This paper describes the aim of designing, building and testing magnetic wheel based an autonomous climbing robot, for use in conjunction with Non-Destructive Testing (NDT) inspection on vertical towers. Through extensive review of previous generations of climbing robot, a hybrid wheel and permanent magnetic adhesion system has been designed and discussed in this paper. Using mathematical modelling and Finite Element Analysis (FEA) of differing magnet geometries, an adhesion system has been developed to produce the required amount of adhesion force and has been empirically tested at several intervals are presented in this paper. To complement this adhesion system, a lightweight, cost effective body is designed using 3D CAD software and manufactured using rapid prototyping methods. This has been done to incorporate the electronic equipment used to sense the working environment, drive the robot and carry equipment capable of performing defect detection tasks. To do this, a range of sensors, motors and auxiliary equipment has been used and controlled by a microcontroller. Finally, a functional scale prototype are manufactured, assembled and tested on a cylindrical test rig that closely imitated its intended work environment.