The Yamato class are best remembered for their massive guns and thick armor. Speed is the last thing on anyone's mind when discussing these dreadnoughts.
However, Japanese designers put considerable thought into the speed of the class.
The most famous feature was the bulbous bow.
Contrary to popular belief, the bulbous bow was not a Japanese invention. However, they did introduce what was the most radical design yet, one that offered superior performance to her contemporaries.
The effect on performance was significant. At top speed, the bulbous bow reduced the amount of power needed by about 8% or 12,000 shp. Meaning that without the Bow, the Yamato class would need roughly 162,000shp to reach her maximum speed.
The Yamato hull was also highly optimized for speed.
Japan conducted extensive testing on various hull designs. These tests involved everything from tank models to full size tests using the then demilitilarized Hiei.
The result was the interesting coke bottle hull shape.
Despite the wide beam of 128' (38.9m), the hull form allowed water to easily move around the hulll.
This reduced the amount of power needed to push so much ship through the water.
Even the stern was optimized for efficiency. The hull gradually tapered towards the stern before suddenly ending in an almost miniature transom stern. This was also heavily tested and based on full scale trials.
(Credit to Yamato Museum)
Even the rudder design was chosen in the bid for performance.
Japanese designers opted for twin rudders in an inline arrangement (A trick used by other navies as well) to help reduce water resistance.
(Ditto)
The result of all this development was an impressive top speed exceeding 27 knots. This was equal to or just under that achieved by all of her contemporaries at the time of her entry into service. Impressive considering Yamato displaced about 30k tons more.
Sadly, due to the destruction of records. We won't know exactly how fast the class could reach. By forcing the engines, she might have picked up an extra knot or two of top speed.
Still, let it be said that the Yamato class was a masterpiece of Japanese naval design. Truly no expense or effort was spared to squeeze every drop of performance from the hull.
Alright! Everyone has been taking wild guesses about what I consider a simple, yet brilliant design feature on the Yamato class. However, everyone was thinking big!
So what could this mystery thing be? Well, before we get to it, we need to first talk guns and loading them!
1
As battleships evolved, they increasingly made use of larger, more powerful guns.
In turn, these guns required larger turrets to house them. However, other things also increased in size along with the guns, namely the propellants and loading mechanisms.
2
As naval guns got larger and the shells they fired got larger, the propellants needed to propel them down the barrel got proportionately larger as well.
Larger guns typically needed multiple bags of propellant. Even divided up, these individual bags could be quite heavy.
Alright, the United States and its flight deck fantasies Part 1: The Flight Deck Cruisers
The Washington Naval Treaty, as well as the later London Naval treaties, were an incredible achievement for halting (temporarily) a growing naval arms race.
The German and Japanese navies are best known for their attempts to circumnavigate treaty restrictions. However, this does not mean other countries were playing by the rules.
The United States Navy was also looking for ways to circumnavigate treaty restrictions.
One of the more notable attempts to do this was through hybrid cruiser-carriers. Cruiser-sized warships with a large flight deck and a cruiser-level armament.
Such warships were desired for a variety of reasons.
In an early post, we briefly touched upon high velocity, shallow arc and lower velocity, higher arc guns.
While discussions on muzzle velocity are typically examined from a range, accuracy, or penetration angle, one other factor existed that played an equal if not larger role.
This factor is barrel wear. Something that influenced naval design for several navies.
The forces required to force a heavy naval shell through a barrel are tremendous. The intense heat and pressure places a great deal of strain on the barrel
Each shell that is forced down the barrel strips a tiny bit of the barrel along with it. This damage is typically towards the breech of the gun, concentrated towards the start of the rifling. However, successive shots allow the damage to extend further down the barrel..
One of the greatest ships you never heard of. Shinshū Maru was a amphibious assault ship developed by the Japanese before WW2.
To call her innovative would be an understatement as the ship was a collection of advanced features.
The most advanced of which was a large, floodable well deck. This allowed her to rapidly deploy her landing craft during amphibious operations. On the subject of landing craft, she could carry about fifty in addition to four gunboats.
Her massive superstructure was originally intended to function as a hangar, allowing her to handle her own floatplanes to better coordinate landing operations. However she lost her catapults prior to completion and never carried her aircraft.
The forward 6"/47 Mark 16DP guns aboard the cruiser Worcester.
The Mark 16DP saw the earlier Mark 16 (Cleveland & Brooklyn classes) guns be mated to a new turret and greatly enhanced shell handling equipment.
This allowed the Mark 16DP to retain its powerful anti-ship performance, while granting it autoloading capability and any angle loading. The mounts also featured powerful motors, granting fast traverse and elevation rates.
This made the Mark 16DP one of the first truly successful 6" dual-purpose guns to see service.
However, the weapon was not without drawback.
It was extremely heavy. It was also let down by a complicated dual feed loading system that hampered rate of fire and was unreliable.