time machine disk duplication

greetings, I'm trying to create a backup of my time machine disk. You know, in case my external drive dies or malfunctions (it happens). I use Carbon Copy Cloner (CCC) to do this with other disk, like my Lightroom Photos. I have a primary and a backup, both external. Put one on each side of my MBP and carbon copy cloner creates an exact duplicate. I always have two identical copies in case my primary dies. Seems CCC won't clone the TM disk saying that Apple has something propriery and won't allow third parties to back up their TM data. So, how do you do it? Does anyone else do it by some other means? Thanks