James Rutherford, of South Shields, pleaded guilty to affray and was sentenced to 12 months on Friday 23 September, at Newcastle Crown Court. He received an additional three month custodial sentence for other non BTP offences.
The court heard how on Sunday May 2, officers responded to a report of an assault on board a Metro train between Pelaw and Fellgate Metro stations.
A passenger on the service had asked a group of three young men, which included Rutherford, who had sat down next to him, if they would wear masks.
An argument and physical altercation ensued and Rutherford responded by slapping him in the face.
The three then left the train by forcing the carriage doors.
The victim sustained extensive facial fractures and finger fracture in the incident.
Rutherford was identified and arrested following a media appeal.
Investigating officer DC Shaun Kelly, said: “This sentence should serve as a stark warning to others that violence will never be tolerated on the railway.
“If you’re a victim of, or witness to, violence on the railway, I urge you to report it to us by texting 61016 or calling 0800 40 50 40. In an emergency, always dial 999.”