Short answers, pulled from the story.
The first iron steamship to go to sea was the 116-ton Aaron Manby, which crossed the English Channel in 1822 and arrived in Paris on the 22nd of June. This vessel carried passengers and freight to Paris at an average speed of 8 miles per hour, marking a pivotal moment in maritime history.
The SS Great Britain was launched in 1843 and became the first iron-hulled screw-driven ship to cross the Atlantic. It was the first ship to combine iron hulls with screw propulsion, making it by far the largest vessel afloat at the time.
The first ship fitted with triple expansion engines was the Propontis, which was launched in 1874. It was later followed by the SS Aberdeen, which went into service on the route from Britain to Australia with improved boilers running at 150 psi.
The SS Titanic was the largest steamship in the world when it sank in 1912. A subsequent major sinking of a steamer was that of the RMS Lusitania, which occurred as an act of World War I.
The Queen Elizabeth 2 was launched in 1969 and was the last passenger steamship to cross the Atlantic Ocean on a scheduled liner voyage before it was converted to diesels in 1986.
As of August 2017 the newest class of Steam Turbine ships are the Seri Camellia-class LNG carriers built by Hyundai Heavy Industries starting in 2016. These ships comprise five units and represent the current state of steam turbine technology in the commercial market.