Czechoslovak heat pipes are currently spreading in their scope of aplication. In co-operation with Czechoslovak manufactures of heal: pipes, several systems using these components and a number of separate heat pipes have been developed for the SKODA enterpris. In the design of these components, the specific in-service conditions related to their application in traction vehicles have been taken into account. The. paper deals with three separate fields of application. The first of these is concerned with the first resulted of testing of a heat pipes exchanger mounted -experimentally at a locomotive 69E0 (manufacturer internal designation) locomotive to cool the control electronic box during the summer. The second application treated in the is that of maintaining the operational temperature of integrated circuit within the required range during operation by means of a heat pipes dundle. Finally, results of efforts aimed at broadening the field of power semiconductor elements coolers available are presented in the third section of the paper.