Russian fighter jet escorts Chinese President Xi's plane

A Russian fighter jet is seen from the cabin escorting Chinese President Xi Jinping's plane before it lands in Kazan, Russia for the BRICS Summit.

Xi is in Kazan, the capital city of Russia's Republic of Tatarstan, to attend the 16th BRICS Summit, at the invitation of Russian President Vladimir Putin.

Xi is set to attend small- and large-group leaders' meetings and the BRICS Plus leaders' dialogue, and will deliver important speeches. Xi will also have in-depth exchanges with other state leaders on the current international situation, practical BRICS cooperation, the development of the BRICS mechanism and other important issues of common concern.

Xi's entourage, including Cai Qi, member of the Standing Committee of the Political Bureau and director of the General Office of the Communist Party of China (CPC) Central Committee, and Wang Yi, member of the Political Bureau of the CPC Central Committee and foreign minister, arrived on the same plane.

BRICS is an acronym for Brazil, Russia, India, China and South Africa. The upcoming summit is the first to be held after the BRICS expansion in January when Iran, Egypt, Ethiopia, Saudi Arabia and the United Arab Emirates were included into the bloc.

Russian fighter jet escorts Chinese President Xi's plane

Russian fighter jet escorts Chinese President Xi's plane

Russian fighter jet escorts Chinese President Xi's plane

Russian fighter jet escorts Chinese President Xi's plane

Russian fighter jet escorts Chinese President Xi's plane

Russian fighter jet escorts Chinese President Xi's plane

China's development of a next-generation bullet train able to hit an operation speed of 400 kilometers per hour (km/h) was the result of the country's determination to continually push the standards of locomotive technology to the next level, according to Zhao Hongwei, one of the senior researchers behind the achievement.

On December 29, 2024, the prototype of the CR450 train made its debut at the National Railway Test Center in Beijing, captivating the world with its sheer speed.

Prior to this, test trains equipped with the CR450's cutting-edge technologies had already clocked an astonishing single-train speed of 453 km/h and a relative crossing speed of 891 km/h on the Fuzhou-Xiamen high-speed railway's Meizhou Bay Cross-Sea Bridge, setting new global benchmarks.

As chief researcher at the China Academy of Railway Sciences, Zhao and her team is behind the entire R-and-D process of the Fuxing high-speed train series, having developed a train network control system -- sometimes called the "brain" of EMU trains.

China Railway said efforts to raise operational speeds to 400km/h started in 2018, and production of the prototype officially began in 2024. It was Zhao's job to work out a master plan to increase the speed of bullet trains, tackling challenges from cost performance to technical feasibility.

The new model will be significantly faster than the CR400 Fuxing high-speed trains -- still the world's fastest of its kind by far with an operation speed of 350 km/h.

"We have posed several top-level technical objectives for CR450 EMU trains, including higher speed, better security, higher energy efficiency, more comfort and higher intelligence," Zhao said.

In the development process, researchers were tasked with determining not just how to make a faster train, but improving China's locomotive technology in such a way that would most benefit its already vast network of railways that may currently be limited to lower speeds.

"In 2018 we compiled some statistics, and there were about 10,000 kilometers railway lines where trains could run at a speed of 350 km/h. How can we raise the speed while making full use of the existing railways, that is a question. It can bring the greatest benefits when line conditions are relatively consistent but equipment is upgraded. We have done some market surveys that found the improved speed will bring a huge edge to our overall rail service market," explained Zhao.

The CR450 train resembles an arrow when viewed from the side and weighs in at about 10 tonnes, making it more than 10 percent lighter than its predecessor. Such efforts contributed by the large-scale adoption of carbon fiber and magnesium alloy, though, were not enough to achieve the energy objective.

To increase the speed from 350 km/h to 400 km/h, Chinese train designers had to deal with the surging energy consumption brought by a 30 percent increase in air friction. Zhao said that her team adjusted the slenderness ratio of the train head to reduce the friction by 22 percent.

Balancing the need for weight reduction and noise control has also been a delicate dance. Zhao described the meticulous calculations required to ensure each component meets the stringent technical specifications.

"We want to ensure that both the weight and noise are reduced, so what follows is meticulous calculation. Main engine enterprises have required their suppliers cut the size and weight of each component while meeting certain technical standards," Zhao said.

The CR450's innovative features extend to its traction system, which for the first time in China's high-speed rail history, will utilize permanent magnet motors. This technology boasts an efficiency improvement of more than three percent over the asynchronous traction motors used in the CR400.

Safety is always of the utmost importance for passengers, especially with the dramatic increase in speed, Zhao emphasized as she explained why the operational speed must be capped significantly below the train's true top speed.

"If the traction system does not work, the worst-case scenario would be that the train can't move. But if the brake system fails, the train will not stop, posing the biggest safety risk. So we now require that when the train runs at the speed of 400 km/h, the braking distance has to reach 6,500 meters, which is the same distance as our CR400 braking at 350 km/h," she said.

The development of the CR450 has been a true collaborative effort, involving over 100 companies responsible for the design and production of the train's components, and more than 2,100 enterprises participating in the overall process.

Zhao emphasized the importance of constant communication and innovation to overcome the challenges posed by the ambitious technical targets. "Sometimes people are not likely to explore other technologies if the existing technology is widely adopted and mature. But if you want to meet higher technical requirements for the train, you must adopt new technologies. You have to break through and innovate, because there is no longer mature experience abroad to learn from," the researcher said.

The CR450 EMU, like its predecessors, has completely independent intellectual property rights, and it is also necessary to establish a "Chinese standard" on this basis.

"We already had full intellectual property rights in the CR400 trains. Our entire research and development system and testing system are in fact very complete. So we have the ability and confidence to carry out research on higher speed EMU trains," Zhao said.

China Railway said on Sunday that the next step is to put the prototype through a series of line tests and assessments to further assess its performance. The cutting-edge bullet train could be up for running on China's high-speed railways in a year or so.

China has the world's biggest high-speed rail network, with 48,000km of lines in service connecting 31 provincial-level administrations, catering to over 2.2 billion passengers.

China builds world's fastest high-speed train through unremitting innovation: engineer

China builds world's fastest high-speed train through unremitting innovation: engineer