Welcome to OpenStreetMap and many thanks for updating this and other features around Gravesend.

Feel free to ignore the following, as the access tagging "should" work for all but the most broken routing software anyway.

If the closure is likely to be for at least several months or indefinite, it might be worth adding changing it to disused using a lifecycle prefix e.g. disused:highway=service

It might also be worth adding the gates, as nodes with barrier=gate + access=no + locked=yes

The documentation on lifecycle prefixes is at https://wiki.openstreetmap.org/wiki/Lifecycle_prefix