The rod itself would penetrate hundreds of feet into the Earth, destroying any potential hardened bunkers or secret underground sites. More than that, when the rod hits, the explosion would be on par with the magnitude of a ground-penetrating nuclear weapon – but with no fallout.

It would take 15 minutes to destroy a target with such a weapon.

https://www.wearethemighty.com/articles/these-air-force-rods-from-god-could-hit-with-the-force-of-a-nuclear-weapon/