A method for determining the initial velocity and range of flying fragments is proposed. Quantity-Distance (Q-D) principles are discussed and some arguments are presented for why even the observance of Q-D principles cannot prevent sympathetic explosions due to flying fragments. Example calculations are included and the results are compared to the results of an actual explosion. The results show that this method should be suitable for evaluating fragment velocity and range. Limitations of the method and proposals for possible future improvements are discussed in the conclusions. (C) 2012 American Institute of Chemical Engineers Process Saf Prog, 2012