I suggest you check Real Time Trains (RTT) at Crewe to help choose the date for your visit.
For example, this is the freight list for Thursday 23 July 2015:
http://www.realtimetrains.co.uk/sear...der=wtt&toc=ZZ
Note that RTT data remains on site for only 7 days, so you will have to choose a new date if you use this link after 30/7/2015. Also note that some trains marked "ZZ" may be MPVs or mobile track machines rather than full-length freights. Also note that "Q" trains run only when required, and that can be quite infrequently.
Hartford, Winsford or Acton Bridge would be better nearby locations for freight photography.