Unable to answer "What type of bollard is this?" – Bollard – https://osm.org/node/996770390 via StreetComplete 58.2:

There is a barrier point, but it's overgrown. It is unlikely that it is still in use.

Attached photo(s):
https://westnordost.de/p/230844.jpg
https://westnordost.de/p/230845.jpg