rihanna sang baby this is what you came for.
rihanna sang baby this is what you came for.
who sings baby this is what you came for?
rihanna
Na
Na
bullet::::- the automatic vacuum brake. this system was similar to the simple vacuum system, except that the creation of vacuum in the train pipe exhausted vacuum reservoirs on every vehicle and "released" the brakes. if the driver applied the brake, his driver's brake valve admitted atmospheric air to the train pipe, and this atmospheric pressure applied the brakes against the vacuum in the vacuum reservoirs. being an automatic brake, this system applies braking effort if the train becomes divided or if the train pipe is ruptured. its disadvantage is that the large vacuum reservoirs were required on every vehicle, and their bulk and the rather complex mechanisms were seen as objectionable.
railway brake