Complex sentence: Her propeller was designed to be hoisted up into the stern of the ship to reduce drag while under sail; the largest hoisting propeller ever made, it required 600 men to raise it into the stern.
Split into simpler sentences: Her propeller was designed to be hoisted up into the stern of the ship to reduce drag while under sail, and was the largest hoisting propeller ever made. It required 600 men to raise it into the stern.