And once you reach the box there are the 4 flights of stairs to ascend. On my visit to Severn Bridge Jn last year NR refused to allow one of our party to go to the box due to his poor sight. Not helpful if you're trying to attract visitors.
Par
I don't think NR are remotely interested in attracting visitors to their signalboxes, you're just lucky if you happen to come across someone within the organisation who is kind enough to indulge your interest by permitting and arranging a visit and they're particularly risk averse with track side access. In the unlikely event of an incident occurring it would just be the final nail in the coffin for visits as no doubt there are plenty of individuals within NR who would like to place a blanket ban on them.