The American 'twin barrel' 5 inch naval gun is regarded as 'one of the most successful naval guns' of all time:
Part of its success, comes from the fact that the US Navy standardised the 5 inch gun, for use on both battleships and smaller warships (such as cruisers and destroyers). This made shell logistics 'so much simpler'. On a battleship, the twin 5 inch was only ever a secondary armament (for use against aircraft and surface targets). Whilst on cruisers and destroyers, the 5 inch 'was usually' the primary armament - with up to eight turrets being installed (for example) on the 'light cruiser' USS Atlanta (which featured six centreline turrets 'for stability reasons' and two wing turrets 'for maximising' anti-aircraft firepower). The 5 inch gun was heavily used throughout World War Two, to defend the American warship fleets 'in the Pacific'. When used to defend against enemy aircraft, several turrets would operate together, using barrage fire (the idea being: not to target the enemy aircraft directly, but rather 'target the area' that the enemy aircraft was in) and destroy the aircraft with shrapnel 'exploding outwards' from the 5 inch shells (which were equipped with proximity fuses). As an anti-aircraft gun, the twin 5 inch 'more than proved its worth', and it was a gun turret that would not be easily mothballed - even after World War Two had finished (in 1945) ... When the Iowa class battleships were reactivated (in the 1980s'), the venerable twin 5 inch dual purpose gun, was retained as part of their armament - although with only six turrets (as opposed to ten turrets) to make room for newer 'more modern' missiles.
The early World War Two modifications of HMS Hood, resulted in Hood's 'boat deck' (also called her 'shelter deck') being outfitted with seven 4 inch 'twin barrelled' anti-aircraft guns:
This was something of an 'austere makeover' that aimed to increase Hood's anti-aircraft capabilities. To 'make space' for installing these guns, all of Hood's single barrelled 4 inch anti-aircraft and 5.5 inch naval guns 'were removed' - although facilities (such as their magazines and 'shell supply lines') were enhanced to support her new guns. These modifications were carried out 'more for speed' than for robustness reasons - as the entire 'boat deck' could really be considered as a target for incoming shells! This issue was further compounded, by the fact that 'ready use' ammunition lockers were installed 'next to and near' each anti-aircraft gun mount. During the Battle of the Denmark Strait, a boat deck fire 'wreaked havoc' amongst the ammunition that was stored in these.
The hull form in this area, was protected by the thickest belt armour - of up to 12 inches. The idea was a simple one: important machinery (such as the boilers and engines), were enclosed in the thickest belt armour, so that warships like Hood, could take punishment under fire, and still maintain a manoeuvrable gun platform (aka the ability to fire their primary naval guns). Unfortunately, Hood's machinery spaces were considerably long (about 391 feet, 45.5 percent of her length), and she had been designed in a time, when plunging shell fire (which would penetrate the deck), had not really been considered. Hence, the midships deck armour was way too thin, and what armour there was (of up to 3 inches thick), was spread over too small an area! Such short comings, were not known to her sailors - who believed her to be the greatest warship in the Navy, and she was :) This view also best showcases Hood's secondary armament - her twelve 5.5 inch naval guns. These were designed to engage surface targets only, such as destroyers - which could have easily launched torpedoes at her. These guns, would also have supported the primary 15 inch naval guns (when in range).
Hood - Life and Death of a Battlecruiser - Roger Chesneau - Part One
Something of a first for me - as I actually read this Battleship Book from cover to cover within a day and a half:
It helped that the book is on HMS Hood. It helped that the book is a good read. It helped that the book is packed full of so much information, that those pages just kept turning! I feel that this book really comes in three parts (although it's spread across six chapters): Genesis and Design, Peace and War, Death and Inquest. I shall now consider each of these in turn. Analysis One - Genesis and Design. HMS Hood was born from the Battleship race - specifically the need for speed (at the expense of armoured protection) that gave rise to the Battlecruiser concept. This book goes to great lengths to highlight the fact that HMS Hood was originally designed as a Battlecruiser (e.g. through it's use of design tables), and that on the very day that she was laid down (31 May 1916), that all work was suspended - owing to the Battle of Jutland, which had seen three such earlier Battlecruisers blown apart (after suffering magazine explosions caused through plunging shellfire). In all three cases, was the level of horizontal armour protection called into question. It is here that HMS Hood was transformed into something more akin to a Fast Battleship, as her deck armour was gradually increased (e.g. from 1.5 inches, to between 2-1 inches, to between 3-1 inches - the thicker armour was used closer to Hood's magazines). This book not only considers these developments, but also explains Hood's anti-torpedo protection, machinery (such as the Brown Curtis turbines and Yarrow oil-fired boilers), primary armament (including elevation increase), secondary armament (such as why it was not case-mated) and fire control (of primary, secondary and anti-aircraft guns). Analysis Two - Peace and War. HMS Hood was commissioned into the Royal Navy on 15 May 1920. World War Two started on 1 September 1939. This meant that HMS Hood spent most of her life as a Peacetime Warship of (just over) 19 years! The Peacetime chapter shows very clearly how the reputation of The Mighty Hood was earned, especially in the eyes of the public, who (even now) I feel, would be in awe of this stunning warship (if she sailed into port today). Much of this reputation was earned during the famous World Cruise (which saw HMS Hood travel over thirty-three thousand miles to bolster Britain's relationship with it's Empire). Even so, it is important to remember that HMS Hood was still a warship - which meant that her crew participated in regular gunnery exercises (by herself or with other vessels), as she sailed between the various ports of her World Cruise. Thus, when War broke out - was HMS hood (and her crew) available to participate in front line duties. Some of this was to become routine, such as: i) The various skirmishes into the Atlantic to intercept perceived threats (e.g. preventing the break out of smaller German warships). ii) Convoy duty (e.g. helping to protect Iron Ore en-route from Norway to Britain, and helping to protect the transport of troops from Canada to Britain). Some of this was absurd - such as when HMS Hood (and other British warships) were ordered to sink the entire French Naval Fleet at Mers-el-Kbir (North Africa). Whilst I understand the reasons behind this attack (fear of the French fleet falling into German hands), it seems totally crazy that allies would attack each other like this (when they should only have been concerned with defeating Germany). In any case, the book makes one point very clear (both through text and images) that Hood was heavily used both up-to, and during the early stages of World War Two, and as such - the usual polished ship-shape decks were soon covered with the grime of war.