Surge chambers are a very important element in hydropower plant systems. Chambers have a double function, they provide a sufficent water delivery during the turbine startup process and they also absorb the energy that is made during the turbine outage in a way to prevent damage occuring after a water hammer. Water mass oscillations are created in the surge chambers after a water hammer. Some water mass oscillations can be dangerous for the engine room and the people working in it and so it is imperative to make correct assumptions about them. There are a several ways to determine water mass oscillations in the surge chambers. One way is to implement a physical model; a model of the surge chamber is made and it is then mounted on a device to conduct experiments to determine the characteristics of the oscillations. The oscillations can also be calculated using a computer model. To use a computer model the required data is entered in the program and the desired results are calculated. Current technology enables making precise computer calculations, which enables us to use them. Computer models are much faster and cheaper to implement compared to the physical models. This graduation paper will explore the analyses of a hydraulic shock and oscillations of water masses in cylindrical and generic surge chambers and their comparison. For the purposes of the water hammer analyses 10 experiments were made with different input data. By analysing these experiments the conclusion was made that the water hammer velocity isn't dependent on the water level in the accumulation nor in the surge chamber, but it depends on the flow. For the purposes of the water mass oscillation analyses 5 experiments were made for the cylindrical and 5 for the generic surge chamber. The chamber were tested separately so they can be compared. To conclude, generic surge chambers are currently being used in an increasing frequency because they are superior to the cylindrical ones in every way. Their branched construction enables them to mitigate the same oscillations in a shorter time period and in a smaller volume space.