Most airports which can accommodate 747/767/777/787 and Airbus equivalents use hydrant refuelling which means a pot embedded somewhere on the stand, which a dispensing truck plugs in to then attaches a hose to the aircraft. The dispensing truck has 2 functions - filtering the fuel and measuring the volume dispensed. It may well be that the aircraft is positioned so that refuelling can only take place under the left wing. Most airports are designed with more than one pot per stand. In the case of Gatwick, for instance, some Piers are set up for multiple different aircraft sizes/types so when initially laid out, pot positioning was carefully gone in to. Digging up the stand to reposition pots would be a massive undertaking. The dispensing truck has only very limited range of movement.
A 747 would take at least 3 oversize fuel bowsers to refuel, and several hours, just not viable. Fully laden it would be about 238,000 litres of fuel.
Fuel is delivered from the fuel farm via the underground hydrant system at 12 x atmospheric pressure. If the connection between the dispenser and the pot were to be disrupted, i.e. a vehicle driving in to it, the resultant jet of fuel would reach about 50 metres, before the automatic detectors noticed the sudden drop in pressure and cut the pumps off. I can think of only one instance where this has happened, in South Africa, I believe, many years ago. There is an emergency hydrant cutoff button at the head of every stand.
One amusement is that any disruption to the electricity supply to or within the fuel farm will shut off the hydrant system. Many years ago, in the fuel farm at a busy London airport, the fire alarm would go off, shutting off all the hydrant electrical system and throwing the airport into complete chaos and severe delays. The cause was traced to a toaster in the crew rest room kitchen setting off the smoke detector. Toasters were banned, no more chaos.
TOO