ZF uses topology optimization to develop a Ship Gearbox Housing (link).
Optimization results (blue) and user interpretation
The design combines thrust bearing into the gearbox. Thrust bearing deals with the loads that arise from the propeller (or jet). So loads are huge. The special criteria that is wanted here is the displacement to be parallel so that the bearing is not abused. As seen from the results and interpretation above, optimization yielded heavy reinforcements on the side that is far from wall. The near wall side is lightly reinforced, so that the displacement remains parallel.
CAD interpretation of the optimization result
However as seen from the CAD interpretation, the near wall side is heavily reinforced, which seems contradictory to the parallel displacement requirement.
The casing in real life