How did the Brits do it?

nt (Krztalizer) writes:

They built "Rotterdam" / H2S duplicates as well.

H2S was forbidden over land for quite a while. It was vital to the
Uboat campaign and the boffins figured that if used over Germany,
one *would* be captured and the secret blown. [There was no way to
destroy the magnatron w/o taking out the aircraft as well....]

They were right.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

rnf2 writes:


One way used was radio direction finding nad measuing the angles on
the source of german propraganda broadcasts...

DF on known emitters is an old ploy. You can tell where YOU are, or
where IT is. That was why Eisenhower's SHAEF transmitter was in the
area of Patton's First US Army Group.

There was also one German navaid that was not jammed but spoofed; a
receiver at one end of England listened to the modulated German
transmitter. The audio went across Britain to where a transmitter
on the same frequency rebroadcast it. Since the UK transmitter
was closer to the bomber.......

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

David Lesher wrote:

nt (Krztalizer) writes:

They built "Rotterdam" / H2S duplicates as well.

H2S was forbidden over land for quite a while. It was vital to the
Uboat campaign and the boffins figured that if used over Germany,
one *would* be captured and the secret blown. [There was no way to
destroy the magnatron w/o taking out the aircraft as well....]

That argument was made by the RN/Coastal Command, but Bomber Command
won the decision (by Churchill), and H2S went into service over land
right away. And a more or less intact magnetron was captured on one of
the very first missions, from a Stirling shot down near/over Rotterdam
(whence its German code name, Rotterdam Gerate) on 2 February 1943.

Guy

"David Lesher" wrote in message
...
rnf2 writes:

There was also one German navaid that was not jammed but spoofed; a
receiver at one end of England listened to the modulated German
transmitter. The audio went across Britain to where a transmitter
on the same frequency rebroadcast it. Since the UK transmitter
was closer to the bomber.......

Operation "Domino"
This was Y-Gerat (Y-Device) or Wotan II. The transmitter used was the
old 1930's Baird TV
transmitter at Alexandra Palace. It was a very effective
countermeasure. Wotan was the Norse god
with only one eye (one beam). It was also known as 'Benito'.
Basically the Y-Gerat worked by transmitting a single beam with Lorenz
characteristics, morse dots
received if you were on one side of the beam, dashes on the other and an
equisignal of continuous tone
if you were in the centre of the beam and on course. The bomb release
point was done by means of a
kind of remote Distance Measuring Equipment, in that a signal was sent
to a transponder in the aircraft and
a response returned, by measuring the delay between transmission of the
interrogation pulse and reception
of the response it was possible to calculate the distance fairly
accurately. A signal was sent to the aircraft to
release the bombs at the correct point allowing for altitude, speed and
distance to target etc.
The countermeasure involved intercepting the aircraft transponder signal
and retransmitting it through the
TV transmitter, which caused a false distance reading.

The earlier Knickebein (crooked leg) 2 beam system and the multi beam
X-gerat (X-device) had already
been countered. The loss of these was actually quite a blow, as the
later Y-Gerat was only capable
of handling one aircraft at a time, whereas Knickebein was in every
bomber. The Germans created a "Pathfinder"
force of their own, KG100, to use it.
Knickebein worked on the normal Lorenz frequencies around 30mhz and the
first jammers (code name 'Aspirin'
to counter the beams which were code named 'Headache') were actually
medical diathermy units which produced
powerful broadband noise.


The CO

David Lesher wrote in message ...

nt (Krztalizer) writes:

They built "Rotterdam" / H2S duplicates as well.

H2S was forbidden over land for quite a while. It was vital to the
Uboat campaign and the boffins figured that if used over Germany,
one *would* be captured and the secret blown. [There was no way to
destroy the magnatron w/o taking out the aircraft as well....]

They were right.


If it was that vital they would not have used it. The people who
'defined' vital were trying to bomb Germany. Oddly enough it was
Bomber Harris who appreciated that bombing U-Boat yards and basses was
a complete waste of effort.

The Germans were scammed into thinking their Metox boxes were leaking
radiation which were being used to track them. It was a technical
possibility and so they bought into it. That delayed the development
of a H2S detector (Naxos).

Ganton Pretz wrote:

If it was that vital they would not have used it. The people who
'defined' vital were trying to bomb Germany. Oddly enough it was
Bomber Harris who appreciated that bombing U-Boat yards and basses was
a complete waste of effort.

The Germans were scammed into thinking their Metox boxes were leaking
radiation which were being used to track them. It was a technical
possibility and so they bought into it. That delayed the development
of a H2S detector (Naxos).

What did "H2S" stand for, anyway. (Sounds like dihydrogen sulphide to
me.) Sorry if it has already been posted, I missed that part of the
thread.
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO
(If you're going to e-mail me, you'll have to get "yourfinger." out.)

"Andrew Chaplin" wrote in message
...
Ganton Pretz wrote:

If it was that vital they would not have used it. The people who
'defined' vital were trying to bomb Germany. Oddly enough it was
Bomber Harris who appreciated that bombing U-Boat yards and basses was
a complete waste of effort.

The Germans were scammed into thinking their Metox boxes were leaking
radiation which were being used to track them. It was a technical
possibility and so they bought into it. That delayed the development
of a H2S detector (Naxos).

What did "H2S" stand for, anyway. (Sounds like dihydrogen sulphide to
me.) Sorry if it has already been posted, I missed that part of the
thread.

There are at least versions of the story about the naming of the radar

1) Its original name was "Home Sweet Home" which was shortened
to H2S

2) Its original name was TF (for Town Finder) but a different
code name was required and an RAF type suggested
'H2S because it stinks'


Keith

"Keith Willshaw" wrote in message ...
"ArtKramr" wrote in message
...
Subject: How did the Brits do it?
From: "Keith Willshaw"
Date: 3/10/04 6:44 AM Pacific Standard Time
Message-id:


"ArtKramr" wrote in message
...
I think back to the war and the RAF heavies on their night missions.
Missions
flown in the winter usually were in atrocioius weather where there was
no
view
of the gound and the sky above was overcast. There was no way to shoot
at
star
fix or take a dirft reading from the ground. Working dead reckoning
from
England deep into Germany and any change in wind dorection or velocity
that
went undetected made dead reckoning navigation a hit and miss
proposition.
Often it was not just miss, it was gross miss. Knowing all this how
could
the
RAF ever hope to pull off these winter night missions successfully?
What
was
the logic that made them keep flying under these hopeless navigation
conditions? Anyone know?


This is a complex subject and a matter of some controversy
but unusually these days is on topic so I'll give it a go.

The RAF began the war in 1939 with a plan that envisaged
daylight precision bombing of military targets only. Unfortunately
catastrophic losses on early raids, 50% and higher, proved this
to be impossible. It was quite impossible politically and from
a morale point of view to simply stop bombing the Germans
This was especially true after the Blitz.

An attempt was made to use the techniques you describe
to bomb at night and the results as you would expect were
very mixed. In 1940 raids were mainly aimed at the invasion
barges in French and Belgian Ports and these being relatively
easy to locate at night results were acceptable.

However as targets deep in Germany were attacked it was evident
that the expected results were not being delivered.

An official report commissioned by the war office from the
economist David Miles Bensusan-Butt revealed that bombing
was shockingly inaccurate. Churchill recognised the importance
of the report - "this is a very serious paper and seems to
require urgent attention" and temporarily suspended bombing while
a solution was sought. This was to consist of four parts

1) The adoption of better navigational aids
2) Better crew training
3) Larger better equipped 4 engined bombers
4) A switch of tactics

Essentially the RAF decided that if they couldnt hit precision targets
then they would switch to targetting things they couldnt miss,
this was area bombing. The idea being that if you couldnt
hit the arms factory in the city you'd settle for flattening the
entire metropolis.

As the war progressed navigational aids like Gee and Oboe along
with Radar aids like H2S and the use of Pathfinders did improve
accuracy a great deal so that by 1944 the RAF were able to
atatck and obliterate targets varying from troop concentrations
in Normandy to entire cities.

Keith


Of course Gee Box and Oboe came very late in the war. I flew a number of
Gee
missions as the war drew to a close. But how anyone can do long range
dead
reckoning when wind drift and velocity cannot be reliably determined, with
no
view of the stars or gound, makes things a bit hopeless. But I would say
that
90% or more of those missions were flown without any electronic or radar
aids
at all.

Not really Art

Bomber command flew its first mission using Gee in late 1941.

On March 3 1942 the first major raid that utilised gee equipped
aircraft dropping flares for the main force was made against the
Renault works at Billancourt in France. 223 of 235 aircraft
found their target). Losses were very light (one Wellington was lost)
, and damage was evaluated as 'heavy'


I don't really think they put that factory out of action. As you say
they needed to physically illuminate the target.



By mid summer 1942 almost all BC aircraft had Gee. H2S began
arriving in service in 1943.


Knowing where one actually is and bombing accurately are related
issues but strictly speaking quite different.

GEE put a bomber in the general place it wanted to bomb and most of
the bombs might just do a bit of damage to something in the same town.