Methods for determining the required number of harbour tugs using approximate dependencies in different ports of the world

Abstract

The article examines foreign norms for determining the number and carrying capacity of harbour tugs in various ports. The purpose of the study is the analysis of different approaches as well as parameters of tugs for towing operations in confined operation areas based on the size of transport vessels. The result of study is the identification of the interrelation between the size of transport vessels and the operational characteristics of harbour tugs for their processing. Options were determined for the number and capacity of harbour tugs in relation to transport vessels of the required standard sizes in accordance with foreign rules of different ports. This will potentially help to understand in which ports these requirements are closest to the requirements of mandatory regulations of the Russian Federation seaport captains. The research also allowed to conclude that a more convenient criterion for selection of a towing connection required for tugging and towing of transport vessels is not the mechanical power of its main engines, but the tractive force on the hook developed at headway movement.