The Port of Klaipėda is Lithuania’s only ice-free port and one of the most important transport hubs in the Eastern Baltic region. Every day, vessels of various types – from passenger and cargo ships to tankers – navigate its waters, making safe vessel traffic one of the port’s key priorities. Heavy maritime traffic, narrower sections of the channel and large vessels moored alongside the quays present challenges for navigation specialists that require not only knowledge and experience, but also advanced technologies.
Kamilija Būdvytytė, a graduate of the Marine Navigation study programme, dedicated her bachelor’s thesis to exploring this topic. She was awarded a scholarship by the Klaipėda Industrialists’ Association for research of significance to the city of Klaipėda. In her thesis, „Analysis of the Safe Passing of Vessels with Moored Ships in the Port of Klaipėda Based on the Recommendations and Regulations of International and Local Institutions“, she examined how the speed of a passing vessel and its distance from a moored vessel affect navigational safety.
Using an advanced navigation simulator and digital modelling, K. Būdvytytė analysed various vessel-passing scenarios and assessed their impact on mooring systems and overall safety. The research results revealed that even relatively small changes in speed or distance can have a significant effect on the safety of vessel traffic and can help facilitate more effective decisions when organising traffic in the Port of Klaipėda.
Although it may seem that the greatest risk is faced by moving vessels, according to the VILNIUS TECH graduate, moored vessels are also exposed to hazards. A passing vessel generates waves, water currents and pressure changes that can affect a moored vessel. These hydrodynamic effects can cause a vessel to be drawn towards the passing ship or pushed away from the quay, placing additional loads on mooring lines and quay fenders. Such situations are particularly sensitive when tankers are moored alongside the quay.
„During my research, I paid particular attention to the factors that determine the safe passing of vessels. Some of the most important are vessel speed, the distance between vessels, their size and draught, as well as the width and depth of the channel. Weather conditions are equally important, including wind, currents and visibility. The main principle is simple: the higher the vessel’s speed, the greater the safe distance from a vessel moored alongside the quay should be,“ says K. Būdvytytė.
To assess the impact of these factors, she used modern technologies. The research was conducted using the Wärtsilä TRANSAS NTPro 6 navigation simulator, in which the Port of Klaipėda channel was recreated. Different scenarios were modelled to analyse the passing of a Ro-Ro vessel alongside a tanker moored at the quay, while varying the vessel’s speed and the distance between the ships.
According to the author, digital modelling provided insights that went far beyond theoretical calculations. The simulator made it possible to assess not only hydrodynamic forces, but also the effects of wind, currents, restricted water depth and changes in manoeuvrability. Such simulations provide an opportunity to safely test a variety of scenarios that would be difficult or even dangerous to reproduce under real-life conditions.
„One of the most interesting findings of the research was that even small changes in speed or distance can significantly affect the loads on mooring lines. The highest loads were recorded not when the vessels were approaching or moving away from each other, but when they were sailing parallel to one another in close proximity. For example, when a vessel was travelling at a speed of 8 knots at a distance of just 50 metres from a tanker, the maximum load on a single mooring line reached 7.2 tonnes-force. When the speed was reduced to 4 knots or the distance increased to 120 metres, the loads decreased several times. These results clearly demonstrated that lower speeds and greater distances make a significant contribution to safety,“ explains the VILNIUS TECH graduate.
According to K. Būdvytytė, the findings of the research could be useful not only for scientific research but also for the practical operations of the Port of Klaipėda. They could help determine safe sailing speeds more precisely in different areas of the port, improve vessel traffic management procedures, and support the training of pilots and bridge teams. K. Būdvytytė also suggests considering situational speed restrictions in areas where vessels pass particularly close to tankers moored alongside the quays.
Today, safe navigation is supported by a wide range of smart technologies. Vessels use electronic navigation systems, radar, Automatic Identification Systems (AIS), electronic charts and various communication solutions. An important role in port operations is played by the Vessel Traffic Service (VTS), which monitors vessel movements in real time and coordinates their actions.
„Future ports will increasingly resemble smart transport systems. Artificial intelligence (AI), automated traffic management platforms and so-called digital twins will help predict potential risks more accurately, identify the safest routes and optimise vessel movements. Nevertheless, even as technologies continue to advance rapidly, the human factor will remain crucial – whether it is a pilot, captain or traffic management specialist who makes the final decision in critical situations,“ says K. Būdvytytė.
The research conducted by the VILNIUS TECH graduate demonstrates that modern maritime navigation is inseparable from advanced technologies, while safety still depends heavily on people’s ability to make responsible decisions. The study highlights how scientific knowledge, digital modelling and innovation can contribute to safer and more efficient port operations in the future.