Complex sentence: The metal bulkheads presented problems with acoustics and soundproofing that were originally solved by lining the walls with mattresses and blankets from the crew's bunk beds, which meant none of them could sleep during the day.
Split into simpler sentences: The metal bulkheads presented problems with acoustics and soundproofing, that were originally solved by lining the walls with mattresses and blankets from the crew's bunk beds. This meant none of them could sleep during the day.