IR’s confusing traction rolling stock policy

IR’s Confusing Traction Rolling Stock Policy

Over the past two years, Indian Railways began pushing for 100 per cent electrification of its routes. The project is targeted for implementation over the next decade.

In preparation, manufacture of electric locomotives has been ramped up by IR’s multiple manufacturing units. The Diesel Locomotive Works (DLW), earlier manufacturing diesel locomotives, is also now churning out electric locomotives.

Simultaneously, IR is also delving into several kinds of electric locos. However, there is no clarity on IR’s long-term vision with respect to its manufacturing policy for electric locos. The projects that IR is undertaking currently, signal trial and error rather than clarity of thought.

Consider this:

1. Development of aero-dynamic WAP-5 locomotive for high speed operation. However, only one unit is in service.
2. One high speed WAP-7 was turned out, fit for 160 kph, despite the well-known fact that the suspension of a WAP-5 is more track-friendly than the WAP7 at higher speeds.
3. Two sets of multiple WAP-5 (single panto operation) were running for a long time with several trains. Trials were reported as a success across the desired parameters. And yet, no important or high-speed train has been given these locos on a permanent basis.
4. IR is now targeting the running of push-pull superfast and Rajdhani class trains.
5. IR is pushing the production of train-sets on a big scale.

While trainsets are likely to dominate 20 years hence, the vision and policy outlook of the Railways does not appear to be clear or focused for the next decade.

The roadmap towards an increase in absolute and average speed of trains is far from clear as different entities responsible for this are not seen moving in sync. This is despite clarity in the aim of increasing absolute and average speeds of all trains.

IR should consider going for the tried and tested push-pull format for increasing speeds, besides reducing running time of trains through increased power available for a train.

The Mumbai-Delhi push-pull Rajdhani, powered by twin WAP-7 locos, maintaining timings over a congested route dotted with multiple ghat sections is a case in point.

However, for future push-pull trains on non-ghat section routes, IR should consider only using the WAP-5 locomotive for high speed trains and the Rajdhanis. The benefit of WAP-5s is more track-friendly suspension at higher speeds. The power of these locomotives is sufficient for the load as well as current speeds.

Hence, rather than channel funds towards developing more high-speed WAP-7 locomotives, IR should concentrate on increasing production of WAP-5 locos complete with Train Protection and Warning System (TPWS) and other auxiliary equipment to make it fit for high speed operations in the range of 160 kph.

Possible method of implementation

All these locomotives should be pre-configured for push-pull operation.

At the same time, all new coaches being manufactured should have push-pull capability by way of provision of requisite communication cables through the train. Existing LHB coaches should be modified for push-pull working in their respective maintenance depots. The above measures will go a long way in increasing the average speed of passenger carrying trains on IR. Trains will accelerate better after halts and slowdowns for speed restrictions and other reasons.

Another benefit of push-pull operation is that platforms need not be lengthened. This is because the rear loco can remain outside the platform without any inconvenience to passengers.

Notes:

1. Most locomotives have Traction Motors which actually drive the wheels. The method of fixing the traction motors inside the bogie frame determines how much stress is delivered to the track by the loco. If the traction motors are entirely fixed to the bogie frame, this will improve suspension as the springs in the bogie will absorb shocks to a great extent. However, at times, the design is such that part of the traction motor rests directly on the axles. This means that there is no spring in that part to absorb shocks, thus delivering greater stress to the track.
   
   The WAP-7 locomotive, a modified version of a freight locomotive, has partially suspended traction motors. On the other hand, the WAP-5, though having lower power, has fully suspended traction motors which deliver lower stress on the tracks and hence are more track friendly
   
   
2. IR also modified a pair of WAP-5 locomotives to draw power from a single panto raised on only one of these locomotives. These locos ran in multiple-unit operation with both locomotives being controlled from the front loco. This format was also a success in trials and revenue service. Single-panto operation ensured that no instability was inserted in the overhead wires during high speed running of the train.