What is a scaling tower with a battering ram attached?
The term "siege tower" was used for some scaling towers. But few had both ladder towers AND a ground level battering ram to break down doors and walls.
A scaling tower was used in ancient wars to allow soldiers to reach the top of an enemies' town or fortress walls. If a battering ram is attached to it, then scaling the walls over an entrance to a fortress or city plus using the battering ram to break open the forts doors can be accomplished. This type of war "machines" were used into the Middle Ages.
Obviously Its A Scaling Tower With A Battering Arm Attached!!! _ _ _ Phil: Ummm, "obviously" the last guy didn't know (See what I did there?)! What I think you are looking for is a siege tower. It was used specifically in the First Crusade and was essentially a tower with wheels that could reach the extent of Antioch's walls.
As a device intended to knock down a sealed door of some kind, a battering ram is indeed a simple machine; or, at least, it can be. For, while sophisticated battering rams have been created and utilized, the trunk of a tree can serve just as well, when and where the gate or gateway to be rammed open is appropriately sized.