No other invention in WW2 is credited with more decisive results in improving weapon accuracy than the VT Fuze. Invented by the British in 1940 then collaborated on with the Americans, it is credited with improving the effectiveness of Anti-Aircraft fire in the Pacific Campaign by 50% giving US Navy Forces a marked edge when fighting off Attacks from Japanese Aircraft and later the Kamikaze Suicide Aircraft. During the Battle of the Bulge the accuracy of Artillery was said to have increased 7 fold when VT Fuzed ammunition was used. Many German units were decimated in the open if caught by these shells. One of the biggest contributions though was in defeating the V1 Flying Bombs heading for England in 1944. The Gun Batteries moved to the Channel coast to intercept them were all armed with VT Fuzed ammunition and they shot down a large number of V1's as they came within range.
Most Ammunition used Fuzes that were either Direct Contact, Timed or set to explode at a certain altitude. All 3 of these methods had their drawbacks. American Scientists wondered if a small radio transmitter could be made that would withstand the G-Forces of being fired from a weapon. After tests it was found that miniature vacuum tubes could be used to house a small transmitter & receiver, that could be placed in to a fuze on a shell. It was demonstrated that ammunition using the new proximity fuze was far more accurate than normal ammunition using the standard fuzes. Mass production was quickly authorised and they were sent out to armaments manufacturers to be fitted on to shells. Making a timely contribution to the war effort on all fronts.
The Radio Transmitter was like a small Radar. It emitted a pulse and if the pulse struck an object such as an Aircraft the returning pulse would be received as interference. Once the interference reached a certain frequency the shell would explode, hopefully destroying whatever was being attacked.
Mk 53 Proximity Fuze