This chapter deals with loads related to the hull structure, the operation of mechanical equipment as well as those related to cargoes. The loads related to the hull structure include hull weight, inertial loads, loads induced during the fabrication process (residual stresses) as well as loads acting during occasional circumstances. These include drydocking, launching, and conversion procedures. Grounding and collision that are undesirable events are also discussed. Loads that are induced by the operation of mechanical equipment are considered, the most important of these being propeller-induced vibration and vibration of the main propulsion machinery. Cargo-induced loads are discussed next. These relate to both cargo and ballast water and include weight, inertial loads and the effect of cargo shifting. Lastly thermal gradients are considered the most important cases being the heating of crude oil using heating coils and ensuring low temperature in the case of gas carriers. The loads acting on the hull girder are summarised in tabular form in which their relative importance is assessed. In the last section load action is described with the principal loads acting on the hull girder discussed as well as the different load systems (primary, secondary and tertiary).