Thanks for the replies...

So another reason to go with carry-on luggage whenever possible.

Is it a general rule that bag drop does not open before check-in or do some countries (I do not expect a list) allow an early bag drop (as Heathrow does). I recall being able to drop off luggage in HK city centre early morning which was very convenient... The information on the BA site does not make it clear that Bag Drop only starts 3 hours before, here is the information in my booking (you might make an incorrect assumption that Bag Drop was available from online check-in?). Would be helpful if BA also stated how long before departure Bag Drop was available?

"ba.com online check-in opens 24 hours before departure and closes 1 hour before departure. You may check in on-line for this flight and print your own boarding pass. Please check in your bags at the Bag Drop. If you wish to collect your boarding pass at the airport, please go to a Self Service check-in kiosk before proceeding to the Bag Drop.

Self-service check-in not available.

Airport desk check-in opens AM flights - 05:45 on day of departure PM flights - 3 hours before departure and closes 1 hour before departure. Location - Terminal E, Departures Level, Desks 17-30"