Just three weeks after getting out of Gaol in April 1871, 16-year-old Ned was arrested again. He had ridden a friend's horse into Greta. He did not know that his friend, Isaiah "Wild Wright", had stolen the horse from the Mansfield post office. There was a fight when a policeman, Constable Hall, tried to arrest him. Hall tried to shoot Kelly three times, but his gun would not work so he hit him over the head with it instead. Kelly was sent to Pentridge Gaol in Melbourne. After four months he was moved to the prison ship, "Sacramento", at Williamstown. Prison ships were old ships that were used as extra prison space. Prisoners from the "Sacremento" worked during the day building a sea wall at Williamstown beach. They also worked on building a fort for the guns that were protecting Port Phillip Bay. Kelly was released from prison on 2 February 1874.