What's that extra set of colour discs below the signal arm? Never seen it before...

SPI means Shunt Permitted Indicator.However,conventional Shunt signals like the one mounted on the main post are also called SPIs.However the function of the special signal is difficult to guess unless the yard layout is studied closely or maybe someone could ask the station staff?It seems the signal is an improvised unit and has a mesh grille on both the sides which implies that its meant to be visible from both sides?One purpose of the SPI may be to indicate the route and is displayed in conjunction with the shunt signal.

This is a Shunting Permitted Indicator (SPI) and works in conjunction with a stop signal or a shunt signal. The SPI shows a yellow cross illuminated by light and authorises the Driver to shunt past the associated stop/shunt signal in the ‘On’ position. A proceed hand signal must always be shown at the signal.

Hey Pawan. The line officially starts just after the Ernakulam Town-Kottayam line bifurcates from main line. But the line is not used there. This marker is situated there. The line is used fully after Ernakulam Marshalling Yard. These lines look unused but are defenitely used. This line bends sharply to left just before Trippunittura

Jimmy, do these lines run all the way upto KRL? Where do they start from..Tripunithura? When I used to travel towards FACT in Ambalamedu, I only used to see some unused rusting lines next to KRL. I didn't know if there were some other newly laid lines up to KRL.

Nice capture.

It is for coasting,long down gradient ahead.There should have been a triangle painted in black below the arrow mark.If I remember correctly,I have seen such a sign in NGP-ET section 2years ago !

I think it means do coasting as a down gradient ahead

coasting , continuous down gradient, the driver may notch down to zero and coast.

Taken by Ajai Banerji, Sep 2005. I forgot to put my name earlier.