Charlie The Choo Choo!
Although Blaine seems to be a sentient train, he is really much more, a "ghost in the machine", the artificial intelligence that resides in Lud's mammoth underground computer systems. Over time, as the world has moved on and the computer system slowly breaks down, Blaine becomes more and more deranged.
The crashed blue mono seen from the Send bridge is revealed to have been named Patricia, apparently possessed of a separate sub-personality within the Lud computer. The Patricia personality lapsed into a depression, and could not stop crying. Blaine "liberated" her by removing certain blocks in her programming, and once freed, she committed suicide, derailing herself in the river. It is a sign of Blaine's cruel personality that he finds this amusing.
Ripped shamelessly from Wikipedia.
"... and I will be a happy choo-choo train until the day I die."
the picture I want of Charlie The Choo Choo won't load....uuurgghghghg