And how foolish are they to say that doubling does not improve the efficiency. In my travels i have always encountered one or two crossings in the Ghats itself and then one freight awaiting my train to arrive at either QLM or CLR. And those awaiting for crossings itself wastes fuel and time. And many times I have seen even passenger trains made to wait for crossing in the Ghats thus delaying an on-time train.
Even a child can make out the fact that having two lines running in opposite directions reduces train delays thus saving fuel and time which is efficiency in my opinion.