of Independence)
No full textPomorsko brodarstvo na istočnom Jadranu između Drugog svjetskog rata i
Domovinskog rata imalo je značajnu ulogu kao ključna gospodarska i društvena sila. Analiza
arhivske građe, poslovnih dokumenata i poslovanja omogućuje dublji uvid u aktivnosti,
djelovanje i flotu najznačajnijih brodara toga vremena. Poseban fokus se stavlja na trgovačku
mornaricu bivše Socijalističke federativne republike Jugoslavije, koja je bila glavni predstavnik
brodara istočne obale Jadrana. Ovim istraživanjem želi se osvijetliti važnost pomorskog
brodarstva u oblikovanju gospodarskih i društvenih aspekata na istočnom Jadranu u tom
razdoblju te pridonijeti širem razumijevanju povijesne uloge pomorske industrije na tom
području.Maritime shipping in the Eastern Adriatic between the Second World War and the
Croatian War of independence played a significant role as a key economic and social force. The
analysis of archival records, business documents, and operations provides a deeper insight into
the activities, operations, and fleets of the most prominent shipowners of that time. Special
attention is given to the merchant navy of the former Socialist federal republic of Yugoslavia,
which served as the primary representative of shipowners on the eastern coast of the Adriatic.
This research aims to shed light on the importance of maritime shipping in shaping the
economic and social aspects in the Eastern Adriatic during that period and contribute to a
broader understanding of the historical role of the maritime industry in the region
Automatic traffic management
No full textU suvremenom svijetu, automatizacija i autonomno upravljanje postaju ključni čimbenici u raznim sektorima, uključujući promet. Pametni i automatizirani prijevoz, zajedno s pametnim upravljanjem gradskim prometom, transformiraju način rješavanja
suvremenih prometnih izazova. Ova rješenja, potkrijepljena suvremenom tehnologijom poput umjetne inteligencije, senzora i brzih komunikacijskih tehnologija, smanjuju zagušenja na gradskim cestama i poboljšavaju mobilnost. Uz brz razvoj telekomunikacija, uključujući IoT uređaje i 5G mreže, stvaraju se temelji za učinkovito upravljanje transportom u stvarnom vremenu. Automatsko upravljanje u prometu već je stvarnost u mnogim gradovima, a njihova iskustva koriste se za unaprjeđenje sustava na novim lokacijama. Budući razvoj ovih tehnologija zahtijevat će suradnju između akademskih institucija, poslovnog i privatnog sektora te vlasti kako bi se osiguralo uspješno implementiranje u urbanim okruženjima. Rad istražuje ključne trendove i perspektive automatskog upravljanja u prometu s ciljem oblikovanja boljih prometnih sustava. Upravljanje u prometu, s naglaskom na automatizaciju i autonomno upravljanje, postavlja se kao osnovna tema istraživanja. U ovom se radu analiziraju tehnološke inovacije i koncepti koji oblikuju promet u 21. stoljeću, uključujući različite prometne sektore i primjenu naprednih tehnologija. Pri tome se temeljem iskustva različitih primjera, analize suvremene tehnologije i razvojnih potencijala nastoji napraviti pregled trenutnih mogućnosti i primjena automatiziranih sustava za upravljanje u prometu te prepoznati tendencije budućeg razvoja automatskog upravljanja u prometu. S obzirom na potencijalne prednosti u ekonomskoj efikasnosti, smanjenju onečišćenja i unaprjeđenju mobilnosti, automatsko upravljanje u prometu ostaje ključnim područjem istraživanja i razvoja u budućnosti.In the modern world, automation and autonomous control are becoming key factors in various sectors, including transportation. Smart and automated transportation, along with smart urban traffic management, are transforming how we address contemporary traffic challenges. These solutions, supported by advanced technologies such as artificial intelligence, sensors, and high-speed communication technologies, reduce congestion on urban roads and enhance mobility. With the rapid development of telecommunications, including IoT devices and 5G networks, the foundation is being laid for efficient real-time transport management. Automated traffic management is already a reality in many cities, and their experiences are being used to improve systems in new locations. The future development of these technologies will require collaboration between academic institutions, industry, and government authorities to ensure successful implementation in urban environments. This paper explores key trends and perspectives in automated traffic management with the aim of shaping better transportation systems. The issue of traffic management, with a focus on automation and autonomous control, is the central theme of this research. This paper encompasses technological innovations and concepts that shape transportation in the 21st century, including various transportation sectors and the application of advanced technologies. Based on the experiences of different examples, analysis of contemporary technology, and developmental potential, an overview of current possibilities and applications of automated traffic management systems is attempted, while also identifying trends in the future development of automated traffic management. Given the potential benefits in economic efficiency, pollution reduction, and mobility enhancement, automated traffic management remains a key area of research and development in the future
Quantitative Analysis of Fuel Consumption and Fuel Sediments Separation as a Function of Fuel Type and Ship Operation Mode on Product/Chemical Tanker Example
No full textFuel consumption onboard is influenced on several factors but most crucial is ship operation mode and fuel type in use. Conventual fuel preparation process onboard consists of several stages. One of the most essential processes is centrifugal separation treatment operation onboard, which consists of introducing fuel into the field of high centrifugal field, where impurities and sediments are separated from fuels. The quantity of separated sediments and impurities from the fuel is essential for accurate calculating the remaining fuel quantity on board (ROB). The purpose of this paper is to determine and verify the influence of potential factors that can affect the quantity of fuel consumption and separated sediments quantity from the fuel based on actual data from real product/chemical tanker powered by conventional fuels. By means of statistical analysis the average values, minimums, maximums, standard deviations, and variations, median and modes, standard errors for separated sludge from fuel, heavy fuel consumption (HSHFO) and diesel fuel consumption (LSMGO) during entire observed period and during specific operations modes are obtained. Furthermore, regression formulas between separated sediments from fuel vs fuel consumption during each ship operation mode are generated. Finally, by means of single and multifactorial analysis significant influence of ship operations mode on fuel consumption and separated quantity has been confirmed. This research contributed to find relations more accurately between separated sediments quantity to fuel consumption that might be used for more accurate emission calculation
Traffic Microsimulation of the Main Junction Connecting the Urban Road Network with the Sea-Port Container Terminal
No full textEfficient transportation connectivity between ports and the hinterland is essential for the functioning of the port, especially for container terminals that predominantly rely on road transport. The integration of port and urban traffic flows, particularly in terminals located near cities, has a double impact on the level of service of urban traffic and the efficiency of the port. This paper examines the effects of a newly built container terminal, with a capacity of less than 1 million TEU per year, on urban traffic in Rijeka, Croatia. A microscopic-level simulation method is used together with traffic network modeling design. The research identifies potential bottlenecks or critical elements in the network with lower performance for the current traffic demand and the future growth scenarios of the container traffic. The study’s findings contribute to understanding the dynamic characteristics of port and urban traffic flow correlation, crucial for efficient transportation management and sustainable urban development in port cities
Internal on-board communication systems
No full textInterna komunikacija na brodu odnosi se na komunikacijske sustave i protokole koje koriste posada i časnici za međusobnu komunikaciju dok su na brodu u slučaju potrebe. To može uključivati verbalnu i pisanu komunikaciju, kao i razne oblike digitalne komunikacije. Postoje različite vrste sustava koji su ključni kako bi se osigurao učinkoviti i siguran rad broda, a koriste se za razne svrhe kao što su prosljeđivanje i izdavanje naredbi, prijavljivanje problema te pravovremene reakcije u slučaju nužde kako bi se spriječile veće štete ili izbjegle moguće nepravilnosti u sustavu.Internal on-board communication refers to communication systems and protocols used by crew and officers to communicate with each other while on board in case of need. This may include verbal and written communication, as well as various forms of digital communication. There are different system gardens that are essential to ensure the efficient and safe operation of the ship and are used for various purposes such as forwarding and ordering, reporting problems, and timely emergency reactions to prevent major damage or to avoid possible system irregularities
Quantitative Analysis of Fuel Consumption and Fuel Sediments Separation as a Function of Fuel Type and Ship Operation Mode on Product/Chemical Tanker Example
No full textFuel consumption onboard is influenced on several factors but most crucial is ship operation mode and fuel type in use. Conventual fuel preparation process onboard consists of several stages. One of the most essential processes is centrifugal separation treatment operation onboard, which consists of introducing fuel into the field of high centrifugal field, where impurities and sediments are separated from fuels. The quantity of separated sediments and impurities from the fuel is essential for accurate calculating the remaining fuel quantity on board (ROB). The purpose of this paper is to determine and verify the influence of potential factors that can affect the quantity of fuel consumption and separated sediments quantity from the fuel based on actual data from real product/chemical tanker powered by conventional fuels. By means of statistical analysis the average values, minimums, maximums, standard deviations, and variations, median and modes, standard errors for separated sludge from fuel, heavy fuel consumption (HSHFO) and diesel fuel consumption (LSMGO) during entire observed period and during specific operations modes are obtained. Furthermore, regression formulas between separated sediments from fuel vs fuel consumption during each ship operation mode are generated. Finally, by means of single and multifactorial analysis significant influence of ship operations mode on fuel consumption and separated quantity has been confirmed. This research contributed to find relations more accurately between separated sediments quantity to fuel consumption that might be used for more accurate emission calculation
Maintenance of the electrical power system on the passenger ship Norwegian Gem
No full textPutnički brodovi predstavljaju kompleksne tehničke sustave koji omogućavaju udobno putovanje i boravak putnika diljem svijeta. Održavanje optimalne funkcionalnosti i sigurnosti tih brodova zahtijeva visoku razinu stručnosti i pažnje. Jedan od ključnih aspekata održavanja putničkih brodova jest upravljanje električnim sustavima visokog napona koji pokreću brodske operacije i pružaju potrebne usluge putnicima. Međutim, rukovanje s visokim naponom na brodu nosi sa sobom značajne tehničke izazove i sigurnosne rizike koji zahtijevaju precizne procedure, stručnost osoblja te dosljedno poštivanje sigurnosnih standarda. U skladu s tim, ovaj diplomski rad usmjerava pažnju na dva ključna aspekta: prvo, na kompleksnost i izazove koji proizlaze iz održavanja putničkih brodova, te drugo, na važnost učinkovitih i sigurnih postupaka rukovanja uređajima visokog napona unutar brodskih električnih sustava na primjeru putničkog broda Norwegian Gem.Passenger ships represent complex technical systems that enable comfortable travel and accommodation for passengers worldwide. Maintaining optimal functionality and safety of these vessels requires a high level of expertise and attention. One of the key aspects of maintaining passenger ships is the management of high-voltage electrical systems that power maritime operations and provide essential services to passengers. However, handling high voltage onboard entails significant technical challenges and safety risks that demand precise procedures, personnel expertise, and consistent adherence to safety standards. Accordingly, this master's thesis focuses on two key aspects: firstly, the complexity and challenges arising from the maintenance of passenger ships, and secondly, the importance of effective and secure procedures for handling high-voltage equipment within Norwegian Gem shipboard electrical systems
Protective measures when working on ro-ro ship
No full textRazvojem integralnog transporta odnosno uspostavom paletizacije i kontejerizacije javlja se istovremeni razvoj multimodalnog transporta. Ovu novu tehnologiju transporta u pomorstvu obilježavaju RO-RO brodovi. Za realizaciju nisu potrebna velika ulaganja u mehanizaciju niti u terminale. Prijenosom tereta na kotačima, RO-RO brodovi čine nastavak kopnenih robnih puteva preko mora omogućavajući transport robe od proizvođača do potrošača. Na samom početku RO-RO brodovi bili su konstruirani za kraće rute, no kasnije su se opravdali i na dužim relacijama. Kombinirani RO-RO brodovi uz teret na kotačima prevoze djelomično i kontejnere u skladištima te na palubi uz mogućnost horizontalne (RO-RO) i vertikalne (LO-LO) manipulacije. Strukturu RO-RO brodova obilježava veličina te dizajn brodskih rampi shodno čemu se nameće i visoka cijena gradnje ovih brodova. Pri eksploataciji broda, rampe se koriste rijetko, što nameće potrebu ugradnje manjih i jeftinijih rampi, a sve više sredstva investira se u Link spanove na lučkim terminalima gdje se oprema koristi efikasnije.. Shodno nezgodama koje su se događale, u budućnosti će se trebati donijeti strože propise u gradnji ovih brodova. To se najviše odnosi na stabilnost broda u oštećenom stanju, na sustav pregrađivanja nepropusnim pregradama te na sprečavanje naplavljivanja. Također, Međunarodna pomorska organizacija (IMO) usvojila je u tu svrhu niz amandmana na Međunarodnu konvenciju o zaštiti života na moru (SOLAS).The development of integral transport, i.e. the establishment of palletization and containerization, leads to the simultaneous development of multimodal transport. This new shipping technology is characterized by RO-RO ships. Realization does not require large investments in mechanization or terminals. By transporting cargo on wheels, RO-RO ships form a continuation of land freight routes across the sea, enabling the transport of goods from producers to consumers. At the very beginning, RO-RO ships were designed for shorter routes, but later they justified themselves on longer routes as well. Combined RO-RO ships, in addition to cargo on wheels, partially transport containers in warehouses and on deck with the possibility of horizontal (RO-RO) and vertical (LO-LO) manipulation. The structure of RO-RO ships is characterized by the size and design of the ship's ramps, which imposes the high cost of building these ships. When operating a ship, ramps are rarely used, which necessitates the installation of smaller and cheaper ramps, and more and more funds are invested in Link spans at port terminals where the equipment is used more efficiently. According to the accidents that have occurred, in the future it will be necessary to stricter regulations in the construction of these ships. This mainly refers to the stability of the ship in a damaged state, to the system of partitioning with impermeable partitions and to the prevention of flooding. Also, the International Maritime Organization (IMO) adopted a series of amendments to the International Convention for the Safety of Life at Sea (SOLAS) for this purpose
Multimodal transport and bimodal technologies
No full textTransport u današnje vrijeme obuhvaća veliki broj razvijenih tehnologija koje su posljedica
kontinuiranog rasta i razvitka suvremenih tehnologija. Iste doprinose sigurnom, brzom i
učinkovitom radu i manipuliranju tereta. Razvojem Huckepack i bimodalne tehnologije
javljaju se prednosti poput povećane produktivnosti cestovne i željezničke infrastrukture,
suprastrukture te povezivanje cestovnog i željezničkog transporta koje se odvija bez
pretovara tereta. Nadalje, smanjuje se udio troškova transporta u cjelini te se produljuje
vijek trajanja cestovnih vozila i sukladno tome smanjuje se broj nesreća na cestama kao i
veći protok prometa preko graničnih prijelaza. S obzirom na tehničke, tehnološke,
ekonomske i organizacije nedostatke u Huckepack tehnologiji, pojavila se potreba za
maksimalnom raspodjelom tereta s jedne na drugu granu prometa, a da se istodobno osigura
siguran, brz i racionalan prijevoz tereta u kopnenom prometu. U tom kontekstu evidentna
je pojava bimodalne tehnologije koja doprinosi većoj racionalnosti i učinkovitom
upravljanju kopnenim prometom.Transport today includes a large number of developed technologies that are a consequence
of the continuous growth and development of modern technologies. The same contribute to
safe, fast and efficient work and handling of loads. With the development of Huckepack and
bimodal technology, there are advantages such as increased productivity of road and rail
infrastructure, superstructure, and the connection of road and rail transport that takes place
without transshipment of cargo. Furthermore, the share of transport costs as a whole is
reduced and the service life of road vehicles is extended, and accordingly the number of
accidents on the roads is reduced as well as the greater flow of traffic across border
crossings. Considering the technical, technological, economic and organizational
shortcomings in Huckepack technology, there was a need for maximum distribution of cargo
from one branch of transport to another, while at the same time ensuring safe, fast and
rational transport of cargo in land transport. In this context, the appearance of bimodal
technology is evident, which contributes to greater rationality and efficient management of
land traffi