Abstract: An assembly for supporting a flexible service line between a base structure and an object body mounted to the base structure for movement about lateral and elevation gimbal axes includes lateral and elevation drums fixedly mounted to the body and base structure, respectively, and an arm interconnecting the drums. A spiral groove is defined in the periphery of each drum for receiving looped portions of the flexible line therein. The arm supports a portion of the line extending between its looped portions. Also, the arm is rotatably mounted at its opposite ends to the drums for accommodating relative movement between the body and base structure about the respective gimbal axes. The looped portions of the flexible lines are confined in the grooves on the drums and may expand and contract therein as the body moves relative to the base structure about the gimbal axes.