The validated TORSIM (TORpedo SlMulation) model simulates the behaviour and determines the effectiveness of different torpedo types (MK46 and MK48), launched from a surface ship, from an air vehicle or from a submarine , against different types of submarine s or surface ships. Evasive manoeuvres of the submarine and the surface ship are included. The model simulates the kinematics and the açoustics (ALMO ST: Acoustic Loss Model for Operational Studies and Tasks) ofthe different objects. For the procurement of a torpedo defence system, the Royal Netherlands Navy has the intention to be a smart specifier and a smart buyer. A simulation environme nt for torpedo defence (Torpedo Defence System Test Bed (TDSTB)) will be developed and made available for analysis, development of tactics and assistance in procurement. The TDSTB is based on MOSES (Maritime Operations Simulation and Evaluation System). MOSES provides a hardware and software environment for the evaluation and validation of systems, concepts, and tactics in the flreld of underwater warfare. It defines standards for integration and re-use of research concepts and methods (e.g. torpedo modelling in TORSIM).