ROBOT BOMBERS

Dominion, Volume 37, Issue 225, 20 June 1944, Page 4

ROBOT BOMBERS

Ail Artillery Concept PROBABLE ANTIDOTES All the known facts indicate that the German robot planes must be classified as artillery rather than bombers. Once it has been aimed at a target and fired the robot continues along a set course. It is not radio controlled. It thus comes closer to the role of a flying bullet than of an aeroplane laden with bombs. It is, in fact, a long-range projectile. These robot projectiles must be considered as an extension of Big Bertha, which startled Parisians in Great War I. Big Bertha had a range of 75 miles. It fired a projectile which weighed 2651 b. (high explosive charge about one-third of this), with a muzzle velocity of 5060 feet a second, or roughly 3000 miles an hour. The projectile rose over 100,000 feet into the air and subsequently descended on Paris. Altogether. 367 projectiles hit Paris and killed 256 persons. The time of flight was eight or nine minutes.

Rocket-propelled projectiles have since been used largely for anti-aircraft work. They differ from the gun principle in that they carry their own propellant, which continues to act for part or all of the time of flight. The recent pilotless aeroplanes or robot craft are an extension of the rocket projectile. Wings and equipment have been added to a projectile which is jet-propelled. One may well consider the merits of these robot aircraft from the facts so far discovered. Their range is said to be 150 miles maximum. Their speed compares with that of fighter aircraft. It is probably less, and a round figure of 200 miles an hour should be near enough. At maximum range these robot projectiles have a time of flight of 45 minutes. They are thus able to transport 23001 b. of high explosive 150 miles in 45 minutes as compared with roughly 5001 b. of high explosive carried 22 miles in threw minutes in a naval shell.

The speed of the robots is very low, and their range very great for a projectile. For the whole of the 45 minutes the robot is at the mercy of wind and weather as is a shell. The main difference is that the robot has automatic control. This length of flight necessarily introduces all manner of uncontrollable factors which must make accuracy negligible. A naval shell is designed to hit a target 100 yards long by some 20 yards wide at distances up to 22 miles. Actually at shorter ranges it is possible to hit a tennis court with great consistency This accuracy is possible by very careful allowance for all possible factors — temperature, barometer, curvature of the world, spin of the world, weight of projectile. and -wind. Big Bertha was capable of hitting a target two miles long and one mile wide fairly accurately at 75 miles. Errors which will creep into the robot projectile for wind alone are capable of deflecting it from its true target by distances amounting to 20 miles. Thus it could not guarantee to hit a target much smaller than 400 square miles. This corresponds to targets in Britain such as Greater London, the Isle of Wight, or certain military areas. , Even so, many of the robots would miss the target, probably half of them. Clearly these robot aeroplanes have a high nuisance but a low effective value. A ton of explosive which is liable to drop anywhere in southern England between London and, say, Bristol, must continue to have a nuisance value despite its inaccuracy. There is every reason to assume that an antidote will be found. In the case of big Bertha the antidote was to bomb the battery position. This can also be done to neutralize the robots. Though it is claimed that Allied fighters will blow themselves up in the resultant explosion if they attempt to shoof. down ■■robots, this has yet to be put to the test Special long-range armament may be required and it is thus probable that special robot destroyers will be evolved. The fact that evasive action cannot be taken by the robots increases the chances of hitting them. They would appear to fulfil every requirement for which anti-air-craft gunners pray—constant height, straight course, steady speed and lowish altitude. Robot shooting should develop into a specialized technique with effective results. All these problems would be greatly assisted if a robot were captured “alive.” Subsequent investigation would then appear to be a task for the “boys of the small back-rooms.”—E.A.A.