An affecting on the port bottom by ships water jet during berthing manoeuvre

In port engineering in the vicinity of quays, the action of the ship's propulsion is a prime eroding element. This may cause scouring of the bottom of port water area and erosion so great that it could lead to ąuay damage by change of its stability. Thus, the speed of ship's water jet is important criterion of navigational safety assessment. Scouring of an unprotected bottom depends on the type of manoeuvres (ship's settings and their duration), area depth and type of bottom. As the number of cruise ships, irregularly calling at ports, has increased recently, there is often a need to accept such ships for berthing along quays with an unprotected bottom. Bottom protection is a costly investment, far from profitable when callings are not frequent. The situation when a ship gives up its own propulsion during berthing and unberthing and has to use tugs is not profitable for ship operators. As a result, ships may resign from calling at such ports. For this reason it is purposeful to make a navigational analysis [1] of ship manoeuvring near the ąuay and to assess the effect of water jet on the bottom. This paper examines large ships manoeuvres during berthing. The study focuses on analytical methods for assessing ship 's affect on the port bottom. The paper presents some problems on possible manoeuvres of cruise ships with own propulsion along the Bulwar Chrobrego Quay in the port of Szczecin.