Perusing Flightaware I have noticed that freight flights out of Anchorage (FDX/UPS/EVA/WORLD/SHANGHAI) are making 4500nm+ trips (ZSPD/VHHH/RCTP...etc) and I know that the MD-11F has some legs provided there is a cut in payload but does anyone have a rough idea numbers wise as to how much freight these aircraft are taking off with?

Thanks!