Question

He is a machine, working nonstop for over nine hours!

Answer 1

That is an exclamatory sentence. (i think) The independent clause is "he is a machine".

I'm sorry if this isn't the right answer you were looking for; I tried my best to understand what you were trying to ask.

Answer 2

This statement is a metaphor. Metaphors are figures of speech that refer to one thing by alluding to another. It can be used to clarify, simplify, or define something. In this sentence, it is said that this man (I'm assuming) is such a hard and persistent worker, that he is "like a machine".

I hope this helps in one way or another. :)