Drilling through castle walls with a Terebra

I stumbled across a new type of siege engine that I hadn’t previously known about. Well, when I say it is a “new” type of siege engine I mean new to me. It has been around for centuries. I just never heard of it before. It is called a Terebra.






I was doing some castle research, reading a book called British Castles – by Charles Ashdown when I ran across the Terebra.

This is all Ashdown said about it:

The Terebra.— A machine based upon the classical terebra was also in use. It consisted of a heavy beam which could be rotated; the iron head being furnished with a spike of square section was inserted in a joint into which it bored its way, breaking up the surrounding stones and facilitating their removal.

So I did some more digging to try to get a better sense of what it was and how it looks. I did find a few pictures. A couple of which I have put here in this blogpost.






This second picture is in German and the literal translation of its name is “Wall driller” which is apt.

It is an interesting siege engine because most engines rely on brute force to simply destroy castle walls whereas the terebra is a bit more elegant in that it drills!

I don’t think they were used very often, if at all. It seems to me you have to get awfully close to a curtain wall or a castle wall to use it. And this leaves you vulnerable to archers for an extended period of time.

But my understanding here is that the point isn’t to drill through the stone of the castle but to drill through the mortar between the stones which seems more feasible. A series of holes drilled in the mortar would weaken the wall making it more vulnerable to brute attacks by other siege engines.

Anyhoo, It is an interesting word and an interesting, relatively unknown, type of siege engine.

About the Book
The book I was reading is called British Castles – By Charles Ashdown  and it is in the public domain. I have it as a free download in ebook and kindle format on my website here:
Free ebooks about Castles