Aluskaluston kehitys – Aluskoon kehityksen vaikutus vesiväyliin

Abstract

<p>Over the past twenty years, the average size of vessels arriving in Finnish ports has increased for most vessel types. Especially for cruise vessels, ro-ro cargo ships and container ships, it is significant that the horizontal dimensions, i.e. length and breadth, have increased proportionally more than the draught, and this increase is expected to continue. On average, the ro-ro ships currently under construction and entering Finnish traffic are approximately 60 metres longer and 10 metres wider than the average vessels in 2001. However, their average draught is only one meter greater. This creates the need to shift the focus of channel design and channel development projects to the width and geometry of the channel in order to ensure safe and smooth transport on fairways also in the future.<br></p><p>As the vessel size has increased, the windage area of cruise vessels, ro-ro passen-ger and ro-ro cargo ships in particular has increased even further, causing more challenges for navigating narrow channels and the need to have reserve margins. Improving the geometry of the channels was prominently highlighted in the study. Steep bends need to be rounded out and the turning areas widened to ensure the safe turning of larger vessels.<br></p><p>For cost reasons, the deepening of the channel must not lead to the narrowing of the channel at the same time: on the contrary, the narrow channel sections should be widened in order to improve both safety and traffic flow. The channel sections excavated in the rock are particularly challenging due to a number of factors af-fecting the ship’s navigation. In them, reserve margins would be particularly nec-essary, as a possible collision with a rock wall can pose both a serious safety risk as well as lead to higher costs.<br>In the development of the fairways, it is recommended that the users of the chan-nels are involved in the planning already at an early stage. The importance of simulation runs is emphasised and they should be performed using channel-spe-cific design ships already at the design phase, in order to optimise channel geom-etry.<br></p><p>The state-run channel sections as well as the channel sections and port basins managed by the ports form a coherent whole, which must be in good condition in all respects in order to ensure safe and smooth traffic. In addition to up-to-date measurement data on channels and depth data per quay, accurate condition data from ports are needed to ensure the safe entry and departure of large ships.<br></p><p>The geopolitical situation in Europe, which changed in spring 2022, may lead to an increase in vessel size as the transport distances of crude oil become longer. Liq-uefied natural gas will be transported in significant quantities by sea. The situation also affects the rotation of container ships, but the longer-term impacts on the development of vessel size are still difficult to assess. Measures aimed at reducing maritime emissions may also affect vessel size, in addition to reducing the engine output of vessels.<br></p>