A carriage assembly for controlling a steering wire steering mechanism within a flexible shaft, for use in gastroin-testinal tract surgery, comprises a plurality of selectable engageable motors including two drive motors (100) for selectably rotating drive shafts (120) of a surgical attachment, two steering motors (130) mechically communicating with corresponding pulleys (160) around which are coiled directional steering wires (140) communicating with a flexible shaft to enable the selective direction of the flexible shaft within a spatial plane, wherein within the assembly housing the steering motors travel on a steering motor carriage (200) and the pulleys travel on a pulley carriage (190) which is biased by a spring means (220) away from the interior wall of the housing, which biases the steering wires toward a taut state. The bias can be overcome by a carriage motor (240) mechanically communicating with the pulley carriage to cause the flexible shaft to go limp. Also disclosed are a series of surgical attachments which may be coupled to and utilized in conjunction with the carriage assembly.
