Seismic response of liquid storage tank can be strongly influenced by the presence of submerged components. This modification of the dynamic characteristics of the liquid tank systems with internal components can be very useful for improving their seismic behavior. In this paper, a pressure-based finite element technique has been developed to analyze the slosh dynamics of a partially filled rigid container with bottom-mounted submerged components. The fluid is assumed homogeneous, isotropic, inviscid, and to exhibit only limited compressibility. The problem is linearized assuming the frequency of the exciting oscillation not in the immediate neighborhood of the natural slosh frequency, so that the slope of the free surface is small. The linearized problem is spatially discretized using the Galerkin weighted residual method. Earthquake excitations are used as the prescribed boundary condition. The solution is advanced in time using Newmark's constant average acceleration method. The developed code has been used to investigate the effect of a bottom-mounted rectangular component on the slosh dynamics of a liquid-filled rigid container. Numerical results obtained are compared with the existing solutions to validate the code. The parametric study of the tank-fluid system shows the importance of height, width and location of the submerged structural components. © 2007 Elsevier Ltd. All rights reserved.