The aim of this report is to obtain relevant data for the dimensioning procedure of the shell structure of an ice-going vessel in the Baltic. The dimensioning ice loads have formerly been obtained by indirect methods because there is a lack of reliable analytical models of ice pressure and load and because so far empirical data of them is not available. The only values published about ice loads are calculated indirectly from the response of the shell structure. The response is measured with strain gauges. This method does not give the value of ice pressure or load area, only an estimate of the total load. Thus was decided to design a measuring system for local ice pressure. Nowadays practically all the estimates of dimensioning loads for various structures are of stochastic nature. Also the ice load is a stochastic variable and to investigate its characteristics a special recording system was developed. This system was in operation onboard the Finnish icebreaker Sisu during winter 1978. In this winter the output of four gauges was analysed. These gauges included two V-shaped strain gauges on the plating and two new ice pressure gauges. The measuring period was from 24.2. to 7.5. 1978. During this time the icebreaker was operating in the Bothnian Bay mainly from Kemi.