The drawings not to scale.
I was thinking maximum train length would be 4-6-0 and 6 bogies, though most would be shorter
The top "bay" is indeed for loading with both a end loafing and some cattle pens, possibly use for summer excursions from London would be another possible use
TonyMay - I was thinking more of a line heading north towards Lowestoft, though, Great Eastern and Jutland Joint..........