If you can find a friendly member of station staff at the location you want to watch at they might have access to Trust, but they won't be allowed to give you consist details for future trains as it can be sensitive info in the current security climate, depends on the policy their company has.
I tried putting in folkestone and dover and didn't come up with any freight movements, so where abouts are you going to watch trains?
I'm afraid we are only allowed to give general details such as a good time to go there, other local enthusiasts might have a direct source of Gen so try chatting to other photographers you see and see if they have a contact for that day.
