Chapter 827 Dam

"It seems that we have to restart the production of 150MM anti-aircraft guns."

Commander Arnold sighed in great depression. With the service of the XP-67 high-altitude fighter, the production of 150MM anti-aircraft guns was shelved. Because the cost of a 150mm anti-aircraft gun is almost as high as that of 5 XP-67 fighters, most people think that XP-67 fighters are enough to keep German bombers out, and there is no need to produce such expensive, time-consuming and labor-intensive anti-aircraft guns. Therefore, the anti-aircraft guns produced in the early stage were only deployed around Washington. Now the XP-67 high-altitude fighter group has been wiped out, and there is no defense force in the northeastern industrial zone that can threaten the German high-altitude bombers.

At this time, another news came that the attack aircraft taking off from the German aircraft carrier was bombing the Edwards Dam on the Kennebec River in Maine. This dam was built in 1837 and takes into account both power generation and navigation.

"Dam?" Before everyone could react, news came one after another that German attack aircraft were attacking dams in various parts of the northeastern industrial zone.

The United States is the second country in the world with the most dams. According to statistics from the U.S. Army Corps of Engineers, there are about 90,000 dams in the United States, not including those hydropower projects that are too small to be included in the statistical list.

The 20th century was the golden age of dam construction in the United States. Theodore Roosevelt, then President of the United States, wrote in 1908: "We should make the best use of the water power of every river." In the following decades, the U.S. dam-building boom swept almost all major rivers in the United States.

The dam-building boom during this period gave birth to the two most important hydropower stations in the United States: the Hoover Dam on the Colorado River, completed in 1936, and the Grand Coulee Dam on the Columbia River, completed in 1942. Until later generations, these two dams remained the most important forces for hydroelectric power generation in the United States.

President Wilkie asked hurriedly. "Have air defense forces been deployed around those dams?" Once these dams are destroyed, the power supply in the Northeast Industrial Zone will be greatly affected. Even if the carbon fiber filaments dropped by the German army are cleaned up, it is impossible to resume normal production.

Deploy air defense forces around thousands of dams? How is it possible.

"No, Mr. President, but we have deployed anti-mine nets upstream of some medium and large dams."

Medium and large dams are tall and strong. If bombs are dropped from the top, let alone whether the bombs dropped by high-altitude bombers can accurately hit the dam, even if they hit, it is difficult to create a huge gap to destroy it. If you want to cause fatal damage to the dam, you can only attack from the root of the dam, and torpedoes are naturally the best choice. Dropping torpedoes from the upstream direction can also increase the destructive power by using the water pressure of the explosion. If multiple torpedoes are concentrated to attack one point, it can cause huge damage to the dam.

"Then you can rest assured?" President Wilkie had not had time to breathe a sigh of relief when he saw Arnold's face suddenly change. "Commander Arnold? Any questions?"

"Mr. President, I mentioned to you last time that our air force has invented a new ricochet attack tactic." In this attack method, the B-25 needs to fly over the water at a very low altitude and high speed to approach the enemy ship. When it is close to the appropriate distance, it will drop a bomb (usually a 227 kg bomb). The bomb will fall on the water like a skipping stone, bounce up, fall down and bounce up again, until it hits the side of the ship and explodes.

President Wilkie nodded. "Yes, but our bombers can't get close to the German fleet at all, right?" They were wiped out by the German carrier-based aircraft outside the fleet, and no matter how good the tactics were, they were useless.

Arnold's face turned pale. "This new ricochet can also attack buildings such as dams. If the Germans also mastered this technology..." He felt that with the Germans' intelligence capabilities, they might have known the principle of this bomb long ago.

He guessed correctly that the Germans certainly mastered it. In the original World War II, the British used this ricochet to attack the German dam.

In January 1943, the British High Command launched the famous Ruhr Campaign and ordered the British Royal Air Force to focus on attacking Germany's Ruhr Industrial Zone from the air. The primary goal was to blow up three reservoir dams near the Ruhr.

The Ruhr Industrial Zone includes major cities such as Essen, Düsseldorf, and Dortmund. It is centered on heavy industries such as coal mining, steel, chemicals, and machinery manufacturing. Its industrial output value once accounted for 40% of the country, and it played a pivotal role in the German economy. The famous Krupp Steel Company in World War II was located in Essen, Ruhr Industrial Zone. During World War II, Krupp Steel Empire directly or indirectly employed 200,000 people, manufacturing cannons, armored vehicles, tanks, submarines and various light weapons for the German army, providing Germany with powerful military equipment for launching the war. It is no exaggeration to say that the Ruhr Industrial Zone was Germany's military supply base throughout World War II and the material basis for Germany to launch the world war.

The Germans naturally knew that these reservoir dams were the "weak ribs" of the industrial zone, and deployed heavy troops around the dams. Under the powerful anti-aircraft firepower, it was difficult for Allied aircraft to fly at low altitudes. However, the accuracy of dropping bombs at high altitudes was very limited. How to bomb the dams had become a difficult problem for the Allies.

British aviation engineer Barnes Wallis came up with a genius idea of ​​a super low-altitude bombing method. The bomber flew below 30 meters to avoid radar detection, and then dropped the bomb at an altitude of 18 meters, about 700 meters away from the dam, at a speed of 100 km/h. According to his calculations, the bomb would bounce 6 or 7 times to reach the dam like a skipping stone on the water, and finally hit the dam at a terminal speed of less than 5 m/s, and then fall into the water. After reaching a certain depth, it was detonated by a hydrostatic pressure fuse. Underwater explosions can cause pitting of the dam body, cavitation shearing, collapse and stretching, bending, and shock wave damage, which can effectively destroy the dam.

For this purpose, he also designed a special aerial bomb. This bomb is shaped like a barrel. When this bomb is dropped from a low altitude, it can rotate at a speed of 500 rpm, while jumping on the water surface and avoiding the mine protection net.

The Allies used this bomb and tactics, and after many serial bombings, the two dams in the Ruhr industrial area were destroyed. 400 million tons of flood water poured out, not only ravaging the surrounding arsenals and industrial parks, but also the people downstream suffered. It is reported that at least 30,000 people died in the flood disaster caused by the bombing.

The German attack aircraft that were attacking dams in various places were carrying this kind of ricochet bombs. Because there was no anti-aircraft firepower nearby, A-1 attack aircraft flew at a very low altitude close to the river surface and threw the ricochet bombs under the belly into the river. Then these ricochet bombs jumped on the water and rushed to the dam in the distance.