Recently, the 12000 HP WAG12 locomotive has been inducted into service by the Indian Railways. This will definitely give a fillip to heavier freight trains. For freight operations, fewer heavier trains are better than a large number of not so heavy trains.
However, the questions that arises is: Do we need heavy locos for heavy trains? Or, is it better to have two or more less powerful locomotives in multiple operation?
The Indian Railways do run trains with locomotives in multiple operation but the tendency has been to have one or at best three locomotives per train. There is a view, quite common on the US Railroads, to have 5 or more locomotives per train. These locos need not all be at the head of the train but can be distributed along the length of the train so that coupler forces are minimised. With remote multiple operation possible through systems like locotrol, you need only one crew on the lead loco. The advantage of this is that even if one locomotive in the consist fails, the train can be worked to the next destination with the remaining locomotives. Thus, you have a loco failure but not a train failure. With a single loco or even two locos, the train will fail along with the loco. It is obvious that in train operations, a train failure in mid-section is disastrous and blocks all traffic on the line.
There are other pros and cons of having a single high horse power locomotive as compared to a number of lower horse power ones on a train, but the avoidance of a train failure is perhaps the most important one for going in for a larger number of locomotives per train.