At this point, we complete half our trek and turn back. We now take the tunnels 24C and 25C to reach Khandala. This is the Monkey Hill side portal of the 350 meter long tunnel 24C. This unidirectional tunnel has the single line and is used only by the Down (climbing) trains. You can see the older Up and Mid lines that pass on the right of the tunnel. Note the vertical rails on the right of the portal – these probably arrest any rolling boulder from reaching the Up and Mid lines.
One has to extremely cautious inside these and indeed all other tunnels. One is warned of a train’s approach only with a few tens of seconds to spare. There are refuges carved the side of the tunnel and walking through these single line tunnels is essentially jumping from refuge to refuge. In case a train arrives in these single line tunnels, one may not have the luxury of making it to the nearest refuge, so a standing in a gutter might be the only option.
The only time one can walk easy, is when a train has just passed – you then have at least ten minutes before the next steel snake arrives.