Its not good when there's no one to turn to for help its like being in the school yard again , a big part of the problem is realising its going on and asking for help , keeping a dairy is a good thing to do use this to approach who ever is in charge when the times right , it's very difficult to stop bullying yourself ,so easy to say stand up to the bully but not easy to do ,try to make friends with the last new boy before you in chances are he was the target before you arrived strength in numbers ,
One thing you could try is next time your all sat having a tea break ask him calmly and firmly why he's bullying you in front of his peers and make it clear you don't like it , I'll put a bet he's doing it or has done to everyone
Good luck keep your chin up and don't let the barstewards win
Rob