Cameron Wilson and three others pretended to be asleep when the woman asked to see their tickets on the train which left Sutton Parkway, just before 2pm, on March 30.
“They refused to buy tickets, and she told then she wouldn’t release the doors unless she did,” said prosecutor Robert Carr.
Wilson said: “Do you think I give a f*** about buying anything?” and began swearing in front of the other passengers, included children and elderly people.
He gave her a debit card to pay for the four £2.60 tickets, and then told her it wasn’t his card.
“One of his companions threatened to punch the conductor,” said Mr Carr. “She locked herself in the rear cabin of the train.
“The defendant tried to get into the cabin. She watched them get out of the train using the emergency door lever.”
The court heard the incident left the woman “physically shaking and upset,” and “feeling frightened and scared to go out.”
In a victim impact statement she said she thought she saw one of the gang when she was out shopping and this caused a panic attack.
Police traced Wilson because he left his card behind.
Wilson, 18, of Brookside Avenue, Mansfield Woodhouse, admitted using threatening and abusive words when he appeared at Mansfield Magistrates Court, on Thursday.
The court heard he appeared at Nottingham Magistrates Court, on August 24, for receiving stolen goods, where he was given a community order.
Rebecca Williams, mitigating, said: “In his own words his behaviour was stupid. He tried to make a payment. It was only due to the aggressive behaviour of the others that this didn’t happen.”
District judge Andrew Meachin said: “This lady was terrified. She had to take refuge in her own train.”
He fined Wilson £120, and ordered him to pay £85 costs and £50 compensation.