A Puzzle Classic

I have recently come across a discussion of the famous Smith, Jones and Robinson puzzle, while looking for something to read in the library. When I solved this little puzzle, I remembered what I was told as a child: in mathematics, every word matters... I thought I would share this problem here, perhaps others may get tempted too, and do something completely different when they were supposed to work... :)

On a train, Smith, Robinson and Jones are the fireman, brakeman, and engineer, but NOT respectively. Also aboard the train are three businessmen who have the same names: a Mr. Smith, a Mr. Robinson, and a Mr. Jones. Here is what we know:

1. Mr. Robinson lives in Detroit.
2. The brakeman lives exactly half way between Chicago and Detroit.
3. Mr. Jones earns exactly $20,000 per year.
4. The brakeman's nearest neighbor, one of the passengers, earns exactly three times as much as the brakeman.
5. Smith beats the fireman at billiards.
6. The passenger whose name is the same as the brakeman's lives in Chicago.

Who is the engineer?