This document provides an overview of a first, feasible design for the X-ROTOR wind turbine, with particular focus on the jacket support structure. Based on the existing aerodynamic model, load simulations were performed to assess the structural performance and safety of the jacket. The initial jacket design has been adapted from the OC4/Upwind jacket and choices made for the pre-project feasibility study. Some simplifications have been made, to make the design comparable to existing structures from these projects, and a first attempt at sizing optimization has been performed. The resulting preliminary design is documented in this report. The main conclusion from this work is that with the current large load cycles from the 2 bladed rotor the jacket will need to be somewhat stronger than for a corresponding horizontal axis wind turbine. Also a number of items have been highlighted that will merit more detailed study in the future, especially when more accurate aerodynamic loads become available.