layover - London - time for quick tour?
 

How long of a layover (at Heathrow) would we need to have time to take one of those double-decker bus tours? Impossible?

I would say a minimum of 8 hours. Unfortunately - if you are coming from North America, many transatlantic flights land very early in the morning so the first few hours are wasted if you want to do a double decker bus tour.

But w/o adjusting for early AM landing here are some reasonable times: Arrive at LHR (or Gatwick), taxi/unload plane = 30 minutes; walk to terminal and clear immigration = 20 to 45 minutes; travel into central London (including walking to train or tube and waiting for the next train) = 30 to 60 minutes; catch tour bus and take the full loop w/o getting off = 2 hours (add about 30 minutes for each place you get off the bus); travel back to airport = 30 to 60 minutes; check-in and clear security = 2 hours.

So with the longest estimates you are talking about a little over 7 hours. If you can give yourself 8 or 9 hours you would have plenty of time.

We hit the tube (metro) by the airport and took a quick tour of the British Museum. The new courtyard greenhouse is fabulous. The exhibits, as usual are fascinating. Got on the tube about 1:30-
about 35 minutes to desired station- short walk to museum- no charge for entry-spent about 2 hours at the museum-and back to the airport by 5:45.
I do want to warn EVERYBODY that Heathrow is a zoo. You need at least 3 hours from arrival at the door to seating on your plane. If you have to change terminals, that can take over an hour. Includes a bus ride, 2 security checks at the second terminal and at least one at the first.

Thanks. Good details. Also the note about giving yourself 3 hrs at Heathrow!

Heathrow Express to Paddington Station,get the 15 Bus to Tower of London (Tower Hill)which goes down Oxford Street,Piccadilly Circus,Trafalgar Sq(for Buck House,Horseguards Parade,Downing Street,Westminster Abbey,Big Ben, Nelsons Column,Covent Garden)The Strand,Royal Courts of Justice, St Pauls Cathedral,The Monument,Tower of London,Tower Bridge.
Buses every 15 mins or less.Get the Circle line(UNDERGROUND) at Tower Hill for a quick ride back to Paddington. Station.