This paper explores the design strategies for hybrid pole- or trunk-climbing robots, focusing on methods to inform design decisions and assess metrics such as adaptability and performance. A wheeled-grasping hybrid robot with modular, tendon-driven grasping arms and a wheeled drive system mounted on a turret was developed to climb columns of varying diameters. Here, the key innovation is the underactuated arms that can be adjusted to different column sizes by adding or removing modular linkages, though the robot also features capabilities like self-locking (the ability of the robot to stay on the column by friction without power), autonomous grasping, and rotation around the column axis. Mathematical models describe conditions for self-locking and vertical climbing. Experimental results demonstrate the robot's efficacy in climbing and self-locking, validating the proposed models and highlighting the potential for fully automated solutions in industrial applications. This work provides a comprehensive framework for evaluating and designing hybrid climbing robots, contributing to advancements in autonomous robotics for environments where climbing tall structures is critical.

8 pages, 9 figures; This work has been submitted to the IEEE for possible publication