River Plate: conflicting track charts

From the Washington Naval Treaty to the end of the Second World War.
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tommy303
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Re: River Plate: conflicting track charts

Post by tommy303 »

Looking at Schmalenbach's schematics, once the target was designated both the appropriate director and the appropriate rangefinder were put on target and controlled by the computer/operators. It could be any rangefinder and any director, or any radar.
Yes. The communication between director and calculating center worked as a closed circuit. The director gave initial direction with observed enemy speed and course. The calculating center did its bit to convert all data into rate of change and sent back training and artificial horizon to the director, range finders, etc through remote power control. The director crew by detecting errors in train could then make corrections which were fed back to the calculating center.

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Dave Saxton
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Re: River Plate: conflicting track charts

Post by Dave Saxton »

Thank's Tommy,
dunmunro wrote:Track chart from the RNZN history:

Image


http://nzetc.victoria.ac.nz/tm/scholarl ... vy-c4.html
Thank's Duncan,

Its interesting how different people, in all good faith, can see the same events so differently. I'm more inclined to trust the German charts more in this case based upon:

)Exeter was essentially de- capitated early and couldn't accurately record what it was doing.
)The Germans should have a fairly accurate record of their own movements, courses, speeds...ect...
)The German shooting accuracy means their reported battle ranges were probably correct.
)The angles of fall of some of the hits on AGS support the ranges reported by the Germans.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.
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Dave Saxton
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Re: River Plate: conflicting track charts

Post by Dave Saxton »

So one can see them back to back:
Thorsten Wahl wrote:german scetch
Image

zoomable
https://plus.google.com/u/0/photos/1136 ... 4337291328
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.
ric_roc
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Re: River Plate: conflicting track charts

Post by ric_roc »

The available British plots of the River Plate engagement are hand drawn sketches, those do not seems to be be "official" Admiralty document but witness accounts.
Question 1: British Battleship and Battlecruisers were fitted with a plotting table in the Director Control Room, was it the same for the Cruisers? Was it an Elliot-Automation? Which version?
Question 2: Are the actual plotting map generated during the battle classified?
Question 3: Where is it possible to find documentation on the DCT of the HMS Exeter, HMS Ajax and HMS Achilles? Was the HMS Achilles (NZL) equipped with the same Fire Control Calculator than the Home fleet?
The documentation I found about British Fire Control is mostly for Capital ships. There are many versions, options and customizations. Field upgrades would also complicate the analysis. My sources are:
British Mechanical Gunnery Computers of WW II (Allan G. Bromley 1984)
Basic but useful schematics
Fire-control for British Dreadnought: choices of technology and supply (John Brooks 2001)
Extremely detailed and documented, mostly looking at WWI and the immediate following decade.

I am building a model for resolving gunnery in the early years of WWII and both books above are providing useful inputs! I am now have 2 separate resolutions:

#1 The acquisition of the target (where does the fire-control officer aim in respect of the actual position of the target) → (∂x1 , ∂y1)

#2 The dispersion of the salvo around the aiming point → (∂x2, ∂y2) + the angle of impact Θ. The target ship “zones of danger” (function of Θ) will be overlapped to the resulting X , Y

The British and German were having very different approach to target acquisition and I will tried to build accurate model with their intrinsic qualities and weaknesses.
pgollin
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Re: River Plate: conflicting track charts

Post by pgollin »

Alan Raven is writing a book on RN cruiser actions in WW2. I know that he has looked at all the available info for the Battle of the River Plate including the somewhat elusive report of HMS Exeter.
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