Diesel engines cannot work without oxygen, so how do diesel submarines operate when they're underwater? Their propulsion system accounts for this limitation.

The once-almighty Mitsubishi Motors may have relegated themselves to building cheap small cars and Nissan-derived crossovers, but it was an indomitable powerhouse of innovation back in the day.

While diesel engines don't need spark plugs, they do need air ventilation for proper combustion. This is a problem for vessels traveling underwater, such as submarines. Yet diesel submarines exist and ...