George Kamau, 28, was on a stationary train at Enfield station on March 2 last year when the victim attempted to board the service.
Kamau left the train and began beating the stranger, kicking him several times to the head causing him to collapse to the ground unconscious.
Other passengers rushed to help the victim but Kamau continued the attack by grabbing a woman’s crutch and using it to beat him.
The victim was left covered in blood with his legs under the train as Kamau walked away, before he returned to the train and took a seat.
The victim was hospitalised with life threatening injuries and suffered three strokes following the attack.
He now has permanent hearing loss and significant scarring to his face.
Kamau, of Bluebell Avenue in Manor Park, was arrested at the scene.
He later pleaded guilty to grievous bodily harm and on Monday, April 28, was sentenced to an indefinite hospital order.
Detective Constable Sophie Markham said: “This was a horrific and completely unprovoked attack on an innocent stranger.
“The victim has suffered a really traumatic ordeal and I hope that today’s outcome may in some small way assist with his continued recovery.
“The railway network and the wider community is a safer place now that Kamau is off the streets.”
