That really does not address the short coming.
But first the supposed difference between turret centric and masthead centric fire control:
In WWII naval fire controls, there are 3 components:
1. Director - which the officer in charge of gunnery use to designate targets to his guns
2. Range finder - Which receives instructions from the director on which target to look at, and determine the range to that target, as well as the range to any shell splashes that lands around the target.
3. Fire control computer - which receives continuous bearing input from the director, and continuous range input from the range finder, and computes a mathematical model of the absolute future movements of the target. It also receives inputs from the ship's own compass, knotmeters, etc, to compute a mathematical model of the absolute future movements of own ship. It also receive input from artifical horizon reference to determine the ship's pitch and roll, and generate a continuous stream of instructions to the gun turret on how to achieve correct lead angle and elevation to compensate for ship's own role and pitch to hit the target.
A director and range finder could really be anywhere. In all battleships of WWII, there are directors and range finders high up in the superstructure for primary control in long range battles, where a high location ensures line of sight over the curvature of the earth to enemy, and there are backup directors and range finders in each of the main turrets, so each turret can undertake local control of itself, or function as backup controler for all the other turrets. In a pinch, it is also possible to use the directors and range finders for secondary battery to feed the fire control computer for the main guns.
What is more, any director can pair with any range finder as situation requires to feed data into the fire control computer. They don't have to be next to each other. This is true for all WWII battleships, Japanese, German, British, or American. If all the main gun range finders were out of commission, but a main gun director is still in service, the main main gun director can pair up with the range finder in a secondary turret to continue to feed useful information to the fire control computer.
It so happens the British and Americans believed very long distance battles where the enemy is visible only from the masthead (30Kkm+) is unlikely to be decisive. So there was no need to accept the added top weight of putting a heavy long baseline range finder so high up in the superstructure. That's why on British and American battleships, while there are directors high up in the superstructure to ensure a panaramic view of the battle so targets can be better chosen, there was only a short baseline light weight range finder up top. The reason is the belief that at decisive battle range, the enemy will be visible from the turret and a big range finder in the turret would be much better protected than a big range finder at the top of the mast.
The Germans and the Japanese, on the other hand, thought the battle could in fact be decided at very long range with plunging fire, where the enemy would only be visible from the masthead. This is why their battleship puts their longest baseline range finders high up on top of their conning towers, to ensure best possible fire control input when the enemy is still hidden behind the curvature of the earth when viewed from turret level.
How each side's expectation corresponded to reality as discovered in WWII is the subject for another discussion. Suffice it to say Japanese pre-war doctrine call for fire to be opened at 34km, but Japanese expectation of hit rates at 30kms turned out to be higher than any that was ever actually achieve in battle condition by any one at 17-19 kms.
But the point here is the general layout of the fire control systems of Japan, Britain, US and Germany wasn't all that different, just different emphasis on range.
Now back to the issue of indexing. The Japanese system is poor simply because if the control needs to be transfered from one director to another, it takes a long time to do it. Furthermore, the new director, if it had already been tracking an enemy target and have been feeding data into the fire control computer, must now stop, pivot around to point dead ahead or dead astern and weight until all the gun turrets also line up in their neutral positions, before it can be trained back onto the target and begin a new firing solition. So any soliution the firing control computer had been working on it not lost, and it has to start over again. It doesn't matter if the director being transfered from and the one being transdered to is on the masthead, or in one of the turrets.
It also makes it impossible for the Japanese to have different directors simulataneously track different targets and continuously imporve firing solutions to multiple targets at the same time, and switch the entire main battery from one target to another as tactical situation needs. Instead they must split the main battery into several sub battery to simulataenously engage different targets separately.
The Japanese and Germans also emphasized dispersion and redundancy more than British and Americans. The Yamato had no less that 6 different backup main battery directors on her superstructure, one on top of the massive 15m range finder at mast top, two half way up the tower mast on each side, one over rear 10m range finder, and two on either side of the under the 10m range finder tower, in addition to the three in the main turrets, for a total of 9 main battery directors, compared to 5 on British and American battleships.
It is a pity how Yamato was given so many redundant directors to ensure combat effectivess after suffering damage, but adapted a system that made switching from one director to another so laborious and disrupting.
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