Question about London underground trains please.?

Question

Was on a newish underground train in London today.
There is a pressure gauge visible in the carriage near the  'join' where the train articulates. It is graded 0-10 bar, obviously a mesure of 'pressure'. It seems to read zero with the train moving rising to about 4 when stationary.
Can anyone tell  what this gunge relates to and what it is measuring?
Thank you.

Anonymous · Accepted Answer

It's the brake air pressure gauge.

PQR Theorist · Answer

Before the train enters service, the operator applies the brakes then walks through the train to check that there is air pressure showing in each car; this simple test ensures the brakes are working all through the train.

Bill · Answer

It is the car release valve

Zheia · Answer

It measures overcrowding pressure.

Anonymous · Answer

Brake pressure indicator.

Anonymous · Answer

I would guess it relates to the pressure in the brake chamber

Timbo is here · Answer

. Air pressure, measured by the gauge, is used to operate the wheel brakes

Question about London underground trains please.?

7 Answers