A simple tune played in the Key of B (but using the chords for the key of G).

Capo 4


[Verse 1]

             
Once upon a ti

              
me there was a

        
n engineer, 
             
who drove a lo

              
comotive both 

      
far and near, 
             
Accompanied by

              
 a monkey who 

      
would sit on a

 stool,
             
watching every

           
thing the engi

           
neer would pul

l.

             
One day the en

              
gineer wanted 

         
a bite to eat,
             
He left the mo

              
nkey sitting i

            
n the driver's

  
 seat,
             
The monkey pul

              
led the thrott

            
le the locomot

ive jumped the

 gun,
             
and at 90 mile

            
s an hour down

            
 the main line

 
 run.


[Chorus]

             
The big locomo

             
tive is right 

   
on time,
             
the big locomo

            
tive coming do

       
wn the line,
             
The big locomo

            
tive number 99

,
           
left the engin

            
eer with a wor

     
ried mind.


[Verse 2]

             
The engineer g

              
ot the dispatc

          
her on the pho

ne,
             
he told him al

              
l about his lo

           
comotive was g


one,
             
he said get on

              
 the wire swit

       
ch operator to

 right,
             
cause' the mon

             
keys got the m

           
ain line sewn 

   
up tight.

             
The switch ope

              
rator got the 

          
message in tim

e,
             
Said there's a

              
 north bound l

             
iving on the s

        
ame main line,
             
Open up the sw

              
itch we gonna 


let him on thr

ough,
             
cause the monk

             
ey's got the l

           
ocomotive unde

  
r control.


[Chorus]

             
The big locomo

             
tive is right 

   
on time,
             
the big locomo

            
tive coming do

       
wn the line,
             
The big locomo

            
tive number 99

,
           
left the engin

            
eer with a wor

     
ried mind.


It is the same progression throughout the song.
Improvise and have fun with solos, repeats, etc.
A great and simple fun campfire song.