soc.history.war.world-war-ii

On Jan 29, 6:17 am, "Geoffrey Sinclair"
wrote:
> wrote in message
>
> news:6f78b388-e576-4c03-9c99-8f37d5250011@j20g2000hsi.googlegroups.com...
>
> > On Jan 27, 6:29 am, ken...@cix.compulink.co.uk wrote:
> >> In article
> >> <0873a2aa-bd8b-41a9-8e51-6d9f9508d...@c23g2000hsa.googlegroups.com>,
>
> >> eunome...@yahoo.com.au () wrote:
> >> > In fact the RN AAA was the most retarded of any major
> >> > combatant.
>
> >> The RN was behind the USN with heavy AA but ahead in light AA at the
> >> start of the war.
>
> > The RN may have had better guns but it didn't not have better fire
> > control for light guns.
>
> The trouble here is of course that things changed over the course of the
> war and it seems the worst of the RN is being selected as the base
> comparison.

First of all several posters made the claim that the RN was behind the
USN but ahead of all of the Axis in AAA Fire Control.

This is most certainly not correct, especially for the German systems
and it seems the Japanese and the Italians systems were more thorough
in some areas and it can be plausibly argued were better as well.

Certainly that is the statement made by the author of this article.
http://www.navweaps.com/index_tech/tech-066.htm

The context (check my post) being the more sophisticated systems for
bigger guns HACS, Mk 37, the German Dop L32 mounts.

In terms of the Medium AAA my comparison was purely within the USN/
RN. The Germans having a good stabalised mount but with a 37mm gun
that had good ballistics and and power but very poor rate of fire.

Now, HACS or 'High Angle Control System' as opposed to the 'Low Angle
system' used against surface targets was a key system for RN ships
from destroyers to battle ships since it controlled destroyer main
armament and heavy ship secondary armament (i.e. anything in the range
4.0, 4.5, 4.7, 5.2) when used in the AAA role.

The RN was the largest or second largest navy.

The HACS was certainly the more primitive system out of the equivalent
German and American systems so it's a good "base" for comparison.

I also argue that Modifications really improve HACS as much as you
infer either, as I will explain. Perhaps deficiencies with HACS were
filled in by good medium AAA.

Looking at the German systems one can see that eventually they had
either 20mm or 105mm guns with little sophistication in between.

Consider the challenge of long range AAA and how HAACs worked.

First of all the bearing and range of the target needs to be known.
This is fairly easy using an optical sight and stereo optical or
coincidence range finder.

Secondly its velocity (speed and heading) needs to be ascertained so
that this can be used in conjunction with ballistics data to solve
simultaneous differential equations so that an firing solution
( intercept point) and fuze setting time is calculated. Since the
shell might be in flight for several seconds during which the aircraft
might move around 1.5km this velocity estimate needs to be
accurate.

This is where HACS was very poor, yes modifications with radar were
made but they corrected only one of the two core limitations. At
least the final limitation wasn't resolved till 1945.

With HACS speed and heading had to be 'estimated' rather than
calculated automatically as full 'tachyometry' of continuously
measuring bearing, elevation and range in respect of time and a stable
gyroscopic reference to derive velocity were not inplemented in HACS,
not doubt there were instruments and techniques to assist the HACS
control officer in doing this but it got down to an estimate and but
in practice it seems to have been impossible to keep track of the
velocity changes of WW2 aircraft. HACS kept track of the aircraft
using the estimated data in case the ship turned or the aircraft
passed into clouds.

The USN and Kriegsmarine systems were fully "Tachymetric" ie velocity
measuring not just position measuring. The RN HACS at the beginning
of the war seems to have lacked rate gyros so that as the ship turned
accurate angular rate measurements could therefore not be made. Yes it
was able to plot on a graph paper the target aircrafts calculated
bearing during ships manoeuvres using the velocity estimate that had
been manually entered while the aircraft became obscured by cloud but
that was only after the uncompensated speed 'estimate' had been made.
To repeat the system was unable to take speed measurements by simply
tracking the range and bearing of the target or to calculate them as
it lacked the compensating gyro rate reference to do this as well as
the calculating mechanisms.

Later GR (Gyro Rate) Units and GRUB (Gyro Rate Unit Boxes: quaint RN
talk for the associated basic computer) were added. These took
inputs from the optical sight and combined it with range readings from
the 50cm wavelength type 285 radar that were semiautmatically entered
into the system to calculate speed and heading. (note the type 285
radar couldn't track the target it could only range it so optical
tracking was still necessary. The HAACS system still was unable to
automatically integrate optical range measurements into the GR/GRUB
though the use of radar range measurements bypassed this need in most
cases.

The lack of pure optical tachyometry probably would be a problem in
the case of effective jamming or littoral clutter or during amphibious
support.

Now there is another problem not dealt with by the 285 Radar and GR
Units/GRUB which now could calculate speed and the radar apart from
the fact that an all optical solution was not possible and this is
that the HACS and its new GRUB still can't directly calculate and
track height changes, the whole core system wasn't designed to do
that. In effect it could be said that HACS was 2 dimensional instead
of 3 dimensional system.

So this vertical dimension is where the 'fully tachymetric' US and
German systems are still ahead and it seems even the Italian and
Japanese ones as well.

It seems that it was 1944 or 1945 that some ships (one Ibelieve) with
HACS had the type 275 microwave track locking radar added to replace
the range only 285 50cm unit and this is what finally allowed a
complete solution.

Note the problem with HACS has nothing to do so far with the lack of
Remote Power Control for pointing of the guns directly or automatic
fuze setting machines. That's another problem area.

>
> Anyway so now it seems we have RN better guns but lacked
> the fire control for light guns, so I presume the better guns are
> the light stuff only.

The best british light weapon would have been the 40mm 2 pdr 'pom pom'
on a power driven quad or octouple mount. This weapon had a heavy
projectile but very low muzzle velocity of 650m/s that made it short
ranged and inaccurate at ranges neccesary to deter an attacker.
Remote power control didn't appear till mid 1943 and gyro sights till
1945 while higher muzzle velocity version with new amunition were also
introduced late war. Prior to this aiming appears to have been by the
estimated deflection being entered manually into the gunner sighting
system. The round lacked a tracer so it could not easily be aimed.

The standard US weapon was the 1.1 inch 28mm gun which had a high
muzzle velocity and came in quad mounts that were remote power driven
and aimed remotely by a 'dummy sight' ie a sight without any computing
capability or gyros. The gun had a good muzzle velocity of around
900m/s but fired a low rate (the quad mount was chosen to match the
0.5 calibre browning in cadence) and the projectile was considered a
little light.

In other words both the USN's and the RN's light AAA was considered to
have serious deficiencies.

>
> > The latter matters more I think.
>
> Good, then you would know the RN had fire control for their light
> AA pieces before the USN, since the idea of the multiple 2 pounder
> was to justify the cost of the control.

I question that widely made claim about the pom pom as I see little
evidence of particualry wide deployment or sophistication of the 2
pounder pom pom system. The sighting arrangments were quite crude.

It also somewhat irrelevant to the 'war'; the US Mk 51 fire control
system for the 40mm bofors, which incorporated the K14 gyro site was
in mass production and widely equipping ships before perl harbour and
the US entry into war. The Charles Stark Draper developed k14 gyro
sight on its own was used to equip 20mm canon and other small mounts
(eg the 1.1 inch gun) when supplies of compressed air (for gyro spin)
and electrical power made this possible. Gryo sights on their own are
really hard to use: you have to keep track of the range by a
stediometric range finder (enclosing the aircrafts known dialled in
wing span) while simultaneously tracking the recticle that moves
around to display the correct ofset. At least with the Mk51 the lead
angle was added in by the computer to the guns rather than the gunner
having to deflect the site with the complete gun.

I also doesn't seem that the pom pom gun in its quad mount and or its
fire control was all that effective or ahead of the US systems at the
beginning of the war. The US systems were RPC albeit with a dummy non
computing sight.

I would like to know what this advance fire control system that was in
service in 1940-1942 actually was.
http://en.wikipedia.org/wiki/QF_2_pounder_naval_gun
"An advanced weapon when introduced, by the outbreak of World War II
advances in aircraft had effectively made it obsolete. It was intended
that the curtain of fire it threw up would be sufficient to deter
attacking aircraft but lack of a suitable tracer round meant that the
barrage was unseen and so the deterrence factor was prevented from
being effective. It had a low velocity due to the relatively short
barrel and small charge, the fuse mechanism was unsatisfactory, the
weapons were extremely complex and prone to jamming, and the mountings
were enormously heavy and complicated and could not be produced
quickly enough or fitted widely enough. When HMS Prince of Wales was
attacked and sunk by Japanese aircraft near Singapore the subsequent
report judged that the single 40 mm Bofors gun, mounted on the
quarterdeck, had been a more effective anti-aircraft weapon than the
entire battery of multiple pom-pom mounts. Nevertheless, it was a
ubiquitous weapon that was never entirely displaced by the Bofors gun
during World War II. Later innovations such as remote power control
(RPC) coupled to an effective radar-equipped tachymetric (speed
predicting) director increased the accuracy enormously, and problems
with the fuses and reliability were also addressed. The single
mountings received a reprieve towards the end of the war, as the 20 mm
Oerlikon guns had insufficient stopping power to counter Japanese
Kamikaze aircraft and there were insufficient numbers of Bofors guns
to go round."
So the advanced light AA was unable to do much for HMS "Prince of
Wales" presumably because it wasn't advanced enough to make a
difference.

>
> > In both
> > cases the RN and USN gravitated towards the Bofors 40mm. It's true
> > that the RNs 2-pdr [4 cm/39 (1.575")] Mark VIII was superior to the
> > US 1.1 inch gun but the US moved rapidly and more thorougly to the
> > 40mm Bofors pointed by the Mk 51 FCS (fire control system) complete
> > with remote power control.
>
> So by the end of the war the US had the better light AA fire control,
> after being behind for the period 1939 to 1942, when the US began
> adopting the 40mm and associated fire control. With the USN always
> being ahead for heavy AA fire control.

I would say by the beginning of US involvement in the war in December
1942 its own light/medium AA was ahead of everyone's as well. Its
legacy 1.1 inch guns were maybe a bit weak but even they were upgraded
with gyro sights.

In the period 1939-42 it might be argued that the RN's medium AAA was
better but does that matter since although at that time the pom poms
were better but still inadequate for anything but a biplane torpedo
bomber itself. It's like saying a morris minor is ahead of a model T
ford for requirements of Indianapolis racing.

The 1.1 inch gun doesn't sound a soft touch either.

>
> The USN began fitting the mark 51 director in mid 1942 about
> 6 months after the first twin bofors mounts had been made.
>
> >> The RN was probably ahead of Germany, Italy and Japan
>
> > Nope the RN was well behind the German Navy which actually had quite
> > good systems available and also behind Japan and Italy. Not until the
> > introduction of radar did the gap begin to close.
>
> This is quite funny really.

I can hear you tittering. the fact however is that the HACS was well
behined the German systems at the start of the war.

>
> IJN the type 94 fire control has all the nice descriptions, tachymetric,
> triaxial director and a resolver for deck tilt, solutions could be given
> for non level flight from the computer in the transmitting station. The
> trouble was the computer took too long to come up with a solution.
> The system was modified to basically do some initial by eye shooting
> to at least provide some opposition.
>
> The poor performance at Midway meant some modifications had
> to be made, but no better system was developed during the war.

So, no doubt modifications eventually allowed faster calcuation of
target aircrafts velocity.

>
> And some IJN ships, including the Haruna had the older type 91,
> which was inferior to the type 94.

The advanced state of the Japanese navy and its size at the beginning
of the war and its failure to then maintain and keep pace with
developments is well known. There was a lot of old 'crap' in the RN
as well.

So the Type 94 had problems dealing with fast aircraft as did HACS, at
least it dealt with the full range of manovers. HACS continued to
require manual spoofing to cope with diving targets as well in this
case to overcome not a lack of computer speed but the lack of
provision of the basic mechanisms to begin with.

Presumably the Japanese attempted to address the 'speed issue'. The
challenge for the Japanese engineers and trades people was keeping
enough from being drafted.


>
> The above for the heavy AA, the IJN used the French Navy Le Prieur
> sights for light AA, along with the Ward Leonard remote power system
> for the triple 25mm guns. Production difficulties lead to the abandonment
> of the remote power option.
>
> And you should note the elevation of the IJN Dual purpose 5 inch guns
> was 55 degrees in most pre war destroyers.

Just over 40 degrees for the early RN systems, 80 or 85 degrees for
the better German systems, which weren't usually considered DP (except
on the Prinz Eugen where the 105MM flak was effectively DP) but
dedicated FLAK.

German destroyers tended to be larger than their British counterparts
and probably could afford to carry more FLAK.

>
> Italian AA had the same problem, as the Japanese, slow resolution of the
> data, and did not have gyrosights and so on for the light AA guns.
>
> >> in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
> >> the USN in 1945.
>
> > No, I'm not.
>
> You are the one who is talking light AA above, now we jump back
> to the heavy AA

My context was the expensive FCS for heavy AA, note I'm talking
about RN HACS vs USN Mk 37 and 5 inch DP and the equivalent German
systems.

>
> >the US 5 inch mounts and its associated tachymetric
> > fire control system has a history going back to 1932 when development
> > of the Sperry Mk 1 computer was begun as part of the Mk 37 fire
> > control system for the 5"/38 DP mount about the same time the RN was
> > developing the HACS.
>
> Like the fact the RN had HACS in service before 1932 you mean?

Ok, but the US contempoaries to the UK's HACS ; in other words the
'range keeping' precurors to the Mk 37 were already tachymetric,
though not able to deal with diving aircraft.

SNIP
>
> The mark 37, the ship borne gold standard of heavy AA for WWII
> did its tests in 1939. Those two extra years of peace made a big
> difference to the standards the USN could adopt in WWII, coupled
> with the combat reports it received.

Prior to the Mark 37 FCS with its Mk 1A computer the US already had
some tachometric FCS systems for heavy AAA so much of the
infrastructure such as AC power etc was already in place. Likewise
the infrastructure as measured by human knowledge base, specialist
engineers, technicians, craftsmen had been built up by the prior
efforts likewise for provision of the necccesary services such as AC
power as well as actually having room in the turrets for the necessary
equipement.

There is actually an intelligent and insightful question to ask: why
did the RN get stuck with HACS which is being obscured by your frantic
desire to prove my anti British but pro German (and pro American
bias.)

The reality is that the RN grossly underestimated what would be needed
to deal with modern aircraft and paid a price for it.

>
> > The RN almost certainly had the worst AAA systems of any of the
> > combatants at the start of the war: worse than US, German, Italian
> > and Japanese and never really solved all their its problems until 1945
> > since the existing systems were resistant to modification since they
> > had been designed on the incorrect premises.
>
> So the idea is the RN was inferior to the IJN and RM in both heavy
> and light AA systems for the entire war, or will we have more switching
> between heavy AA and light AA to suit the comparisons.

I switched to light AAA only in response to another poster. RN light
AAA is normally lauded.

>
> It will be interesting to see what the superior IJN and RM systems
> look like.

The Japanese had superior optics to any othe combatent. Specialist
machinary is an Italian Forte' I would not be suprised if they
produced a competent result in fire control.


>
> > The German navy was
> > second behind the US and certainly well ahead in regards to the
> > sophistication of its AAA systems on its larger ships though a few
> > errors such as using open mounts meant that the sophisticated control
> > gear was compromised by sea water ingress far to frequently.
>
> Take a look at how the German Naval 37mm gun worked at the
> start of the war, nothing like a single shot light AA weapon. This
> rather compromised the effort into making the better fire controls.
> They needed an upgrade from the 37mm AA gun developed
> for non ship use.

I have not problem with acknowleging the poor rate of fire of the
German 37mm gun.. The German naval single shot 37mm gun was the
German disaster as it was another factor that may have cost the
Bismark. A good powerfull round with good ballistics in a reliable
weapon that however had to be individually loaded and so could only
fire 30 rpm. It was on a gyro stabilised mount.

>
> And yes the German naval AA mountings and fire controls were
> overall better than the RN at the start of the war.

The core HACS "may" I emphasise "may" have improved ahead of the
German systems by the end of the war as the RN was able to integrate
radar with add on gyros to sort of automatically spoof the limted core
system to bypass one of its two shortcomings. If we include what
radar made possible then this is more certain to be true.

However German system were fully tachymetric to start with:- it should
have been relatively easy for them to inject the range data from their
Hohtenweil or late model Seetakt radars in lieu of the optical range
finder thus achieving the same effect as HACS (no GR or GRUB ie
Gyro's needed to be added as thety were already integrated.)
Photographs show FuMO 26 antena on the Prinz Eugen with a height
finding antena added to the directors radar.

I have no source of whether this is indeed what was done, but it is
highly plausible as the radar was warning of airborn threats and
providing range and bearing information.

>
> > I'm not trying to 'dump' on the British or RN but this is a case when
> > a group of people got it wrong.
>
> However "they got it wrong" will be repeated several times.

Yep, that's simply part of prosecuting an argument: you argue the
point from several perspectives to cover all bases. Its not a sign of
excess bias just thoroughness.

That is the point of this subthread and the consensus. There were no
doubt individuals within the RN raising alarm bells but they were
unable to push through their point and were simply ignored.

>
> I do note the usual praise of the Germans, including what the
> might/cloud have done, they were significantly ahead of the RN
> in fire control in 1939. I do note however that nothing is actually
> mentioned about the claimed superior Japanese and Italian systems.

At least two posters in this thread made the erroneous claim that the
RN was ahead of all of the axis in naval fire controls, the context
clearly being the sophisticated and expensive fire controls required
for effective heavy AAA. That is simply an in correct belief with a
wide body of writing pointing to the limitation assumptions and
therefore primitive nature of HACS and the legacy it left those trying
to make it work against modern ww2 aggressor aircraft.

It seems in your characteristically reflexive defence of a British
cock-up you would have me not argue my point to satisfy your
preferences.

My WW2 topic might be German electronics but it is not a bias in
argument but a bias in focus; specialisation. The problem with being
a 'pro' or 'anti' person is that it makes for poor understanding of
history.

>
> > First of all the German computer systems were fully tachymetric:
> > something which can't be said of the HACS in any way so the German
> > systems produced a far better firing solution and they did so
> > continuously.
>
> Yes.

OK, so we have that in agreement, for early war HACS at least.

>
> > Basically in the RN's HACS system an officer "the control officer"
> > had to estimate the targets speed and feed it manually into the
> > computer which then used the current position and the estimated speed
> > to calculate a firing solution inclusive of the considerable dead time
> > required to manually set the fuze and load the gun.
>
> Actually read the HACS reference provided, the bit about most
> larger ships used fuse setting machines?

There are two types of fuze setting machines: those that are manual in
which a human reads a gauge from the FCS and then manualy adjusts a
dial accordingly which then sets the fuze or those that are automatic
in which the fuze mechanism is set directly from the predictors
output.

I read that the fuze setting machines in the RN capital ships were
manual and separate from any power loading device.

The ideal placement of the fuze setting machine was as an integral
part of a power feeding system. I know of only 3 guns that achieved
this; the US 90mm, the German 128mm FLAK 40 and the latter versions
of UK 3.7 inch from the Mk 3a onwards.

The US twin 5"/38 incorporated automatic fuze setting into the
munitions hoist so that the rounds fuze could be set and power ramed
moments after release.

>
> > The HACS was
> > incapable of calculating the speed directly using information from the
> > director and optical range finders and apparently never gained this
> > ability though it eventually gained this via the use of additional
> > circuits added to radar when radar became available.
>
> So let me understand this it never gained it but it gained it?

It never gained the ability to calculate velocity by optical means
alone; that's actually clear from my sentence.

It sounds like what happened is that when the GRUBs were added they
calculated the velocity of the target using a hybrid optical-radar
system referenced to gyroscopes that compensated for turning of the
ship and then entered it where the control officer used to put his
manual estimate.

Now the HACS is getting accurate and timely velocity information from
the type 285 & GRUB in the horizontal plane and tracking it but it
was not set up to handle the vertical plane ie height changes.

AFAIKT the Germans mainly attacked ships with torpedo bombers or dive
bombers or slant bombers. Level bombers were only used with guided
weapons at least in the latter stages of the war.

>
> > It initially
> > also lacked the ability to engage diving and maneuvering targets.
> > Since the germans (ju 87 and ju 88) and Japanese were rather good at
> > dive bombing this was a serious problem.
>
> Actually the German dive bombers needed more practice to hit
> moving ships and it took a while to figure it out. Things like
> Gloucester and Fiji being sunk after they were out of main AA
> ammunition indicate things were a little different to that being
> claimed.

Between 21st May and 1st June 1941, during the battle and evacuation
of Crete, the Royal Navy suffered 3 Cruisers and 6 Destroyers sunk, 1
Carrier, 2 Battleships, 5 Cruisers and 5 Destroyers damaged, out of
the 1 Carrier, 4 Battleships, 10 Cruisers and 30 Destroyers deployed.

So the losses are altogether 11 out of 30 destroyers, 8 out 10
Cruisers, 2 out of 4 BBs, 1 out of 1 CA were neutrilized (sank or
damaged) in about a week by the LW... admitedly, with not much
opposition from the air.

And we are talking about a single Fliegerkorps, not 3 entire
Luftflotten, as during the Battle of Britian.

Fiji incidently was effectively sunk by a lone Me 109 which dove out
of clouds and delivered a direct hit.


>
> > It was designed to deal
> > with level bombers. When microwave radar became available the radars
> > circuits were finally able to provide this information automatically
> > but not via the optical systems.
>
> So the British jumped over optical and went straight to the
> first "modern" systems, that is radar controlled.

Not quite, they substituted radar range measurement for the lack
backup facilities for using stereoscopic range and rate measurment and
added gyroscopes and computers to establish the level speed of the
aircraft.
Optical sighting was still necessary. In the case of diving aircraft
individual aimed shots were no longer possible and barrage fire had to
be used. That lone Me 109 still stood a chance.

HACS was still not tachymetric and still had lmitations.

SNIP

>
> > You can read about HACS here:
>
> http://www.navweaps.com/index_tech/tech-066.htm
>
> It helps clear up the wrong claims being made.

What wrong claims?

Basically HACS was limited till 1945 irrespcetive of whether it had
the 285 50cm radar integrated or not. When the type 275 centric
radar replaced the 285 decometric set it seems to have been 1945 or
late 1944 in limited FKC form and essentially bypassed what was left
of HACS.

By this time the German Navy had ordered about 150 FuMO 231 track
locking radars to direct their guns, this was more or less a 50% scale
Manheim radar it had a 1.5m diameter dish and opperated at 27cm
intially, 3cm later. One was installed on a German destroyer that
never left the docks.


>
> > Secondly the German mounts, as far as larger ships are concerned,
> > were aimed by remote power control direct from the predictor at least
> > as far as elevation of the gun was concerned and the setting of the
> > fuze which was automatic and direct from the predictor via a fuze
> > setting mechanism adjacent to the gun breech. The round still had to
> > be manually transfered into the gun at which point continuously
> > running rollers pulled the round in.
>
> Hey the Germans had a fuse setting machine beside their gun, just like
> the RN ones. Though the RN ones look to be inferior.

Fuze setting machines need to be fast inoder to deal with close,
manouvering targets. The requirement is relaxed when dealing with
level bombers which is what the 88mm land based FLAK 37 could afford
to do; you know level bombers like B-17 and Lancasters were its
primary target.


>
> > In all of the RN's systems this was done manually until the second
> > half of the war when radar and electronics allowed a sort of partial
> > bypass of these problematic systems since circuits added to the radars
> > could give good position and rate information.
>
> Try again, the RN had remote power control, its weight and cost
> being a reason not to fit it to destroyers, as it would push up their
> size, complexity and cost.

Lack of RPC was however not the main issue, lack of tachyometry was.

>
> > In the RN's system
> > the fuze delay time was set by a man with a spanner or by a fuze
> > setting machine in which the delay was entered into the machine
> > manually after having been read from guages. RPC was only added
> > later to the RN's systems.
>
> Note the man with a spanner line, it will be repeated because it
> makes them sound so bad, you know like the Luftwaffe 88mm
> fuse setting arrangement as of pre war.

The reality remains that a man with a spanner set the fuzes on British
destroyers, unlike in the American system.

Remember this started out as a comparison between British and US ship
building efficiency.

Now, as you bringing up the pre war FLAK 18 (early 88mm.) : Fuze
setting machines need to be fast inoder to deal with close,
manouvering targets that ships face.

The German ground based FLAK guns performed a different job to that of
a naval gun; they could truely afford to be specialised in high
altitude level bombers becuase that's how Lancaster and B-17's
attacked. This is not the situation for ships AA defences on a
ship. Nor did they need a stable gyroscopic reference.

Having said that; the German gound based predictors did not have the
limitations of the HACS even if the 88 gun whether FLAK 18 or upgraded
FLAK 36 or FLAK 37 were manually trained.

>
> > You can see an explanation of one of the german systems here:
> >http://www.navweaps.com/Weapons/WNGER_41-65_skc33.htm
>
> Limited RPC.

This is what "Limited RPC" means. Automatic remote power control was
applied to
1 elevation of the gun, which would need to change rapidly in oder to
accomodate to fast approaching targets with the setting passed
directly from the FLAK director.
2 Automatic triaxial stabalisation of the gun directly from gyroscopes
and compass i.e stabalisation of elevation, cross leveling and taverse
were all remote power driven
3 fuze setting from predictor.

The traverse of the gun was power driven but NOT linked diretly to the
predictor but note that gyrostablisation was applied to the traverse.

RPC on the traverse did not contribut much as the other angles were
the more serious contraints. Gunners merely used the 'match the dial'
method but did not have to worry about ships movements or cranking and
handle.

The alternative to gyrostabalisation was to have a man peering at the
horizon through a sight whose job it was to either act as a gyroscope
by keeping fixed to the horrison or fire the guns at the peak or crest
of the waves.


>
> >http://www.navweaps.com/Weapons/WNGER_41-65_skc33_pics.htm
>
> The above is pictures

Yes, you can see the auto loaders and the fuze setting machines

>
> >http://dcoward.best.vwh.net/analog/ford.htm
>
> The Ford URL is a US system.
>
> >http://www.navweaps.com/index_tech/tech-013.htm
>
> This above URL rather puts a dampener on the wonder German
> electronics in the Prinz Eugen.

It does no such thing, anywhere.

It notes that the US had superior radar systems by the end of the war.

By the end of the war the German technology was catching up after its
neglect of the high frequency radar field.

Optivally in terms of sights, range finders, stabalized optics,
computing accuracy the German systems were first rate.

They had superior night vision optics and range finders and even had
passive infrared systems on their capital ships.

As I pointed out about 150 x FuMO 231 Euklid radar lock directors
had been ordered and delivery was starting. So it can be said that
both the Germans and British were behined the US untill 1945 when
the British started to catch up with the type 275 radar while the
Germans
were introducing the Euklid FuMO 231 running a few months behined the
British. An academic exercise due to the end of the war approaching.

The German Seetakt radar (13kW) however was behined the British 274
and 275 radar
(25kW and later 125kW) in transimission power which meant that the
British radar consistently picked
up the German opponent first even though both were limited by the
horizon.

The Germans company GEMA raised power to 125kW and 400kW but far to
late to
see service at sea, only on land.

>
> Yes the advertising for the Germans is in full swing, no Italians
> or Japanese make the cut though.

The Italians were out of action by 1943 so comparison isn't possible.
The Japanese I rather suspect improved their gear.

>
> The 1931 German AA fire control version required some 20 minutes
> to spin up the main gyros, they were so big it was a dockyard job to
> replace them, a counter to the advantage of them providing a good
> artificial horizon.

It's not a good counter.

The value of the FCS is that despite its weight it dramatically
improves the effectiveness of the ships armament by making its fire
accurate.

>
> The 1933 version came in at 40.4 tons, up from the 21 tons of
> the 1931 version, the big gyro rotors coming in at 260 Kg each.
> The director weight excludes the amplifiers and generators.
>
> The 1937 version, for Bismarck, Tirpitz and Prinz Eugen eliminated
> the big gyros but then needed 5 tons of ballast to maintain centre
> of gravity, overall weight was dropped to 36 tons. (All metric tons).
>
> A trouble with all the above designs was the gimbal rings forming
> the gun angle converter also carried the weight of the director, which
> was an obstacle to eliminating vibrations.

You appear to be refering to the main directors of capital ships.
The gunnery they produced
was accurate enough: Scharnhorst achieved the longest recodered hit at
26,000 yards using this
technology despite the possibility that the whole director had the
pickoffs mounted on the massive gimballs.

There was plently of respect for the German cruisers abilities to
achieve hits when their optical systems
could be used.

>
> When it came to AA radar fire control the navy adopted the Luftwaffe's
> Wurzburg system but this was too heavy for most ships. Tirpitz and
> some of the AA ships were given sets.

They presumably used optical aiming with radar ranging using the
Seetakt style FuMO 26 and FuMO 27; this didn't require a Wurzburg or
Manheim radar which were both full gunlaying radars and could track a
target in 3 dimensions and pass data directly to the predictor, the
Mannheim even having a track lock function.

>
> > German electrical engineers and scientists had perfected an amplifying
> > device called the 'magnetic amplifier' today refered to as a saturable
> > reactor. This rugged device made possible the Fi.103/B1, A4/V2 and
> > for the german navy remote power driven turrets free from the fear of
> > thermionic vacuum tube failure.
>
> Ah yes, we are pausing for the advertising break.

It's a matter of historical fact that the servo technology developed
in Germany was appreciated and used by the allies post war: untill the
development of transitors in the mid 1950s and early 1960s the
magnetic amplifier was the only solid state device around. It made
possible large gyro stabalised missiles and was used throughout the
USN post war and turned up in such things as the B-47 tail turret.

>
> > The systems of the Prinz Eugen
> > rather surprised the USN and untill the mid to late 1950s
> > revolutionized power electronics until the event of solid state power
> > electronics.
>
> Actually what the USN looked at closely was the passive sonar
> on board the cruiser, in particular things like wavelengths.

And the magnetic amplifiers.

>
> > Another unique aspect of the German systems was the
> > large number of computers/directors which allowed the ships to engage
> > a larger number of targets. Due to the restrictions of the Versailes
> > treaty and the fear of war with Poland in the 1930s the Germans saw
> > fire control as a manner of improving the odds.
>
> The Bismarck class carried 6 directors for 8 AA turrets, the
> Hippers 4 directors for 6 AA turrets.

Indicating a well founded fear of saturation attacks.

>
> The RN went with 4 directors for it main ships, 2 turrets per
> director, the USN battleships also went with 4 directors.
> Ark Royal and the Illustrious class actually had more main AA
> directors than the standard US carrier.
>
> > (The bismark had these systems but the front set of 4 turrets had been
> > upgraded to a faster traversing design while the rear had not, when
> > the Swordfish approached the Fire Control Systems did not take into
> > account the slower traversing units, thus the swordfish got through
> > the heavy FLAK at which point the inferior German medium 37mm let them
> > through)
>
> The idea the wild weather with its bad visibility had nothing to
> do with the situation is remarkable. Bismarck was actually sailing
> through a weather front when the second Swordfish strike tried
> to attack, the aircraft were split up, sections attacking individually,
> which should maximise AA effectiveness.
>
> There was no saturation of the defences.

There was a dispersal of the defences and the approach was from where
the guns
had not been properly set up to use the directors.

>
> > The lack of Duel Purpose (eg 5 inch guns) on German capital ships
> > which used sperate 6 inch (presumably to deal with the fear of on
> > rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
> > doctrinal problem of immaturity from lack of experience but a fear of
> > on rushing destroyers and saturation attacks that comes from expecting
> > to be the numerically inferior force.
>
> Or perhaps the same reason the RN went to the 5.25 inch gun for
> its battleship secondary armament, the need for a shell to make a big
> mess of any attacking destroyer meant 4 inch guns were simply too
> light.

The Germans went for 150mm guns in order to try and gain an advantage;
also because Polish destroyers had been exceding treaty calibres with
the use of 135mm or 140mm guns.

The Narvick class destroyers 6 inch 150mm guns had sufficient
elevation for them to be used in the FLAK role.

>
> The one criticism of the USN 5 inch 38 was "lightness", when
> dealing with ships, hence the idea of the USN 5 inch 51 calibre.
>
> And as for Bismarck there is simply the way it was an updated
> Baden class, with an AA suite added.

The myth, normally repeated with the claimed 'fact' that the German
battleships had their FCS above the armour belt has been dismissed by
examination of the wrekage of the Bismark.
See http://en.wikipedia.org/wiki/German_battleship_Bismarck, the ship
was far more than a 'Baden' class and its armour appears to have not
failed despite the lack of the 'all or nothing' armour concept.

>
> > Where the German navy fell behind was in high frequency radar or and
> > something called 'lobe switching' which German officers had been
> > offered in 1935 but had rejected.
>
> Somehow the Germans always seem to do it but never actually use it.

In this case they did and could have done it much earlier.

Lobe switching was demonstated in 1935 at GEMA and incorporated as a
retrofittable item to GEMA's Seetakt radars delivered to the Germany
Navy. It was incorporated into GEMA's Freya radars delivered to the
Luftwaffe as well as Lichtenstein radars. It was a stodgy procurment
decision only by the German Navy. Fritz Trenke, a German WW2 radar
expert, describes it being incorporated from 1940 so maybe the it was
only lower radar power that put the German ships at an disadvantage.

Doctrinally the German navy believed that radar would disclose the
position of a ship and should only be used for ranging in combat or as
a navigation aid. Night vision optics and passive infrared imaging
and ranging systems were thus developed and deployed. Of course
radar outperformed the optical systems at night and in bad weather.

The PPI version of Hohtenweil could also use lobe switching and
despite its 53cm wavelenght could still find a life raft or a
periscope.

> > However around 1942/43 Telefunken
> > engineers succeeded in a revolutionary improvements in powerful high
> > frequency disk triodes able to produced high power outputs (50kw) in
> > the 10-27cm range which while not in the league of the magnetron in
> > high frequency was enough to aim guns by with modest antenna the final
> > system allowed slaving of remotely power guns to the FuMO 231 Euklid
> > fire control system intended for the Z55 class of destroyers that had
> > very sophisticated AAA defenses.
>
> What we have here is the Germans are allowed what they are supposed
> to built past war as proof of german technology. The RN is restricted to
> only the wartime systems it used.

Early 1945 the RN introduces track locking AAA radar. Around the
same time the German start production of the same thing. A few months
lag in serive intorduction at most. It was 1943 before even a PPI
centrimentric set became available to the convoy escorts and british
warships.

The USN was clearly ahead. The RN not so much at all.



>
> In which case note the RN mark VI fire control, it just made WWII.
>
> The Z55 class were a paper project. It will be interesting to see how
> many of these revolutionary electronic devices made it into service.

They were being fitted out in the docks. They were not a paper
project. Euklid had been built, tested and production had started
and one seems to have been fitted.

The guns were proably similar to the FLAK 40 with power drawn in and
intergral fuze setting. At 5 inches/127mm and 45 calibres it was
proably more powerfull than the US 5"/38 and had a better fuze setting
mechanism.

You can see the round in the fuze setter here:
http://www.missing-lynx.com/library/german/flakarticle_dmouritzsen12.jpg
It shows a shell in the fuze setter ready to be flipped into the
ramming position.

Note the use of single piece amunition as oppsed to the seperate
propellent cartridge.

>
> The problem with radar fire control is the width of its beam, the
> smaller the wavelength the smaller the width, and so the lower the
> chance the radar is tracking a nearby aircraft, not the one the guns
> are trying to shoot at. Of course larger antenna arrays can reduce
> the beam width but that costs weight.

Indeed, though the problems of tracking and acquistion with a narrow
beam introduces new issues that were intially hard to solve.

>
> The 1944 USN mark 61 for the 40 mm projected the radar display
> onto the sight's field of view to help solve this problem.

I believe it entered service in 1944.

>
> It should be noted the light AA directors did not have to be as
> sophisticated as the main gun directors, the ranges were that
> much shorter, errors mattered less and speed of solution was
> important given the speed of the aircraft, so you could "cut
> corners".

Actually I think that 'cutting corners' was a result of the technolgy
to produce a miniturised fcs was just not there yet.

The B-29 had a better FCS then most naval guns.

>
> And of course it was things like proximity fuses that enabled
> the heavy AA guns a real chance against rapidly closing aircraft.

Even without proximity fuzes radar proper radar directed (M9 director
and SCR584) gun fire was quite effective. FuMO 231 would have also
produced a big increase in effectiveness.

Note during the Anzio landings in 1943 the Germans effectively jamed
the US armies SCR-284gun director radars with noise jamming and duppel
(window) and the SCR 584microwave radar had to be rushed.

>
> > Smaller German ships lacked the the remote power control however the
> > directors appear to have been fully tachimetric the problem with HACS
> > was the lack of support for full velocity calculation and the rougher
> > firing solution rather than the lack of remote power control for the
> > guns in most early British Navy heavy AAA.
>
> The German destroyers never mounted DP guns, pre war their
> AA was four 37mm pieces. The Germans then went to the
> 5.9 inch gun as the destroyer armament.

The 5.9 inch guns of the Narvik class had a resonable high elevation
capability, enough to be used a FLAK

>
> It was not until the never completed Z46 class that the new
> 5.1 inch gun in twin DP mounts was projected as the main
> armament, together with six improved 37 mm pieces and
> eight 20mm guns.

The intention was that EUKLID FuMO 231 director would be used and the
37mm pieces would have been replaced by the 5.5cm Garaet 58 'one hit
to kill' weapon while the 2.0cm pieces would be replaced by 30mm guns
based on the Luftwaffes Mk 103. A gun with much higher cadence, throw
weight and better ballistics than the quadvierling.

>
> Even the pre war torpedo boats, despite mounting the 4.1 inch
> gun, restricted maximum elevation to 50 degrees.
>
> > In my opinion the British Army was the Cinderella of the services:
> > its 3.7 inch QF gun showed that a good job could be gun when the
> > automatic fuze setter and power loader was added and latter remote
> > power control. The Royal Navies radars were also based on the UK
> > Armies AMES radars.
>
> This is interesting, what ever happened to the RAF systems. The RN
> and RAF were both experimenting with radar pre war.

The good stuff, pre microwave, came out of the Armies 50cm work AMES
radars this includes chain home low and the Type 284 and 285.

> Then the
> British hit a jackpot with the cavity magnetron.

Indeed, luckily for them someone recognised its value.

>
> > The RN simply seems to have gotten it wrong and then, having not
> > cultivated the skills and manufacturing industry to make the control
> > gear necessary found it difficult to improve its systems in the
> > quantities required.
>
> Of course this ignores the long development times involved in
> actually creating sophisticated fire controls, and the fact that
> not even the US had spare fire controls for the RN indicates
> the manufacturing effort.

It doesn't ignore the long development times involved. It does quite
the opposite.
The failure to plan a succesor for HACS early enough created many
problems.


>
> And of course the RN did improve the systems, more gyro controls
> and of course radar which provided a short cut, given the size and
> development time of any new mechanical computers. (Hint, the USN
> mark 37 computer was so big it needed to be below decks, and this
> made it hard to fit to older ships). The cavity magnetron meant
> smaller radars, less weight, and narrower beams, good for fire
> control.

The RN habbit of revamping old ships into new ones to circumvent naval
limitations treaties undoutably contributed to this.

>
> The lack of heavy AA in the RN destroyers can be seen by the
> decisions to mount twin 4 inch or single 4 inch AA guns on some
> destroyers, as well as the experimental 4.7 inch mounting. See
> the L, M, O and P classes. It was not until the S class the standard
> RN 4.7 inch destroyer armament had 55 degree elevation.
>