The "Victory Bomber" was a design by Barnes Wallis for a bomber that could carry a single large "earthquake" bomb. Victory Bomber - Wikipedia His specification was for a 50 ton bomber that could fly at high level, 45,000 feet needed to give the bomb speed in the drop, at 320 mph for 4,000 miles. It would carry a single 10-ton bomb. Defensive armament was minimal; speed and height would be its chief defence with a single 4-gun turret in the tail position for any fighter aircraft that did attempt to reach it.
...higher altitude = less accuracy? per the article,also ...those types of ''machines''' take much, much time to design, engineer, etc---as we saw in the tank thread = a tank is much simpler but still took much time and many models to produce the initial product ....