"Mushrooms" grow on train tracks. Netizen: Can you eat them? Official popular science: this is the dowty retarder

Some attentive friends discovered that some "iron mushrooms" grew on some rails, which were shiny and bright, and they would make "ding, ding, ding" percussions when the train passed by.

It turns out that this is the dowty retarder, which is installed on the steel rail and contacts the wheels by sliding the cylinder cap head to brake and decelerate the freight vehicle.

According to reports, this type of dowty retarder body is filled with nitrogen, which can make the "mushroom" grow taller quickly through compression. If the speed of the incoming vehicle is higher than their set critical speed, the "growth mushroom" will apply to the vehicle together. Resistance, so as to achieve the effect of decelerating the vehicle.

What's interesting is that because of the existence of the dowty retarder, there are still a group of people on the railway called "Mushroom-stomping gentlemen". They are maintenance workers of the retarder, and they need to inspect, inspect and repair the retarder installed on the line, and "stepping on the mushroom" is one of the important links.

According to the maintenance worker of the dowty retarder: "It should be a little laborious to step on a roof. If it is easy to step on, it is obviously insufficient oil and gas and there is a problem."

When a faulty dowty retarder is found, the maintenance worker should replace it in time, and bring the faulty retarder back for maintenance, including disassembly, cleaning, pressure, oiling, assembly, and nitrogen filling.