The Southern Railway constructed a number of bogie brake vans to provide smooth riding vans for guards on express goods and parcels trains. Initial examples being rebuilt from redundant electric unit parcels cars these vans ride like a coach, in additon to having good weight and an efficient brake.
Many of these vans survived in BR ownership, latterly with the engineering departments who appreciated the combination of a mess/riding van and tool storage in the verandahs either end. This example allocated to the S&T (signal & telegraph) engineers department has been painted in the departments' own 'SatLink' livery.