Rugby yard had a grounded 16 tonner with the drop doors removed, it had "brake van coal, P-way keep out" painted on the side, I have modelled it in 00 gauge using an old Airfix kit, I think it was topped up by rail in the 1970,s, derelict in the 1980,s
Northampton used bags of coal, stored in a Internal User 12 ton van, presume the coal was delivered by Road using a local merchant or BR staff
Bletchley had a store of coal in plastic sacks stored behind the Staff Amentity Block next to the carriage sidings, not sure how it was delivered, I don't remember any coming in by rail in stores van, presume it was delivered by Road either direct from a merchant or by BR staff
Richard