Can any English teachers help with a quick question?

[Englishhelpneeded]

DS has GCSE English homework. Needs to say what language technique is being used in the following two sentences. I have English A Level but the only thing I can think of is a triple but I can’t remember if that’s the right term. So…

1. It’s like standing on a bridge. A bridge that’s on fire. A bridge that’s on fire and it’s burning from both ends.
2. You’re sailing a ship alone. A ship that’s enormous, and on fire, and no one has taught you how to sail.

DS says he vaguely remembers doing this but has never heard of a triple and cannot remember. Google is no help do MN it is!

Does he mean foreshadowing?

There is no "exact word" the exam boards are looking for

But never mind - you're a doctor now!

All the faffing about with terminology is smoke and mirrors (metaphor) - as MrsHamlet says, the marks are for effect. Fancy subject terms actually end up detracting from the answer.

Ok, he’s looked back and found his notes which call it a ‘climactic power of 3 metaphor’. I’ve passed on all the recommendations that the effect is more important than the term. Thank you everyone for your input.