HMS Hood was an Empire Ship that sailed the world. As such, her upper decks were an interesting mix, of both peacetime and wartime:
For me, the peacetime is represented by the variety of smaller boats that she carried on-board. I believe that these were used when she was in port, or when she had anchored off some tropical island, for some rest and relaxation (for her sailors). Yet, she was still a warship, with the armament to match! Here we can see: a 5.5 inch naval gun (lower left), a 4 inch high angle anti-aircraft gun (middle-bottom), and a quadruple 0.5 inch anti-aircraft gun (middle-bottom right). Now, I've heard it said, that sailors don't have a fear of heights! Hood's main mast, would appear to test this theory - with the mast's ladders being used to gain access, to both lookout posts, and wireless radio equipment. The long horizontal boom, that stems from the base of the main mast, is the main derrick, which was 65 feet long! I believe this was used, to lift both the smaller boats, and other heavy equipment (such as ammunition crates).
The highest observation point located on-board HMS Hood, was her spotting top:
It is here, that her look outs would have scowled the seas, looking for the tell tale glimpse, of an enemy vessel (in a time before radar). The tripod mast on the back, is where Hood's wireless rig was attached (the six horizontal lines coming in from the top left). Both structures, were supported by a single starfish - the black metallic structure, that's located underneath. One of HMS Hood's three survivors (from when she was sunk), was actually stationed in the spotting top - surviving because he was washed through a window, as everything else around him sunk!
Here we can see, what I regard as HMS Hood's front conning tower:
Though technically the term conning tower, only applies to the elliptical structure on the front (with the rest being superstructure). The conning tower itself, was concerned with the aiming of the primary armament 15 inch naval guns. It was protected by armour of up to 11 inches thick: to ensure that Hood's 15 inch naval guns, could be aimed and fired, even in the heaviest action. The superstructure itself, was concerned with both the manoeuvrability of HMS Hood (such as steering and navigation), and further fire control (for both the secondary armament, and anti-aircraft guns). The superstructure was soft (aka thinly protected), to save armour weight. It included such equipment as: search lights, 3 pounder saluting guns, quadruple 0.5 inch anti-aircraft guns, eight barrelled two pounder anti-aircraft pom-poms directors, 5.5 inch secondary armament directors, evershed transmitters and air defence platform equipment (e.g. binoculars).
Here we can see the details of the midships area of HMS Hood:
Of particular interest are: i) The eight barrelled 2 pounder anti-aircraft pom poms gun. ii) The 4 inch high angle anti-aircraft gun. iii) One of the secondary armament 5.5 inch naval guns (with it's protective shield). iv) The smaller crane derricks, which were helpful for lifting both ammunition, and smaller boats. v) The torpedo look out control towers. Which I believe, would issue just one command: take evasive action! vi) Venting for the boiler rooms (located at the base of the funnels, just under various life rafts). vii) The smokestacks themselves, which vented waste gases and heat, from Hood's boiler rooms. There's an unproven theory, that the shell that sunk HMS Hood, may very well have penetrated one of these, and detonated the oil fuel (inside her boiler rooms).
Here we can see the look out posts for the various crew members of HMS Hood, that were tasked with looking out for enemy aircraft:
Most of these involved some sort of optical sight (such as binoculars), whereby it's operator would locate enemy aircraft, then obtain various measurements (such as bearing and elevation), which in-turn, was fed into several (analogue) fire control computers, which in-turn was relayed to the gun operators (who opened fire). Hood's anti-aircraft guns, were also capable of local control, when (for example) such bridge tower directors had been knocked out.