Trust is essential when using technology. If people do not trust new technology, they do not accept it. If people do not accept new technologies such as autonomous ships, their development is hampered in the absence of financial support. The importance of trust brings into question the essential conceptual components of phenomena that contribute to trust. This knowledge is required for the basis of investigating trust in technology. Especially, it is important to understand why humans trust. The reasons can be intuitive but they can also be supported by rational arguments. The latter type of trust can be called rational trust. A beneficial way of considering rational trust in technology can be reached by defining aspects of technologies that should be investigated when attempting to design for trust in technology. Therefore, the basic conceptual dimensions of technology supported actions are analyzed in order to define the essential elements of rational trust in technology.