Peter Masson wrote to uk.transport.london on Sun, 19 Dec 2004:

The Night Ferry used platform 2, because it was long enough and because it
had access to the customs and immigration offices. Platform 2 was also used
for Royal Trains - State Visits often came in to Gatwick, and the visting
Heads of States were conveyed to Victoria by Royal Train, and then taken in
a carriage procession to Buckingham Palace. Also used for the Royal Train to
Tattenham Corner on Derby Day.

I think it still is used for Royal trains - I have certainly seen one at
the platform within recent years, dropping off some international bigwig
who had, presumably, arrived at Gatwick.

Platform 1 could be closed off from platform 2 by the folding gates along
the length of the platform. It was certainly used for commuter trains after
the 1967 timetable alterations.

As, indeed, it often is today!
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 18 December 2004