On the eve of the 2024 Chinese New Year, a rainy and snowy weather hit the southeast of China. The freezing rain and snow in some places have "added blockage" to the annual Spring Festival. In people's impression, the high-speed railways that are punctual and punctual have also been delayed in a large area, or even directly suspended.
But while some netizens were anxiously waiting on the high-speed rail, they saw the "green car" around them running all the way against the snow. Why is it that the high-speed rail, which looks more advanced, is not as good as the "old-timer" green cars?
Source: News screenshot.
How does heavy snow affect high-speed rail?
On February 4, the Weibo of the Wuhan Railway Bureau issued an announcement explaining the reasons for the large-scale delay of the high-speed rail in freezing rain and snow, mainly including three points:The catenary is covered with poor icing and conductivity, the switch is inflexible in ice conversion, and the snow train on the line runs at reduced speed.
Among them, the factor of snow cover on the line is very well understood, and we will focus on two other points: switch icing and catenary icing.
Source: Weibo screenshot.
The turnouts are icy
When high-speed rail trains change routes, they are also required like ordinary trainsChange the route by means of a turnout structure。The accumulation of snow and ice inside the turnout will affect the normal operation of the turnout.
Although some high-speed railways have a turnout snow melting device, the turnout structure may still fail in the event of extreme snowfall.
For example, the "Baolan high-speed railway" opened in 2017, in the first winter, there were 3 turnout failures due to snow and sleet on the turnout, which affected the normal operation of the train.
The recent sudden heavy snowfall also had an impact on the turnout structure. In this regard, the railway department immediately sent special personnel to deal with the snow and ice removal work of the turnout, and was on duty 24 hours a day.
Source: Weibo screenshot.
Thanks to the hard work of the railway workers, the problem of icing on the turnouts was quickly solved. But high-speed rail still faces another, more difficult problem - icing of catenary.
Catenary icing
Usually, when we talk about high-speed rail, the image of a bullet train comes to mind. But the "inconspicuous" wires above the high-speed rail are also an important part of the high-speed rail.
Unlike traditional trains, the power of high-speed rail is not traditional diesel, but electricity. This electricity comes from the high-voltage line above the high-speed rail car. The network composed of these high-voltage lines is called "catenary", or "overhead catenary".
High-speed rail can be connected to high-voltage lines through a structure called a pantograph. The pantograph takes the high-voltage electricity into the car, and after the step-down treatment, it is used to drive the high-speed rail.
The pantograph above the high-speed rail carriage, ** from the documentary "China's High-speed Rail".
But if ice appears on the wire, the contact between the bow head and the wire will be affected. Some people see high-speed trains driving all the way and releasing "lightning effects", which are caused by the ice between the bow head and the power lines.
In addition, ice on the wires can also make the wires heavier and wobble more. In order to obtain current as stably as possible, the high-speed rail train can only reduce its running speed, and in serious cases, it can only temporarily stop and wait.
If you want to solve this problem, the method is also very simple and crude, that is, de-icing. Although engineers are working on automated de-icing equipment. However, at this stage, the fastest and most direct way for this large-scale catenary icing is manual removal.
Use an ice pole to de-ice,** News screenshot.
Under the influence of these factors, high-speed rail trains have to run at reduced speed, which leads to a decrease in the utilization rate of high-speed rail EMU vehicles. As a result, there have been a lot of delays and outages.
What exactly does "passenger green car" mean?
When the high-speed rail stopped on the road, many netizens took pictures of the "green car" whizzing by. So why are green cars not afraid of heavy snow?
First of all, let me explainThe green car we often talk about is actually the common name for the train with the body painted green. Moreover, what we call a green car today is very different from the green car we talked about more than ten years ago.
More than ten years ago, we often talked about green cars, which were "old green cars". These green cars refer to very old types of railway coaches, such as the Type 22 or some of the Type 25B.
The typical characteristic of these "old green cars" is that they are slow, and most of them do not have air conditioning, and people often have to open their windows to breathe in the hot summer.
More than a decade ago, if you were on a train with a K (fast), Z (direct), or T (express), you might have seen some orange and blue painted bodies. These "orange cars" and "blue cars" tend to be better equipped than the "old green cars", they are basically equipped with air conditioning, and they often run faster than the "old green cars".
However, since 2014, the railway department has decided to use dark green as the unified color of ordinary speed trains (non-high-speed rail EMU trains), and began to repaint the color of the train body in that year. The previous orange and blue painted trains have gradually become "new green cars".
So, don't equate the "new green cars" on today's railways with the "old green cars". The speed and comfort of the "new green car" may indeed be inferior to that of high-speed rail, but it is still much more comfortable than the early "old green car".
Although the number and capacity of the "green car" are far less than before, and the name "green car" sounds like "abandoned by the times", the "green car" has not abandoned the times. They can still be seen on railway lines across the country, and for areas that have not opened high-speed rail for the time being, "green cars" are still important.
At the same time, in this year's Spring Festival, at the critical juncture of the large-scale delay of high-speed rail operation, the "green car" also shuttled in the heavy snow, transporting wanderers who were eager to return to their hometowns one by one.
Why the green car
Can you "brave the snow"?
To be sure, green cars are of course also affected by icy turnouts and snow on the routes, but becauseIts driving speed is relatively slow, coupled with the overnight emergency repair of railway workers, these problems have little impact on the driving of green cars.
In addition, there are different types of power**, some are purely electric like high-speed rail, some are driven by internal combustion engines, and some are driven by steam engines.
Therefore, the most serious impact on the high-speed rail EMU is "catenary icing".It has little impact on the "green cars" that are powered by internal combustion engines and steam engines, this is the scene where the high-speed train stops on the side of the road and waits, while the green car roars by.
Popular Science China).