Marine Log reports an additional refinement that is being applied to the software control for Azipods. Sounds a bit like toe-in on your car. And its something you can’t adjust dynamically with conventional shafts.
“Called ABB Ability OptimE – Toe Angle Optimization for Propulsion, the solution automatically selects the optimal steering angle for the Azipod system. ABB says that with OptimE, further fuel savings of up to 1.5 percent can be achieved depending on a ship’s operating profile. These savings are in addition to Azipod propulsion’s ability to cut fuel consumption by up to 20 percent when compared with a traditional shaftline setup.”
I would add that conventional propeller shafts are a weak point in ship damage survivability as well, in that, when damaged, they can open up avenues for progressive flooding that may extend half the length of the ship.