HMS Northumberland was the last of the three armoured frigates built for the Royal Navy during the 1860s. She had a different armour scheme and heavier armament than her sister ships, and was generally regarded as a half-sister to the other ships of the class. The ship spent her career with the Channel Squadron and occasionally served as a flagship. Northumberland was placed in reserve in 1890 and became a training ship in 1898. She was converted into a coal hulk in 1909 and sold in 1927, although the ship was not scrapped until 1935. Design and description The Minotaur-class armoured frigates were essentially enlarged versions of the ironclad with heavier armament, armour, and more powerful engines. They retained the broadside ironclad layout of their predecessor, but their sides were fully armoured to protect the 50 guns they were designed to carry. Their plough-shaped ram was also more prominent than that of Achilles. Northumberland was long between perpendiculars and had a beam of and a draught of . The ship displaced and had a tonnage of 6,621 tons burthen. Her hull was subdivided by 15 watertight transverse bulkheads and had a double bottom underneath the engine and boiler rooms. The ship was considered "a steady gun platform, able to maintain her speed in a seaway and satisfactory in manoeuvre". She was authorized a crew of 705 officers and ratings, but actually carried 800 men. Propulsion Northumberland had a two-cylinder trunk steam engine, made by John Penn and Sons, driving a single propeller using steam provided by 10 rectangular fire-tube boilers. It produced a total of during the ship's sea trials on 15 September 1868 and Northumberland had a maximum speed of . The ships normally carried of coal, but had a maximum capacity of , enough to steam at . Originally designed with three masts, Northumberland was fitted with five masts until her 1875–79 refit when two were removed and she was re-rigged as a barque. Northumberland only made under sail, mainly because the ship's propeller could only be disconnected and not hoisted up into the stern of the ship to reduce drag, the worst speed of any ironclad of her era. Admiral George A. Ballard described the Minotaur-class ships as "the dullest performers under canvas of the whole masted fleet of their day, and no ships ever carried so much dress to so little purpose." Armament Unlike her half-sisters,