How do I get to the ladder.

Hint 1 of 8:

You need to block the sewage flowing through the channel.

Hint 2 of 8:

The machinery in the room to the right drops the gate.

Hint 3 of 8:

A gear is supposed to go on a bare shaft for the machine to work.

Hint 4 of 8:

In room with ladder, GET GEAR sitting in the corner.  +1

Hint 5 of 8:

Go back to other room and USE GEAR ON SHAFT.     +5

Hint 6 of 8:

MOVE SWITCH on box on left side of machine.

Hint 7 of 8:

Go through left doorway. can now cross to ladder.

Hint 8 of 8:

GOTO CHANNEL then walk across the channel then GOTO WALKWAY.