This image was acquired from
flickr. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
outdoor vehicle railroad PSA USN Its Shocktube Not Weapon fivepound explosive charge detonated at the apex of this foot conical shocktube can simulate the blastwaves generated by simultaneously firing six of the most destructive blockbusters ever dropped during World War II. William S. Filler Naval Ordnance Laboratory physicist