Fire brigades and special rescue agencies are often demanded to operate for search and aid of human lives in extremely dangerous scenarios. The use of robotic tools can make those operations safer for the operators and more efficient in terms of time and allocation of resources. This contribution describes the development of the newest tracked vehicle HELIOS IX. This mobile platform equipped with a manipulator represents the first stage of a Japanese national founded project. It aims to the development of a robotic system to be utilized in extreme environments such as rescue operations in heavily stricken urban areas. With respect to the previous prototypes the mechanical design and the system architecture is described. A new gripper is also introduced and tested together with few mobility experiments of the platform.