Thanks Mr. 244. You certainly do and definitely very observant! In researching these large Korean built container vessels, I am reasonably certain that it is high voltage. Most likely 6.6 kV. With the approx. 16 MW of power generation I think the vessel may be fitted with about a 1000 reefer outlets (7-8 kW each). So, many transformers required for reefers and a couple (100% redundant) for the essential loads. Essential loads for operating the main engine and all other consumers including the Bridge, accommodation, galley, etc will be around 1.5 MW only. Bow thruster (3000 kW) most likely is same voltage and directly fed from the high voltage board.
Just thinking out load here. I think they had a case of double jeopardy (concurrent equipment failure) or a consequential effect that knocked out critical equipment. Blackout due to a fault (most likely electrical) and in turn this blackout resulted in the steering gear damage. The quick recovery from the blackout corroborates the electrical fault theory. And the ME electronic engine where there is no lost time in camshaft/reversing links/starting air distributor to re-position, reversing is almost instantaneous. Braking air and as soon as the prop turns astern about 15 rpm air off and fuel on. Excessive black smoke is due to turbos not yet upto speed to provide sufficient air for the demand rpm. You see the timing of the first blackout also seems reasonable when the Bridge would announce they are done with the Thruster. And when they get the ME started and realize no steering they ask for the BT again as a last ditch effort. And the second blackout when they energize the BT breaker in the engine room.
Generally in the marine industry no failure modes analysis or workshops are conducted and for sure double jeopardy or freak incidents will not be considered. Got to be patient for the NTSB report!
BTW, I also saw a news item about Hyundai shipyard with an approval in principle from DnV GL class for a new electrical generation and distribution design. Most likely they may revert to 440V rather than the high voltage.