1) Stop using caps.
2) Your answer. It begins in the room right before the red room , with the shield generator in it.
Go to the end and use the shield regenerator if you need to, and then
go outside the doors on either side of you, out on to the grate
Stand on the walkway facing towards the river, and notice that a part of
the fence is broken. Look downward here, and notice what happens each
time a tram flies into the flashing red room. A pipe will extend below
you, venting air, and will then retract. Jump down on top of this pipe,
crouch as close to the wall as you can, and then climb inside once it
retracts. Through this tube you will emerge in a small area below the
tram room. Destroy the four red pillars, as well as the lift in front of
you. The room above will no longer be dangerous. Move on to the lift,
and it will take you up. Once in the room, climb on either of the black
rail archways, and drop down on top of the tram. Ride it through the
passageway, around the corner and then jump off to the left, where
you'll see small area leading to a dark green passage. Crawl in, and get
ready to deal with some really annoying bugs with big teeth. I suggest
using your stun baton on them so you don't waste all your ammo. Proceed
through the passage; it doesn't matter which way you go, both directions
lead to the same place. At the end, you'll see a couple dead miners and
a piece of mining equipment. Hit the switch on the back, and it will
drill through the wall for you. Be careful, it leads to a small duct
area with two holes overlooking a pit of lava. The drilling machine
falls through the first hole...move to the second, break the grate, and
wait for the next mining tram to come by. Its path leads right
underneath the hole, so jump down on top when you see it. While you're
waiting, you can kill most of the enemies in the room below. Once
you're on the tram, jump off when it gets close enough to the walkway.
stuck in an eternity of sunshine and chocolate.