Railway tunnels, are generally

In the wooded bulk-head, used for mucking in steep grade tunnels,

The tunnels, the artificial underground passages are constructed for :

For full face method, the excavation to be done is generally divided into

For initial surveys of tunnels, the following activities are involved:
1. Marking portal point with concrete pillars on the ground
2. Marking tunnel obligatory points on the topographical maps
3. Preliminary setting of the tunnel on the topographical Survey of India maps
3. Driving lines between the fixed obligatory points.
The correct sequence of the activities is :