Abstract: An auxiliary dump box accessory is provided for combining with a conventional flatbed bale (of hay) loader, for effectively converting the flatbed bale loader and the underlying conventional truck into a dump truck. Thus the dump box accessory gives the flatbed bale loader alternative utility(ies) besides the standard utility of loading and transporting large cylindrical bales of hay, including among others all the utilities typically provided by dump trucks. The dump box rests on the flatbed for use in a conventional upright position. However, when the dump box is unloaded for storage during non-use, it is deposited onto a base support surface such as the ground in a position in which it is substantially inverted.