The industry claimed that the bird hit the high iron common

At around 11.55 a.m. on June 2nd, the high-speed rail from Hangzhou to Beijing was forced to stop at Nanjing South Station because the cockpit front windshield was cracked by an unlucky “bird”.

As for the reasons for parking, the railway explained that the cracking of the front windshield would have a definite impact on the driver's line of sight. In addition, when the train is moving at a high speed, it is likely that the second “injury” cannot ensure safety. To prevent potential safety hazards, it is necessary to focus on monitoring. Front part.

According to our reporter’s interview, it is not uncommon for high-speed trains traveling at high speeds to encounter accidents such as “flying birds” and other UFOs crashing into pieces.

“The front windshield with remedial and auxiliary functions, without the installation of a safety membrane, is also one of the hidden dangers of high-speed rails.” A person approaching the railway system is introduced.

Dangerous UFOs

"For high-speed trains, what strikes them has bullet-like power," said a doctoral student in the Department of Physics at Tsinghua University.

If the current maximum speed of the train is 300 kilometers, then a half-dozen of pigeons can reach 5000 Newtons after hitting the front windshield. Even if the train is slightly slower, it is estimated that there will be about 3000 Newtons. , which is equivalent to using 300 kilograms of weight on the glass.

"The greater the speed, the greater the quality and the greater the impact on the glass." said the doctor said above Tsinghua.

“In order to ensure the safety of passengers in the car, special glass or safety membranes must be used to block the impact so that even if the glass is damaged, it cannot be penetrated.” The above person further introduced.

In fact, according to our reporter’s interview, the front windshield of the CRH380 series high-speed train such as the G38 is equipped with a super bullet-proof deceleration glass and an anti-collision device.

According to Shuguang, deputy director of the National Security Glass and Quartz Glass Quality Inspection Center, the current front end of the high-speed rail is laminated glass, which is a combination of three layers of inorganic glass and two layers of soft plastic. The last layer is 2~ 3 mm splash protection layer, even if the first 5 layers are broken, the splash-proof layer will wrap the impactor like a net.

Indeed, the above-mentioned person approaching the railway system introduced that from the actual situation of the accident, glass did not involve quality problems, and the impact of the birds stopped before the last layer of glass, preventing the penetration. This high-speed rail front glass uses the first five layers of cracking, deformation, and other processes to absorb the impact energy, so that the impact energy will be the last piece of glass to crack and splash.

"However, if the impact energy is larger, the bird will be bigger and the speed will be faster. The probability of the train breaking will be very high. Once it is broken, the flying object and the broken glass residue will endanger the safety of the driver and passengers. ”

According to the tests done by Dawning and his team many times, even if the speed reaches 400 to 500 kilometers and encounters a flying stone impact weighing 1 kilogram, the front windshield of the high-speed rail will not be broken.

However, in order to ensure safety, the above-mentioned person approaching the railway system reminded that the trials should particularly consider the opposite situation of the two vehicles, that is, the actual impact force is at least 350 kilometers + 180 kilometers = 530 kilometers per hour.

A person in the field of high-speed rail disaster prevention told reporters that the frequency of actual bird strikes in high-speed rail is much higher than the public knows. The reason why the public is unaware of it is because the bird hit the high-speed rail glass if the train speed was not at that time. The highest gear position is not destructive to the glass and will not affect the driver's line of sight. The train will continue to travel. Even if there is a big damage, the train will slow down at most. Passengers generally do not know what caused the deceleration.

“The impact of the general public’s informed incident was mostly caused by the severe damage of the front windshield, which caused the train to stop and even transfer. Now that Weibo and other media are well-developed, passengers live on the Internet and things are immediately apparent to the world.”

Remedy

"Although accidents are more common, the railway departments generally do not disclose them." The above-mentioned persons approaching the railway system also revealed that, however, the railway department often convenes some people in the industry to discuss solutions.

"Every time the causes and countermeasures of the analysis of the accident were similar, they all attributed the problem to the standard problem." The above-mentioned person analyzes that the glass's internal purchase price is between 1500-300,000.

According to the above-mentioned sources, one of the hidden dangers of the front glass of high-speed rail is that no safety film is installed on the innermost layer of the front glass of the high-speed rail. “The glass technology involving super bullet-proof deceleration can pass through the glass without major improvement. The way to install the security film in the innermost layer is solved."

The safety film technology is a remedy and auxiliary for the existing high-speed rail front glass. After installing the safety film on the innermost side of the existing high-speed rail front glass, it can minimize splash damage or even eliminate splash hazards.

It is reported that the current security film technology can already reach 6-8 mm thick ordinary glass to withstand the shooting of 64 pistols. If a bird with a larger contact area impacts, only a 6 mm single piece of glass can achieve more than 1000 security films. Joule's resistance to penetration, that is, the posting of a qualified safety film, can increase the penetration resistance of the high-speed rail front glass by more than 1,000 joules. From the current actual use of these vehicle front windshields, the safety membrane can improve the anti-penetration index by 20-30%.

“Unfortunately, there is no mandatory standard for the automotive vehicle safety film market in China. The “CAS 140-2007 glass safety film standard” issued in 2007 belongs to the Association standard, and companies only voluntarily adopt it.” The above-mentioned sources introduced the current high-speed rail No safety film was installed on the innermost layer of the glass barrier.

In addition to installing the security film, what remedies?

“When the bird crashed, it was already too late. It was too late,” said the industry person in the field of high-speed rail disaster prevention.

He said that the speed of the HSR is already approaching the speed at which the aircraft took off, so it is necessary to refer to the protection standards in the aviation sector and implement special protection measures for birds in the airspace around the railway. At present, the airport's active bird strike prevention and control is mainly to drive birds away from the airspace of airports. The main ways to drive them are intimidation, destruction of habitat and migration of habitat.

"Aviation is big in airspace, high-speed rail is long, but it is only on both sides of the line, so the cost of doing such protection should not be too great, and such protection does not require too many cutting-edge technologies and can be introduced through aviation. The current practice in the field can be slightly modified.” The source said that the current obstacle is not the technology, but the question whether the department concerned or not.