I would say, Simile because this compares the feeling of seeing the machine to being stabbed by a dozen awls. Similes use like or as to compare two different objects, so that is what leads me to believe this. It cannot be a symbol, because that does not represent anything. It cannot be personification because it does not take a nonliving object and give it human features. I would say that's it a metaphor, but it uses as, so I firmly believe that it is a simile..