OpenStreetMappers: any ideas as too how to map this pipe?

I believe it is there to vent gases as the location is on a former brownfield site (Raleigh bike factory), and some of the substrate may be rubble from the demolished factory.

#OpenStreetMap #TaggingConundrums

Prizes for suggesting a sensible value for barrier=* on this #BOAT? (Penzance Byway )

I could just about squeeze past the wheel-less van.

#OpenStreetMap #TaggingConundrums #PublicRightsOfWay #Byway