The airplane struck a crane that was next to the taxiway, in a taxiway safety area. The first officer watched the right wing pass over a flatbed truck, several feet outboard the ‘number four’ engine nacelle. He thought the wing would also clear the crane, which was outboard and past the truck. The airplane continued taxiing, and the right wing struck the crane, causing damage to that wing, and causing the crane to topple over, and eject the occupant. The only conversation between the crewmembers during the 46 seconds prior to the accident, was a ‘right side clear’ callout by the first officer. The crane had been located in the taxiway safety area by subcontractor personnel, who took it upon themselves to remove safety barriers. There were no supervisory safety personnel at the accident site. Probable Cause: The first officer misjudged the clearance between the right wing and the crane. Factors included the subcontractor’s unauthorized placement of the crane in the taxiway safety area and insufficient oversight of the subcontractor’s operations.