Vessels and Ballast Water - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 12

Vessels and Ballast Water

Matej David

Abstract Commercial vessels are built for the transport of various cargoes or
passengers. When a vessel is not fully laden, additional weight is required to pro-
vide for the vessel's seaworthiness, e.g. to compensate for the increased buoyancy
which can result in the lack of propeller immersion, inadequate transversal and
longitudinal inclination, and other stresses on the vessel's hull. The material used
for adding weight to the vessel is referred to as ballast. Historically, ballast material
was solid, but after the introduction of iron as basic vessel building material in the
middle of the nineteenth century, loading of water (i.e., ballast water) in cargo holds
or tanks had shown to be easier and more effi cient. Even when a vessel is fully laden
it can require ballast water operations due to a non-equal distribution of weights on
the vessel, weather and sea conditions, an approach to shallow waters, and the con-
sumption of fuel during the voyage. As a result of these factors, vessels fundamen-
tally rely on ballast water for safe operations as a function of their design and
construction. This chapter describes vessel's ballast water systems, ballast tank
designs, ballasting and deballasting processes as well as safety and legislative
aspects of ballast water operations. In addition a detailed ballast water discharge
assessment model is provided. Using concepts of this model an estimation of global
ballast water discharges from vessels engaged in the international seaborne trade
was estimated as 3.1 billion tonnes in 2013.

Keywords Ballast water ￿ Vessels design ￿ Ballast water system ￿ Ballast water
tank design ￿ Ballasting and deballasting processes ￿ Ballast water safety and legis-
lative aspects ￿ Ballast water discharge assessment