Recliner wrote:
Incidentally, I notice that, slightly downstream, there's an old, derelict
pier just opposite the old North Woolwich station -- was this used by the
ferries in the past? Or was it to serve passengers who arrived at the
station?

It's marked as 'LNER pier' on this map:
http://www.disused-stations.org.uk/n/north_woolwich/
adjacent to the 'Free Ferry' which goes from what looks to be the current
pier. According to the text, the Great Eastern ran a North to South
Woolwich ferry competing with the free ferry which closed in 1908, but the
pier was then used for river steamers. Looks like the pier has been there
since 1847.

Theo