Both Battleships and Battlecruisers were equipped with large calibre naval guns (the term calibre refers to the internal diameter of the gun barrel). At the start of the twentieth century, naval guns were of 12 inch calibre. By World War Two, naval guns were of calibres 14, 15 and 16 inch. The larger the calibre, the more destructive the shell it fired! Although confusion exists around the word calibre, as American naval guns can be referred to as 16 inch 45 calibre (found in the South Dakota class battleships), and also 16 inch 50 calibre (found in the Iowa class battleships). In this usage, calibre really refers to the length of a naval gun's barrel: as 16 times 45 equals 720 inches (60 feet), whilst 16 times 50 equals 800 inches (66.67 feet). The longer the barrel, the more powerful the naval gun. As a longer gun barrel, results in a 'fired shell' that is more aerodynamically stable - with a longer target range being possible. The battleships of World War Two, featured gun turrets with two, three or four gun barrels - with turrets usually arranged two forward, one back (for the allies).
Here we can see the two sternmost 15 inch naval gun turrets of HMS Hood (turret X is on the left, turret Y is on the right):
Whilst the roofs of these gun turrets were not decorated (with turret markings), both were located on a 'very wet deck' (the quarterdeck) which was usually awash 'when at sea'. Turrets X and Y did not partake in the opening stages of the Battle of the Denmark Strait - as their 'arcs of fire' were limited by Hood's approach angle (on Bismarck). It is with some irony then, that turret X 'appears to have been' fundamentally involved with the explosion that tore HMS Hood in half - with the fatal explosion 'likely originating' in one of its magazines (either shells or cordite). In any case, it is believed/known that the hull form area located around/near turret X (and its barbette) 'utterly disintegrated' during the explosion. Even so 'it took a while to realise' at Hood's helm!
Here we can see the stern deck area of HMS Hood. What I most liked about Hood's stern profile, was the fact that she had a matched pair of naval gun turrets, mounted astern:
Later battleships (including both American, and Japanese), would only have a single gun turret, mounted astern. I feel that the matched pair (in Hood), catered for a more balanced profile - both in terms of her appearance, and in terms of her firepower. Hood's stern deck, was an interesting area of contradiction! For on her Empire Cruise (when she sailed the British Empire), was this area often where the VIPs (such as Royalty) were entertained. With the wooden handrail ladders (middle-bottom right), leading to the Admiral's Day Cabin - came much pomp and ceremony. And yet, when Hood was at sea, even in a fairly calm sea, was this entire stern deck area, often awash with sea water! The stern deck had been designed too low in the waterline. Yet, there is some irony here. For in the wreck of HMS Hood (at the bottom of the North Atlantic), is it the stern deck and it's flag pole, that stand up from the sea bed, as if in salute.
The most important part of a battleship, has always been it's primary armament naval guns:
In the case of HMS Hood, these were 15 inch calibre - and are regarded, as some of the best naval guns, that were ever fitted to a battleship. Every single sailor, and every single system on-board HMS Hood, was there to serve these guns - to ensure that they could open fire: at the right range, at the right time, and at the right target! They were the most heavily protected part of HMS Hood - with turret face armour being 15 inches thick. The turrets sat atop the barbettes (the vertical cylinders), that were themselves protected by armour, of up to 12 inches thick (thereby protecting the shell supply chain). Hood's two forward naval gun turrets (referred to as A and B), are also somewhat unique in their decoration. At this time, A turret carried a red circular flagship marking - and B turret carried her Spanish Civil War marking (the blue/white/red stripes). Towards the back of each gun turret, is it's local control range finder - which adhered to a general rule: the wider the better, as a wider range finder, tended towards increased target accuracy.