Railway Engineering
A treadle bar is used for

interlocking points and signal
setting marshalling yard signals
setting points and crossings
track maintenance

ANSWER DOWNLOAD EXAMIANS APP

Railway Engineering
A triangle is used for

Separating all the sidings and shunting lines from main lines
Transferring wagons to and from parallel tracks without shunting
Preventing the vehicles from running off the track
Changing the direction of engine

ANSWER DOWNLOAD EXAMIANS APP