B747 series beautifully over-engineered.
One of the design criteria, as I have been informed by those "in the know" was that the aircraft can always make it back to base, no single fault/failure should stop her.
Just FYI, the hydraulics had 4 engine driven pumps, 4 air/electric pumps as backup and 2 aux pumps - Sys #1 and #4 - for push back.
The rest of the systems were similarly engineered. Marvelous to operate this aircraft.