Editing Renown-class battlecruiser (section)

===Armour===
The armour protection of the ''Renown''-class ships was similar to that of ''Indefatigable''; her [[waterline]] [[Belt armor|belt]] of [[Krupp cemented armour]] measured {{convert|6|in|mm|0}} thick amidships. It ran from the midpoint of "A" barbette to the midpoint of "Y" barbette, a length of {{convert|462|ft|m|1}}, and was {{convert|9|ft|m|1}} high. [[Strake]]s of three-inch armour aft and four-inch armour forward continued the belt towards the ends of the ship, although neither reached the bow or the stern. The strakes were enclosed by transverse bulkheads of the same thickness. For much of the length of the main belt there was an upper belt of high-tensile steel, {{convert|1.5|in}} thick, intended as splinter protection.<ref name=r13>Roberts, pp. 106, 113.</ref>

The gun turrets were {{convert|9|in|mm|0}} thick on the face and front sides, {{convert|7|in|mm|0}} thick on the rear side plates while their roofs were {{convert|4.25|in|mm|0}} thick. The barbettes were protected by {{convert|7|in|mm|0}} of armour above the upper deck, but it thinned to {{convert|4|-|5|in|mm|0}} below the deck. The conning tower sides were {{convert|10|in|0}} thick and it had a three-inch roof. The walls of the [[Glossary of nautical terms (A-L)#communication tube|communication tube]] were three&nbsp;inches thick. The torpedo control tower had 3-inch walls and a 1.5-inch cast steel roof.<ref name=r13/>

As designed the high-tensile-steel [[deck (ship)|deck]]s ranged from {{convert|0.75|to|1.5|in|0}} in thickness. After the [[Battle of Jutland]] in 1916, while the ships were still completing, an extra inch of high-tensile steel was added on the main deck over the [[magazine (artillery)|magazine]]s. Despite these additions, the ships were still felt to be too vulnerable to plunging fire and each ship was refitted in Rosyth in 1916–1917 with additional horizontal armour, weighing approximately {{convert|504|LT|t}}, added to the decks over the magazines and over the steering mechanism.<ref>Burt, p. 294.</ref>

The ''Renown''-class ships were fitted with a shallow [[anti-torpedo bulge]] integral to the hull which was intended to explode the torpedo before it hit the hull proper and vent the underwater explosion to the surface rather than into the ship. However, later testing proved that it was not deep enough to accomplish its task as it lacked the layers of empty and full compartments that were necessary to absorb the force of the explosion.<ref>Roberts, p. 111.</ref>