Thanks 750XL, interesting but something still does not add up. A quick search for B4 weights:
EOW 79 000 kg (174 200 lb)
MZFW 130 000 kg (286 600 lb)
MTOW 170 500 kg (375 900 lb)
MLW 140 000 kg (308 600 lb)
What were they doing there with just six tons left sloshing in the tank ?