Complex sentence: The primary purpose of funnels on steamships were to allow smoke, heat and excess steam to escape from the boiler rooms, additionally in the event of a ship floundering ladders inside the funnels provided escape routes for the stokers and engineers once the watertight doors were closed.
Split into simpler sentences: The primary purpose of funnels on steamships were to allow smoke, heat and excess steam to escape from the boiler rooms. Additionally, in the event of a ship floundering, ladders inside the funnels provided escape routes for the stokers and engineers once the watertight doors were closed.