Cowpie had the following, with two chord versions:

FIREBALL MAIL
Recorded by Roy Acuff
Written by Floyd Jenkins (aka Fred Rose)

CHORUS
[G] Here she comes - [Em] look at her [G] roll
There she goes - [Em] eatin' that [D] coal
Watch her [C] fly - huggin the [G] rail
Let her [Em] by, [G] by, [D] by, the Fireball [G] Mail.

Let her go - look at her steam
Hear her blow - whistle and scream
Like a hound - waggin' his tail
Dallas bound, bound, bound the Fireball Mail.

Engineer - makin' up time
Tracks are clear - look at her climb
See that freight - clearin' the rail
Bet she's late, late, late, the Fireball Mail.

Watch her swerve - look at her sway
Get that curve - out of the way
Watch her fly - look at her sail
Let her by, by, by, the Fireball Mail.

CHORUS

(or standard chords)

[G] Here she comes, look at her roll
There she goes, eatin' that [A7] coal
Watch her [G] fly, look at her sail
let 'er by, by, by, it's the [A7] Fireball [G] Mail.