Sentence:  All trains from start of service up to the 13.57 <WSD>ex</WSD> Norwich (16.45 <WSD>ex</WSD> Nottingham) are 4 cars between Nottingham and Liverpool and all East bound trains are 4 cars from Liverpool Lime Street as far as Nottingham. 
Meaning of the word marked with <WSD> tags:  (of a train) the place the train originated from or called at prior to the present location.