Remote controled weapons in WWII

(Peter Stickney) wrote in message ...
In article ,
Charles Gray writes:
Numerous bombers and heavy fighters, especially thowse that entered
service post 1943 have reference to remote controlled weapons.

Now, the remote control part should be fairly easy, but how were
they aimed? I'm assuming that you linked the gunners controls in such
a way thatthe gun always fired at the point where he was aiming,
making allowences for the location of the gun-- but how effective were
they? How hard was it to keep them in repair, as that sounds like a
fairly complex and advanced system for the 1940's.

There were quite a few implementation of remote-controlled weapons
during WW 2. The level of sophistication varied greatly - from fixed
light machine guns pointing directly behind some bombers that couldn't
cover that area with aimed gune - (HE 111, and, IIRC, the Martin
Maryland - it worked about as well as could be expected, which is to
say, not very well at all) - to the U.S. A-26 and B-29's computer
controlled systems that automatically computed lead, jump, drop, and
the effects of altitude and temperature on the gun's trajectory, and
could aim several gun turrets from a single sighting station. (Oh,
yeah, it corrected for parallax errors for having the turrets adn the
sights in different locations. A B-29 gunner only had to place the
pipper of his sight on the target, and adjust the stadiametric range
circle as he tracked. The Fire COntrol System did the rest.

Several more sophisticated German systems existed.

1 Cleverly positioned cheek babettes on the Me 410.
2 The Ju 388 has a remotely controlled tail turret that had a duel
view persicope with ventral and dorsal optics for a single gunner who
could scan above and below the aircraft. It was ofset to avoid the
tail. (It was similar system to that of the A26 I believe)
3 The Heinkel He 177 had a single remote dorsal turret.
4 A Piaggio P.108 4 engined bomber had barbettes on the nacells. (I
think only a dozen entered service but they gave sterling sevice to
the Lufwaffe who captured them)
5 The FA13 system on the, Arado 240 and Arado Ar 440. (It had a
system called the FA13 with a periscope)
(The Ar 240/440 was to have an electric system but was switched to a
hydraulic one becuase of reliablity. The gunners reported difficulty
in spotting the attacking aircraft in the ventral view in time during
testing. I do not know if this problem was ever solved by anyone with
episcopes and wide angle optics including on the A26 or latter Ju 388)

6 The Ju 288 (a few of which entered service) had tail, chin/vental
and dorsal barbettes.

Some of the German systems had computing abillity that extended beyond
mere elevation.

In a fast aircraft that can be only intercepted in a tail chase these
periscopes probably make sense.



Those that missed out on service:
7 The Australian CA-11 WOOMERA (alson known as Wackett bomber, was
designated the CAC-CA-4)
8 The Bell XB42 Mixmaster. (Guns beautifull streamlined between
airlerons and flaps)
9 B36

The B29 unlike the B36 was weird because the sighting stations and
guns were so far offset that the computers had to compensate.

The B36 doesn't even seem to have a tail gunner?


Remote control was also a feature of AAA (Anti-Aircraft Artillery).
All combatants used this to some degree, eslecially for Medium &
Heavy (40mm & up) guns. Targets were tracked by radar or optical
systems, which fed the target's motion and position data to a
Mechanical or Electromechanical Analog Computer, which resolved the
pointing solution and time of flight (Fuze setting) solution for the
guns. Less sophisticated systems, such as those used by the Germans,
used the computer to move a set of pointers on the gun mounts, and the
Pointer and Trainer operators turned handwheels to move the gun's
position to match the computer's commands. The U.S., and later the
Brits, with better technology (Feedback control systems, Variacs adn
Amplidynes) were able to control the pointing of the guns, and the
setting of the fuzes directly.

The Germans had computing and servo systems for their ships.
Considering the extreme state of manpower shortages I can not see that
the use of the fully automatic systems could be justified. The
precision servo systems for the tens of thousands of German FLAK
systems would be impossible to build and service.

AFAIK see a flak predictor on the basis of a fusion of inputs from
sound, stereoscopic range finders, radar produces a firing solution as
to where the target aircarft will be in say 15 seconds and provides
elevation, azimuth, fuse timing and firing time data.

A fully servo opperated system would shave of a few seconds since the
servo could position the gun faster than the point and crank
opperators (giving the aircrat less time to evade) and save some
manpower however they would also require extra skilled manpower to
manufacture and service.

By this time the Germans were using 13 year olds and retirees to
opperate the FLAK.

I think designing such systems and building a few was well within
Germanies technical know how. Manufacturing in quantity would have
been beyond them.

The FLAK predictor computers were afterall already providing
milliampmeter signals to the display guages on the guns. The
American guns used big 100lb or so caste iron variable resistors/
potentiometers that must have taken a long time to machine and then
calibrate to the precision required. Add in the backlash free
gearboxes, servo motors and amplifiers and you have a task beyond the
scope of Germanies resources to supply and maintain in quantity in
quick time at least.

With the introduction of the SCR-584
autotracking (You lock it on to a target, and it tracks it
automatically) radar, which fed the Ballistic Computer directly,
Remote Power Control to the guns, and Proximity Fuzes, Anti-aircraft
engagements were completely automated - The Gun Crew's job was to feed
shells into the breech as fast as they could, and act as a backup to
the remote systems.

The U.S. Navy had a similar level of sophistication. All guns on a
large ship were remotely controlled in train & elevation by the Fire
Control Systems, and the firing of the guns was controlled by the
computer. These computers automatically tracked the designated
targets, and controlled rangefinders and pointing systems, as well as
the guns. (The Spotting and Rangefinding crews, once the system was
tracking, input corrections, rather than raw position inputs)
With the introduction of microwave radars, which could spot
shell splashes as well as track targets, and allow gunfire corrections
to be made, they were capable of completely blind fire. THis was a
significant advantage that no other combatant had. (The Brits came
close, but the Germans and the Japanese were never able to build
systems that could accurately position something as large as a 90mm
gun, let alone a Battleship Turret).

Not quite completley correct. The early German systems would servo
azimuth to a computer. The complication of servoing elevation being
considered pointless and not worth the effort becuase of the ranging
systems used involved braketing the target in anycase.

"The Enlightenment" wrote in message ...

The tubes involved were special power amplifier tubes with heavy anode
cathode currents that must have been erosive. I do not believe they
had nearly 10,000 hours life. Amplifying DC was not possible because
directly unlike today when complimentary npn and pnp transistors are
available only valves were available and they had very particular
biasing requirements.

While I am not doubting your explanation of the turrets electronics, I
must wonder what the engineers were drinking back then. They obviously
did not talk much with the radar folks.

In many WW2 era radars (ship, ground, and air), vibrators are not
used. In fact, garden variety 6L6 tubes (of guitar amp fame, these
days) were a favorite, used to vary the field windings in some sort of
motor-generator (Amplidynes were used, even back to the pre-War Navy
CXAM days, but there were some other types).

This was a very good system - responsive, accurate, and able to swing
an antenna around that was much heavyier than the turrets on an
airplane. Why did the aircraft gun people not use this technology
until later?

During the Korean war the electromechanical computers of the B29 could
not compute for the closing rates of the MiG 15s. I don't see how
they would have coped with an Me 262 in that case.

This problem was also around in other tracking radar computers.

William Donzelli

"The Enlightenment" wrote in message ...

Its sounds crude but was quite accurate. A full serve system would
involved resistors for position sensing that were amplified in DC,
amplidynes which operated in AC to generate mathematical functions
such as sine, cos etc (amplidyne is a sort of rotary transformer in
which the overlap of the poles of the two secondary windings are
added/subtracted from each other. The area of he poles can be used to
generate voltages that are functions of shaft position.

By the way, I think you are confusing "Amplidyne" with "Synchro" and
"Selsyn". An Amplidyne is a special motor-generator that basically
acts like a magnetic amplifier - vary the fields a little and get a
larger change on the output. A Synchro (or Selsyn) is what you mean -
a rotary transformer that can transmit angular data electrically
(generally with three wires as multiphase AC). The things that can
generate the sine and cosine from an angular shaft position are called
"Synchro Resolvers".

William Donzelli