Tomb Raider Underworld Q&A

the mission says to find the thor's hammer inside a mechanic room smth of that i think.i'm stuck,what i must do?
the room i am has some big hammers on the wall whitch they are moving THE END :P. plz my uncle is burning for this answer.

on the south mexican level,th bit where you jump over the three pits in the cave with the giant spiders the 1st bridge is not up and in every walkthrough i have read it should be up can u tell me why it is not