Chapter 488 Oscar-Class Nuclear Submarine
Machine tools are the mother machines of industry. All kinds of mechanical manufacturing are inseparable from machine tools. To put it in the words of that time, using machines to manufacture machines marked the arrival of the industrial age.
It is precisely because of the emergence of machine tools that high-precision processing of various parts has become possible. The cutting and processing of various parts can be achieved through the movement of the turning tool.
For example, to make a screw, you can fix the iron block on the machine tool, use a motor to drive it to rotate, and use a turning tool to cut on the side, and then you can process it. To make complex machinery, you need to cut a plane first, then turn it around, fix another axis, continue to rotate, and process another surface. Doing so will cause a certain error, and it is impossible to achieve the original accuracy every time the axis is changed. If multiple turning tools can be used at the same time, that is, the parts can be rotated around multiple axes without moving, this will greatly improve production efficiency and improve the accuracy of processed parts!
This method is called a multi-axis linkage CNC machine tool! Only with electronic computer control can multi-axis linkage become possible! If you want to process products with special shapes, this machine tool is the most suitable choice! It can be said that multi-axis linkage CNC machine tools are the Mount Everest of industrial mother machines!
This technology is mastered by advanced Western developed countries, such as Germany, the island countries, etc. The Batumi has restricted this type of machine and it must not be exported to the socialist camp! Unfortunately, with the defection of the island countries in the Western camp, these restrictions have become insignificant.
In the past, the Soviet Union used high prices to make the merchants of the island countries take risks and export these machines to the Soviet Union. But now, there is no need at all. The Soviet Union can directly import this advanced CNC machine tool from the island countries! This machine tool has an unparalleled advantage in processing advanced irregular objects!
Among them, the more important one is the propeller! The submarine propeller is a matter of life and death!
The propeller is the only propulsion device of the submarine. The pump-jet of later generations is not within the scope of discussion. In the early days, the propellers of submarines were all three-bladed. In order to achieve greater thrust, it is necessary to increase the propeller speed to stir more seawater. Increasing the number of blades of the submarine propeller can significantly reduce the propeller speed. You know, the higher the speed, the greater the noise. Therefore, the number of propeller blades of submarines is gradually increasing, from three blades to five blades, and from five blades to seven blades. For example, a seven-blade propeller has the thrust of a three-blade propeller, but the speed is only one-tenth of that of a three-blade propeller!
The number of propeller blades is always odd, because propellers with odd numbers are asymmetric and can significantly eliminate resonance. At the same time, increasing the skew of the propeller can also increase thrust, which is called large skew. This refers to the backward tilt of the blades, and the amount of this backward tilt is defined by the skew angle. A propeller with an angle between the centerline of the hub and the centerline of the blade greater than 25 degrees is called a large skew propeller. The skew angle of an ordinary propeller is only about 10 degrees.
Of course, the more blades, the better. The more blades, the more difficult it is to process! The seven-blade large side-slant propeller is the most suitable choice for balancing many aspects.
Such requirements result in the submarine propeller having a complex geometric configuration. Every detail of the design of this configuration will affect the noise and propulsion efficiency!
Soviet scientists also have extremely solid theoretical knowledge. They can use calculations to design propellers with the optimal shape to reduce cavitation, alleviate vibration, reduce noise, reduce rotation speed, and increase propulsion efficiency. However, after this propeller is designed, its manufacturing faces difficulties!
Since there were no multi-axis CNC machine tools, they could only process one plane first and then another. Even if the Soviet machine tool fixtures were unique, they still faced the problem of reduced accuracy due to this transformation. For a propeller, which is a large and precise device, an error of one millimeter would lead to a huge change in performance!
Now, with the arrival of the island country's equipment, Soviet submarine designers no longer have to worry about this problem! The precision of the propellers processed by the island country's equipment has fully met the requirements, which means that the underwater sound of Soviet submarines has been reduced by an order of magnitude!
For example, now, this Soviet nuclear submarine underwater has a cruising speed of 8 knots with the seven-blade large side-slant propeller at the tail, which only maintains a speed of 80 revolutions per minute!
With more than one rotation per second, the stirred water makes almost no additional sound, and the rotation of the two propellers can be seen clearly even with the naked eye!
Yes, there are two propellers. The submarine underwater is a Soviet-style cruise missile attack nuclear submarine, Type 949, codenamed Oscar by NATO!
Western nuclear submarines are either ballistic missile submarines or attack submarines, but Soviet submarines have another innovation besides these two types, which is cruise missile attack submarines! The only mission of this kind of nuclear submarine is to attack American aircraft carriers with the anti-ship missiles it carries. This is a killer weapon tailor-made for American aircraft carriers!
There are almost no submarines in the West with a displacement of more than 10,000 tons, except for the Ohio class. The Soviet underwater ghosts have many big guys, like this nuclear submarine, with an underwater displacement of up to 16,000 tons! (Depending on the model, the later model is 18,000 tons). It adopts the double-hull structure commonly used by the Soviet Union, with a width of several meters between the inner pressure hull and the outer non-pressure hull! Among them is the P-700 anti-ship missile, a killer weapon to counterattack the United States! This missile with a range of more than 500 kilometers is a weapon that makes American aircraft carriers tremble with fear!
At the same time, the double-layer pressure hull structure gives it good resistance to sinking. Even if it is hit by a torpedo, it can withstand it. Western submarines are all single-hulled. As long as they are hit by a torpedo, they will be completely damaged and may even sink.
As the Soviet Union's newest submarine, it has adopted various advanced noise reduction measures, including sound-absorbing tiles laid on the outside, various devices installed on shock-absorbing bases, etc., plus the low-noise propeller at the tail, it is simply an ocean black hole!
This is the first ship of the Oscar class. Thanks to the support of the island nation's advanced industrial technology, the construction progress was accelerated. It was put into service in March this year. At the same time, it is also the most secret weapon of the Soviet underwater force! The Americans didn't even know there was such an advanced nuclear submarine! (I can't find the numbers of the first two Oscar-class ships, so I'll name them K-146 for now.)