Including mass of equipment
There is a feature in Sesam for fixed structures, DNV GL's FEM software, for modelling equipment as load producing objects. Both distinct objects (tanks, generators, etc.) and blanket loads representing live and other loads are best modelled using this equipment feature.
While the equipment yield line loads for a static analysis they must be represented as masses in a dynamic analysis. This is done by selecting the equipment to be represented as mass instead of as line loads. This involves that mass points are created at appropriate nodes when creating a FE mesh.