Hey Logi, that's almost cheating ;-) I mean, a language with a command to list the program itself...duh!
Eman, correct of course, here's another solution:
This sentence has thirtyone letters.
As regards the Titanic thing, I can't remember anything about that film except that I was forced to watch it after a long, hard day of work and fell asleep almost immediately. But from the description I'd guess the idea was to prevent the wheel effect of the propellers (well-known to anyone who's ever tried to maneuver a boat in a small harbour), which would happen if you had 2 props turning in one direction and one in the other.
f.
(edited because I can't read)