VACCUM BRAKING AS A CONTINUATION:Vaccum braking is now almost extinct in BG, as far as i know VB does not exist in BG currently, however a recently spotted board after Bangalore Cantt towards Bangalore city shows two different speed restrictions for AB and VB respectively, therefore i was skeptical on VB existence in BG..
Here it goes.....
The ejector in a loco plays a vital role in vaccum braking of a train, there is a single train pipe in the total formation in which vaccum is maintained, upon use of the ejector vaccum...
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is maintained all over the formation. When brakes are applied the atmosphere air is admitted into the pipe therefore creating a layer of vaccum above the piston and air below. This pressure differential forces the brake piston to move and deaccelerate the train however this type of braking has far too many disadvantages therefore is less preffered over AB.
Railfanning Note: In air braking system green color over the pipe indicates the BRAKe PIPE while white indicates the FEED PIPE.