Bhopal Shatabdi: chalti hai ek dum hawa ke mafik, speed aisi ke ruka de traffic - Varun

A COMPILATION OF RAIL SIGNS AND THEIR MEANINGS:
Compiled by me thanks to years of railfanning experience after reffering to many people and online material, I would quote an example with every sign to aid in understanding to the best extent possible:
The first thing we are concerned about when we are talking about movement of trains is anything which makes the train to de-accelerate, they can be in the following instances.
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PERMANENT SPEED RESTRICTION-A restriction of speed in a particular section (which otherwise is a faster speed permitted one) of a permanent nature, usually placed before steep curves, weak P.Way etc. This is apart from obvious restriction zones like that of loops at a station.
Ex: Permanent speed restriction of 80 KMPH at sirnapalli forest gradient between Uppalvai and sirnapalli stations in SC-NED-MMR line, similar can be found in many sections.
A TEMPORARY SPEED RESTRICTION-A restriction of speed which is imposed temporarily due to varied reasons like P.Way work or other reasons. A typical instance is imposition of speed restrictions before many unmanned LC’s of HYB division of SCR between DHNE-KRNT-KCG-NZB-MUE(Probably to allow better control to LP in case of a confused soul deciding to cross an LC with his road vehicle at the last moment)
Ex: Speed restrictions at Makalidurga ghat between YNK-DMM for up gradation of P.Way.
THE SIGN(for both of the above restrictions): The sign board indicating the speed to be followed would be a Triangular yellow board with speed mentioned in black, usually of reflective material to be visible to LP at night. The train needs to be at the designated speed mentioned on the board by the time it passes the board even though it is typically placed some 100mts before the actual caution abled section. Apart from the board, these cautions would already be mentioned in the Caution order given to the LP before moving the train in a particular section. Again, the crew running a train in a particular section would already e having Road learning without which they are not authorized to pilot a train. So this leaves us with the crew already knowing the restriction, we can travel rest assured as far as risks involved with overspeeding at restricted zones are concerned.
RESCTRICTION TERMINTAION: A restriction in place obviously means it would have to end somewhere, be it permanent or temporary, a large circular yellow board with a black T(again of reflective material) would be placed indicating the termination of restriction. In specific cases of Passenger and goods trains, T/P and T/G boards are placed(T/G usually after T/P as goods rakes tend to be longer) indicating termination of speed restriction of passenger and goods trains.
Railfanning Note: After a restriction is terminated while train is on a curve, one can find the display of flags by Guard and ALP, it’s amazing to see this sight especially in diesel locos accompanied by the chugging/buzzing(For Alcos and EMD’s respectively) and vigorous waving of flags.
I understand many of you must have seen this earlier, if not please try to watch the strict compliance of speed at restrictions and terminations, not to forget the display of flags/Lights.
I hope this has been useful, please keep adding while I add some more too, For a knowledgeful and safe railfanning Experience.
Cheers.