I do not recognise this loco as the "little engine that could"! In the book that I loved as a child, the loco was a 2-4-0 with tender, red bodied and lined in gold with a straight stack painted black.
The hero was the smallest loco in the terminus and had his own local mixed passenger and freight run. One day an urgent freight run was required when all the "BIG" engines were out or being seviced/repaired. the little engine was "IT".
The rest of the story is a telling of a locomotive's journey.
"I___can move___this" says the loco trying to start the load. "I_can_move_this" etc until it reaches the grade. Then as the effort builds, the tempo slows to "I think I can, I_think_I_can, I__think__I__can, I___think___I___can, I____think____I____can" Etc, slowing until the loco and load reach the crest of the grade, then it is "I___knew___I___could, I__knew__I__could" at ever increasing speed.
The words and their pacing, mirror the drive stroke and exhuast stroke of the two cylinders accelerating the stationary train and the climb and descent.
Just had a look at one of the wikipedia entries on the "Little train that could". Claims that the drawing is based on the C P Huntington, funnel is right, is 4-2-4 (sorta) and is a steam engine.
BUT the phsyco babble!
It is an onomatopeaic tale to amuse small children! The sound of the engine in various activities - that's the story!
I guess that children today never hear steam locos working. I lay in my bed before school time, hearing the morning "up" passenger train working up the Agnes bank to Toora, "I___know___I___can, I____know____I____can" every morning from the age of 2 until I was 9.
Off my soap box now.