In the 747, while the airplane did have a loading calculation system which could determine CG as the aircraft sat on it's gear, it's not active or able in our airplanes. We do everything using a computer based calculation formula,and all crewmembers are required to show proficiency in using the system. We use dedicated loadmasters who plan, prepare, load, and verify what's on board, but because we operate to far-reaching locations where capabilities of the modern world aren't always available, we're required to be able to do it ourselves as crewmembers.