Today the usage of numerical simulation for determination of the shell growth, surface temperature and metallurgical length for a continuous casting machine is state of the art. The knowledge of the metallurgical length of a continuous casting machine is for the quality of the manufactured strand of importance. Thereby the electromagnetic stirring at the lowest point of liquid pool or the soft reduction can use efficiently. The present thesis uses the example of a round strand continuous casting machine (ESB sprl Engineering Steel Belgium) for the generally procedure of a thermal illustration of the continuous casting process. The focus of this thesis is not the description of the used numerical model, but at the verification of the calculated results (surface temperature and shell growth) with the aid of data from the process. Concerning this matter great efforts were made to measure the surface temperature of different casting dimensions (400 and 600 mm diameter) and steel grades. In further consequence wedges were rolled-in into the strand at three different roll positions. The aim of the rolling of the wedges was to initialize hot cracks and the subsequent metallographic evaluation of the position of the hot cracks in the strand. As hot cracks arise very close to the solidification front, the calculated shell growth can be verified with this experiment. The determination of the used boundary conditions for the solidification calculation will be presented at the present thesis. Calculated results will be compared and discussed with the measured data of the continuous casting machine. As the zone of direct water cooling is very short, the specific characteristic of this continuous casting machine is a cooling on the basis of heat radiation over a long range.