soc.history.war.world-war-ii

In article
<390dfe37-5d40-4725-a1b4-4f2d46ea117c@f47g2000hsd.googlegroups.com>,
eunometic@yahoo.com.au () wrote:

> 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.

Everybody except you in fact.

> 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.

Not in any written source I have seen though of course they were in
English and may have been prejudiced.

> The Germans having a good stabalised mount

Neither the Italian or German stabilised mounts seem to have been
weather proof.

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

Well that is what you are claiming. However considering results makes
for a different argument. At Crete most if not all of the ships sunk by
the Luftwaffe had actually run out of AA ammunition.

> I also argue that Modifications really improve HACS as much as you
> infer either, as I will explain.

Pardon, should that be do not?

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

Really, what makes you think that? The KM adopted the Army 37mm guns
and produced single Bofors based on a Norwegian model. By 1944 the 2cm
was only considered useful in quad mounts.

> 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.


So you are arguing that the fact that Radar measurements removed the
requirement for measuring speed by optical methods was a fault. It was
something the Germans never managed as far as I know.

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


I am sure you can come up with cases where that happened.

> and this is what finally allowed a
> complete solution.

So the RN solved the problem.

> This weapon had a heavy
> projectile but very low muzzle velocity of 650m/s

Where did you get this from? The 2pdr came in two velocities with the
original being 622m/s and the wartime model firing a lighter shell at
732 m/s.

> Remote power control didn't appear till mid 1943 and gyro sights till
> 1945

No. You are right about RP but the UK started the war with Gyro sights.

> The round lacked a tracer so it could not easily be aimed.

Wrong again.

> 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.

Now that was a good trick since the Bofors was first mounted aboard US
ships in June 1942

> An advanced weapon when introduced, by the outbreak of World War II
> advances in aircraft had effectively made it obsolete.

It was however kept in service throughout the war and I do not consider
Wikpedia a reliable source. True given the same number of barrels and
the same fire control the Bofors was more effective.

> I would say by the beginning of US involvement in the war in December
> 1942

You really meant to say that?

> The 1.1 inch gun doesn't sound a soft touch either.
The 1.1 is generally acknowledged as one of the bigger US mistakes on
the same lines as their torpedoes.

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

Well no, German destroyers were overarmed and had similar AA armament
to RN ships but heavier surface armament.

> 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 USN Mk37 had two more years of peace time development than any RN
system, the Germans never got a DP gun into service and their AA systems
were not that impressive in combat results.

Given time I may be able to come up with a complete list of RN combat
losses but from memory more were lost to surface action, mines and
submarines than to aircraft attack. Certainly if RN AA was as bad as you
make it out to be the Luftwaffe and the Italian air force have to have
been totally incompetent to have failed to sink the entire fleet.


The USN adopted the Bofors because Britain was using it for both the
army and the RN. The Bofors gyro sight used by the RN and the USN was
developed due to British army orders. Britain invented the gyro sight
initially for fighters. Light AA did not need range finders but relied
on rate of change of angular momentum which was why gyro sights were
used anyway.


Ken Young