The main goal of this project is to develop a device that moves along the wires and traverses the standard mast tip of the Swiss power industry. Figure 1 shows such a mast tip that is widely used in Switzerland and most other European countries. On each side one can see the ground cable leaving the tip towards the next mast. These cables do not transmit power and are installed on top of the other cables to protect from damages caused by lightning. The main difficulty to deal with was to find a mechanism that can move on the sloping wire (also around horizontal angles) and ride over all the different obstacles on top. So far, different research groups have developed several robots that can cross obstacles on the wires [1-3]. Most of these robots use active structures that result in designs with a relatively high number of actuators and sensors – leading to a complex control and resulting in relatively big and expensive devices of slow speed. In order to realize a robot that is simpler, faster and more robust, the main goal within this work is to realize a vehicle structure with a passive articulation that can just roll over the specified obstacles.