"Iron mushrooms" grow on train rails? Official popular science: this is 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" knocks when the train passed by. It turns out that this is the legendary dowty retarder, which is installed on the 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 "mushrooms" grow taller quickly through compression. If the speed of the incoming vehicle is higher than their set critical speed, the "growth mushrooms" will apply to the vehicle together. Resistance to achieve the effect of decelerating the vehicle.

What's interesting is that because of the existence of dowty retarder, there are still a group of people on the railway called "Mushroom-stomping gentlemen". They are dowty retarder maintenance workers who 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 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.