Anti-Aircraft fire

[Compo]

Some might find this extract interesting in understanding how hard it was for aa to "crash" en planes.

COYLE, EDWARD R. "AMBULANCING ON THE FRENCH FRONT"

ANTI-AIRCRAFT BATTERIES

LOCATED all along the front are batteries, which consist principally of French cannon that we have heard so much about, known to the world as 75's. While this type is most frequently used, there are some aircraft batteries of larger caliber, known as the 105's. The reason that these two types of guns are used exclusively is due to their flexibility. They can be changed to different angles and elevations and be fired with the rapidity so necessary in following an aeroplane in flight.

Aircraft batteries are always located where protection is necessary from aviators in the rear of the lines, also in the event of the enemy aviator being able to get by the batteries up front.

The guns are mounted over a pit on a revolving platform that can complete a circle. Counterweights are attached to the gun for elevation so that it can be changed quickly from the horizontal to very near a 90-degree angle, the direction, of course, being obtained by the shifting of the revolving platform.

Some very novel contrivances have been developed for computing ranges, and each aircraft battery uses every available device that is likely to assist them in making flying uncomfortable for the Boches. Where there are two or more of these batteries they are connected up with each other by telephone, and, as an enemy flyer comes within range of their guns, the angles are phoned back and forth, and with this knowledge they can make the location untenable, even if they do not bring the flyer down. I have seen many an enemy flyer get into these pockets and rejoice at the moment he discovered the trap that there were some clouds close by into which he could dodge and get away with his skin intact.

These planes are, in most instances, observation planes, either to see what is transpiring behind the lines or to take photographs of enemy positions. The bombing planes work mostly under cover of darkness, which enables them to come down much closer to earth.

To meet this condition there is located at each aircraft battery a device known as an audiphone. It is a large box-shaped affair, made of sheet metal about thirty-six inches square. Inside are fastened four small cones., in appearance much like victrola horns. These are in turn connected with a vibrator similar to that in an ordinary telephone receiver. To this are attached two rubber tubes, identical with the instrument used by doctors called a stethoscope, for listening to the heart.

This equipment is fastened to a post, and can be turned in any direction. The box-shaped device, working on a common axle, can be elevated or lowered at will. When an aviator is in the air a lookout places the two hard rubber tubes to his ears and turns the equipment in the general direction of the supposed location.

He then elevates and lowers the box-shaped device until he arrives at a position where the clearest motor vibrations are received, the post being marked off in degrees, like the revolving gun-platform. The arrow on the audiphone points to the degree indicated on the post, and thus the direction is obtained and the gun trained at the same degree.

Then there is a second arrow with a scale corresponding to the one upon which the gun is elevated. When the clearest vibrations come in, the angle at which the box rests is indicated, and this in turn is copied by the gun. The distance is estimated by the strength of the vibrations coming in on the receiving instrument. The general location is phoned to the searchlight stations and the light is projected to afford the batteries observation in the event that the aviator changes the direction of his flight after the first shot is fired.

These projectors in many instances depend, of course, upon the locations where the greatest aerial activities take place, run up as high as four and a half feet in size, and with three or four searchlights playing into the heavens it is very easy to discern an aeroplane, unless it is flying very high.

The French 75's make a wonderful anti-aircraft gun that, with the remarkable perfection that gunners have attained, insures an enemy aeroplane quite a warm reception. But, at best, machines brought down by either side by anti-aircraft guns are very few, for no matter how good the marksmanship the aeroplane always has the advantage. He can take to higher levels quickly and the higher his elevation the greater his security.

When a shot is fired at him in a certain position he knows that it will be from eight to eighteen seconds before the projectile will reach his elevation. By merely changing his course in a fast machine, four or five seconds will take him three or four hundred feet away from the bursting shell. But the frequency of direct hits in lower altitudes does not warrant aviators taking chances. They'd better be on their way.

COYLE, EDWARD R. AMBULANCING ON THE FRENCH FRONT NEW YORK, Copyright, 1918, BRITTON PUBLISHING COMPANY, INC.

<http://WWW.ukans.edu/~libsite/wwi-www/Coyle/CoyleTC.htm>

[Borden Battery]

The 1st Canadian Motor Machine Gun Brigade provided routine AA protection for either Canadian Corps headquarters or important industrial targets - most often in 1917. On other occasions they were used for extra AA security when VIPs were inspecting troops.

The 1CMMGB used groups of Vickers machine guns attached to special mounts.

Most war diary accounts stated either no enemy activity or no machines brought down. There are a couple accounts of enemy machines being hit - in this case the planes usually landed behind enemy lines.

[CSMMo]

Here's another way it was done. A cannon was detailed to AA duty, they used shrapnel rounds, estimated altitude, direction and speed and fired. Didn't hit many, but sure to gain their attention! (Note the cannon, camoflagued, behind the officer commanding the gun.)

[Compo]

There is a contributed article in The Western Front by Dr David Payne which gives a lot of history on aa in ww1 incuding the fact that early on in the war the planes were so slow that they mounted standard British 3 pounder guns on tractors and tried to follow the planes!

http://www.westernfront.co.uk/thegreatwar/...ntiaircraft.htm