"Michael R N Dolbear" wrote in news:01ccaafd$03acb600
$LocalHost@default:

Theoretically an announcement and/or display could have been made on
the SWT train, on Vauxhall NR or on Vauxhall LT but since the last
didn't happen or was ineffective in changing behavior (since you got as
far as Pimlico) the chances of getting an effective message to those
outside TfL seems small.

In my experience, if there is disruption on the Victoria Line it is very
common for there to be an announcement on the platform at Vauxhall as
trains arrive, and there are also sometimes announcements on the trains.

It takes a good 5 minutes to get from a SWT train to the Underground at
Vauxhall, and probably several minutes for the control room to assess an
incident, to decide whether it merits an announcement and to pass the
information to whoever makes the announcement, so I think it is inevitable
that the flow of passengers can't be stopped instantly.

Peter CS