SuperCage - Home SuperCage Cages are high quality american made construction cages that can be fitted to the end of the boom on most cranes. These cages are used for construction, non-personnel, medical evacuation and SuperCage Cages are high quality american made construction cages that can be fitted to the end of the boom on most cranes. These cages are used for construction, non-personnel, medical evacuation and welding purposes.