Abstract: The specification describes a double dolly for use with a conveyor for moving an object by engagement with the object. The double dolly comprises a first roller, which rotates about a first axle, a second support roller which rotates about a second axle, a rotatable safety bar located in advance of and below the lower reach of the first roller, and a frame for securing the rollers, axles and safety bar to a conveyor. The first roller, which engages the object is freely rotatable prior to contact with the object. The support roller is in contact with the surface over which the object is being moved for transferring load exerted on the dolly by the object to that surface while permitting movement of the dolly. The safety bar blocks the gap between the supporting surface and the first roller. The rotatability of the safety bar prevents its binding on the supporting surface in the event of tipping of the dolly.