Abstract: An arch structure serves to pivotally connect a grapple to a main frame of a tractor, an articulated wheel vehicle, or the like. An imaginary longitudinal axis extends substantially centrally with respect to the vehicle in forwardly and rearwardly extending directions. A winch has a casing that is mounted on the rear of the vehicle's main frame, and has a winch shaft that extends normal to the longitudinal axis of the vehicle. The arch structure is pivotally connected to the vehicle's main frame by means that includes a pair of side arms for detachable connection to the main frame of the vehicle, with means on the side arms for pivotally supporting the arch structure including a pivot pin connected to each of the side arms and in alignment with each end of the winch shaft. The arch structure includes spaced leg members, the lower ends of which are mounted on pivot pins arranged such that the pivot point of the arch structure is coaxial with but not connected to the axis of the winch shaft.