The development of the transport sector is faced with increasing demand, simultaneously concerning quality and quantity. More passengers have to be carried on the existing network with a reliable quality of service at lower cost. However, the sensitivity of the railway system rises as the capacity utilisation increases. The traffic performance and the quality of transport service are therefore closely connected and some specific characteristic values provide a scientific description of this correlation. The carrying capacity of a line is one of these characteristic values. It describes the number of trains that can travel a track section in a defined time period with precise qualitative conditions. This Master Thesis looks at increasing capacity on railway lines. On most European routes, there is a classic operation with fixed intervals. The headway time of the trains is given by the division of the track into blocks. The length of the blocks is delimited by fixed block signalling. Fixed block signalling provides safety and regulation in stations and on the railway line. Therefore, there is a question regarding the extent to which the division of block sections is a parameter in influencing the carrying capacity. As a first step, the research question will be clearly defined. Then the definition and the methodology to determine the capacity of a railway line will be explained. In the second part, the basic principles of performance analysis will be specified. The focus is on running dynamic properties, regulation and safety of spacing trains, and relevant influencing factors on capacity. In the next step, an experimental determination of the capacity gain caused by a diminution of the block length will be executed. Approximation methods will be described and a simulation to evaluate the influence of the division of block sections will be executed. The result of the Master Thesis is a program in which all relevant parameters, for instance the technical condition of the train (acceleration and braking capacities, length...), the speed of the trains and the block division, can be modified. The simulation output is a representation of the blocking time stairway into a time-over-distance diagram. The effects of an optimized block division on the carrying capacity will be subsequently analysed.