A Track Circuit Failure (TCF) in the middle of the station throat has tied up the Main and Electric Lines into platforms 10-18 all morning. The TCF has now been fixed, a signal failure at Signal 54 on the Up Suburban Line and a points detection failure on the Down Suburban Line between Bethnal Green and Cambridge Heath are causing more headaches. How quickly can you get the trains into Liverpool Street and, subsequently, the backlog cleared?