Automatic Aiming Cannon Could Hit Invisible Aircraft (Feb, 1929)

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Automatic Aiming Cannon Could Hit Invisible Aircraft

New anti-aircraft gun aims itself by sounding device to guard America from air raiders.

PEOPLE who lived in London during the late World War will vividly recall the feeling of helplessness that possessed them when Germany bombed that city on several occasions.

They will tell you that the murderous cargoes of bombs were dropped from Zeppelins and Gothas which cruised the thin upper realms of the heavens with nothing more harmful than an occasional searchlight beam touching them. The anti-aircraft guns were powerless. Why? Any aviator familiar with anti-aircraft ordnance could tell you. He would laugh at the thought of an anti-aircraft gun actually scoring a direct hit. Planes brought down by shrapnel from the ground were planes that were just “in the way,” he would tell you. And he was right— about those old anti-aircraft guns. But he would be wrong about the new “Robot Gun,” and well might he change the tone of his argument, for the new weapon is well nigh invincible, according to authorities in the army. What happened to London can never happen to America, they say. Here is the reason. There will be guarding all of America’s strategic cities batteries of guns which automatically and instantaneously compute trajectory, wind density, elevation and speed at which the target is moving, and which can hit aircraft too far away for the eye to see! These guns function through the medium of a new device called a torque amplifier, which automatically “lays” the gun, a field parlance has it. From three points, which define plane in which the target is moving, ears gather the sibilant the sibilant sounds of a distant motor. Instantly, as to a human brain, nerves of wire and stimuli of electricity instruct the torque amplifier as to the location of the target. With the speed of Electra the gun is aimed and fired. Not an attendant is near. The gun functions until a hit kills the droning of the motors.

With the old anti-aircraft guns data required for laying the guns were telephoned from a central station to the men directing them. Numerous instruments had to be used in observing the planes and computing the firing data. So many men were required to receive all the information and set the scales that not merely one but many errors resulted.

Then, after all was done the low velocity of the shells and the speed of the planes caused the projectile usually to be late in arriving where the plane had been, if it got that far. Little improvement was made over that system for some years after the war.

Today through the use of the equipment devised by the late Major W. P. Wilson of the Ordnance Bureau, the electrically controlled robot guns, which are three-inch pieces, are being proved through tests conducted at Aberdeen Proving Grounds, Maryland.

Army officers regard the new guns as almost human, in the same way people speak of the linotype and the adding machine; even more than human, because they minimize the effect of errors by the personnel.

It is predicted that a new day has dawned in the use of anti-aircraft ordnance, and that America will be immune from any attack by airplanes, formidable as the winged explosive carriers may be!

  1. Rick says: July 27, 200910:29 am

    If, as the article states, that’s supposed to be a three inch gun, then according to scale the one that is pictured is only about 20 inches long. And I love the way the author(s) state how invulnerable we’d be with these around our coasts!


  2. Thundercat says: July 27, 20091:01 pm

    Thank God! Finally, something to save me from the horrors of blimp attacks!

  3. JMyint says: July 27, 20093:06 pm

    I was curious. I knew the article was talking about predictors, the electromechanical computers used to aim AA artillery, but I guess he just didn’t come out and say it. Well I looked for Major W.P. Wilson and found that he was an inventor and engineer but not in the Ordinance Department but the Coastal Artillery Corps. The earliest mention of him I could find was a foot-note in the “Journal of the Franklin Institute”, July-December 1922, thanking him for the calculations require for the building of a Oscillograph Camera for the National Bureau of Standards. However and article in “The Coast Artillery Journal”, May 1923 states that Maj. Wilson submitted a sound plan for for an automatic ploting device and computing machine for anti-aircraft batteries that was similar to a device proposed by Maj. R.G. Groetzenburger of the Ordinance Department.

  4. Firebrand38 says: July 27, 20093:07 pm

    Not blimps. They couldn’t carry enough payload to make it worthwhile. Zeppelins on the other hand had participating in bombing raids over London during WW I and the first non-stop aircraft flight between European and American mainlands was the German ZR-3 (later the USS Los Angeles) which was a zeppelin being delivered to the US Navy in October 1924 as part of the war reparations.

    But this is irrelevant. The first non-stop transatlantic flight had taken place in June 1919 when Alcock and Brown flew a modified bomber between Newfoundland and Ireland in 72 hours.

    More to the point though, the first flat top aircraft carrier was converted in September of 1918. Prior to that the Japanese seaplane carrier Wakamiya conducted the world’s first naval-launched air raids on 5 September 1914 during the Siege of Tsingtao.

    So yeah Thundercat, you could say that they had their concerns (but not about blimps).

  5. Firebrand38 says: July 27, 20093:37 pm

    In the August 1928 Coast Artillery Journal we find “A new development this year in the direction of increased accuracy is the device known as the torque amplifier, by the use of which
    the battery is operated automatically from a distant station. The torque amplifiers are driven hy small electric motors and keep the gun set continuously at the proper elevation and azimuth. The importance of this development is in reducing the chance of personnel error. The pattern of the bursts is noticeably more uniform than the pattern made when firing with the follow-the-pointer system, and this is a better pattern than when sights are used.”

    Looking at the Feb 1929 Coast Artillery Journal page 107 we find “Another development is the torque amplifier which permits the guns to be laid by the data computer without the aid of
    traversing and elevating details at the guns. The type of sound locator now used is still the exponential horn, but corrections for sound lag and other conditions may now be applied automatically as is the case in gun fire. Furthermore, the data from the horns are received
    at an instrument known as a comparator. Here the operator matches his pointer with the one actuated by the horn and so moves the light. This permits of’ distant operation of the searchlight, thus keeping the operator from being blinded by his own beam. Sound locators are to be carried in specially designed vehicles so that the whole unit, lights and locators, would be able to make from 30 to 35 miles an hour on good roads.”

    Not quite the Robot Gun

  6. Eamonn says: July 27, 20097:00 pm

    Good thing they worked just as advertised, otherwise London might have been bombed by the Nazis. Let the Hun tremble before the might of our invincible robot guns!

  7. Stephen says: July 28, 20098:35 am

    Late in the Second World War a system like this was used as a defence against the German cruise missiles (the V-1). However, that automated gun was aimed by radar, not by sound tracking, which was of course far more reliable. They eventually got it up to an 82% success rate: see… .

  8. GrumpyKiwi says: July 29, 200910:08 pm

    Three inch is the calibre (or diameter of the barrel) of the weapon, not it’s size. (76mm). From the image supplied, I doubt it would fire at a high velocity, which is an important component of any AA weapon. And I would assume they would want the sound detectors to be seperated by a much larger margin.

  9. Firebrand38 says: July 29, 200910:23 pm

    The drawing was a case of artistic license coupled with ignorance.

    The 3 inch gun looked like this http://www.antiaircraft…

  10. Toronto says: July 29, 200911:54 pm

    I spent part of the 1970s living underneath a 3″/70 twin (it looked like this one:…)

    It wasn’t the most pleasant place to be while it was firing at 90 rounds per minute. (Not that you’d be lounging in your bunk at those times.)

  11. Jari says: August 2, 20096:29 pm

    As I served my national duty in AA corps as an radar engineer in eighties, this was a fashinating article. But microphones… As sounds are affected by wind and humidity, I’ll have my doubts about it’s accuracy even against zeppelins. Radar, of course is another thing. I’ll remember having fun with a Russian electromecanical servos, adders, substracters and other doodads, which comprised AA battery’s firing controller computer 🙂

  12. Firebrand38 says: August 2, 20097:43 pm

    Once again, in 1929 it’s all they had. After radar came into wide usage sound ranging against enemy artillery and aircraft went the way of the Dodo

    Back in 1917 it was in it’s infancy as this 1917 manual reveals http://cgsc.leavenworth…


    As to correcting for environment they really weren’t as stupid as all that as can be seen in this WW2 AA manual http://cgsc.leavenworth… where they tell how to make corrections based things like temp and humidity.

  13. jayessell says: August 2, 20098:16 pm

    When I think of ‘War Tubas’ I think of this……

    Especially at 05:30 or so.

  14. Jari says: August 3, 20096:23 pm

    Firebrand, thanks for the links to those documents, interesting reading. I have had Museum of Retro Technology on my bookmarks for a couple of years, though. Excellent site, btw. A bit of mindboggling, what kind of calculations can be done with pantographs, rollers and gearing.

  15. Firebrand38 says: August 3, 20097:05 pm

    Nice of you to say so. I try to make my self useful so Charlie will let me hang out.

    I know what you mean about calculations. My favorite example is back in the 50’s when Lockheed engineers designed the A-12 using slide rules.

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