There is a lack of high-payload, low-cost mobile robot bases with high enough levels of mobility to perform effective human-robot manipulation. This research aims to provide an open-source option for a mobile base that can aid humans in carrying large and heavy objects. We designed, constructed, and developed code for an omnidirectional mobile base to enable research in human-robot co-manipulation applied to search and rescue situations. The base was designed with four individually steerable caster wheels to facilitate omnidirectional movement, allowing it to move in any direction to dynamically match the motion of a human. These casters are mounted on differential rocker arms to allow the base to move over small to mid-sized obstacles and objects on the ground. This should allow the base to be better suited for traversing rough terrain often found in search and rescue operations. The base is equipped with a pneumatically actuated soft continuum robot arm attached to a rotating turret to interact with the object being carried. This research aims to extend or build on the results of Freeman [BYU Scholars Archive, 9433 (2022)] and Jensen [Frontiers in Neurorobotics, 15, 626074 (2021)] by providing a testing platform for human-robot co-manipulation experiments using the human-human data co-manipulation data gathered. The mobile base can achieve speeds of greater than 3 m/s (6.7 mph) in any direction and can carry a payload of greater than 68kg (150lbs) making it suitable for human-robot co-manipulation of large objects and heavy loads. It was additionally able to run on battery power for over an hour and can traverse uneven ground. The future trials run with this mobile base will provide greater insight into the parameters involved in effective co-manipulation of heavy objects and will be used to for insight into robot assisted search and rescue tasks.