Heathrow Airport is one of the largest employment sites in London with over 76,600 people working within the Airport boundary creating gross value added (GVA) of almost £3.3 billion
http://www.airpor****ch.org.uk/2014/...-charge-rises/
With 231 gates, that's over 300 employees per gate or over 150 employees per gate per shift assuming an average of 2 shifts.
Where are all these employees? I haven't noticed anywhere near 150 employees per gate.