If you have passed assessments already I'd suggest firing off an email assuming you haven't been unsuccessful at sift but perhaps haven't heard backAs has been noted be patient and don't call recruitment, they are still sifting applications there are over 21,000 to get through, I work for GTR and know that they simply dont want to be badgered by applicants, they will come to you when it is time
I secured an interview in summer 2015 this way and the rest is history