Indian Railways (IR) has come a long way since the started in 1853. And bold and innovative steps have been taken to bring it to world-class standards, since 2015…
First time since 1947, IR has a technocrat as Railway Minister, guided and supported by a decisive and visionary Prime Minister.
Complete electrification of railway traction, construction of dedicated freight corridors, makeover of hundreds of railway stations, Testing Track in Rajasthan, RRTS in Delhi, bio-toilets, and Semi High Speed Vande Bharat trains are positive steps. More importantly, the rapid implementation is the most welcome change from the slow pace before 2015.
The “Deccan Queen” inaugurated on 1 June 1930 ran at an average speed of 100 kph between Mumbai and Karjat, indicating a maximum speed of about 75 mph (120 kph) at least for part of the journey. From the start, the maximum speed of trains in India was 60 mph (96.6 kph). The electric locomotive designed for this service was rated for 87 mph (140 kph).
From November, December 1955 to January 1956, the first high-speed train trial was conducted. Results were published in.No. 54 Dynamometer Car Report. Not much came out.
Second trials were conducted in the late sixties and reported in RDSO C&M 1. The trials led to the introduction of “Rajdhani Express” trains with improved track quality and, as coaches and locomotives with higher speed potential became available, “Shatabdi” and “Gatiman” express trains on specific routes with maximum speeds of 130/150/160 kph.
To introduce a high-speed train based on the “Electric Multiple Unit” rather than a locomotive-pulled train, “Train 2018” was renamed “Train18”.
The train was renamed “Vande Bharat Express” to honor the Prime Minister’s “Atmanirbhar Bharat” vision of indigenous design and manufacturing. The Prime Minister launched the run from New Delhi to Varanasi on February 15, 2019. Indian Railways has introduced several improved Vande Bharat trains since then.
Vande Bharat trains can reach 180 kph, slightly slower than the 1997 WAP 5 locomotive.
All these efforts are commendable, but the author has some concerns about Indian Railways’ technical standards, including:
Ride Index LHB (Fiat) Bogie Casnub Bogie Track Standards & Quality
Ride Index
Ride Index is a hyperbolic scale of 1 to 5 that measures a train’s ride quality. No 1 means “Very Good” appreciation. No 5 means appreciation is “Dangerous Likely to Derail” as typical. For main line and EMU passenger coaches, IR recommends 3.25 RI and 3.5 & 4.0 as limiting values. The preferred and limiting acceleration values are 0.30g and 0.35g.
0.35g matches “Chartet’s Formula,” a borderline case. Normal humans can tolerate acceleration levels between 0.8 and 1.3 m/s/s, with the average being 1.0 (0.102g).
Choose your own conclusion. Indian Railways issue “Speed Certificates” without mentioning Ride Index, saying only that “the ride is satisfactory.”
The ubiquitous “ICF All Coil” bogie suspension of passenger coaches could only reach 130 kph on specially maintained track.
IR chose a new coach and suspension system. LHB’s coach with FIAT bogies was designed with a main frame without head stocks to reduce bogie rotational inertia and “yaw” oscillations.
First 24 coaches were tested for ride quality and found disappointing. “Yaw Dampers” improved ride quality.
However, the author believes that the bogie wheel base-to-track gauge ratio was completely ignored. World railway bogie designs show this ratio is around 1.75 / 1.8 or 2.0.
Since FIAT bogie was designed to accommodate standard and broad gauge differences, it is 1.5274.
For different reasons, Vande Bharat bogie has a 2,700-mm wheel base compared to FIAT’s 2,560. Vande Bharat can reach 200 kph. Vande Bharat bogie ratio is 1.611.
Unfortunately, adopting a new bogie with a larger wheel base is too late. IR may fit Vande Bharat bogies to LHB coaches.
Replacement of the “BOX” bogie with Casnub bogie was based on ease of maintenance. The American “Three Piece Truck” bogie design was controversial from the start, with many zonal railways reporting track structure damage. Several derailments required RDSO to install a lower spring plank and place elastomeric pads between the axle bearing and side frame. RDSO published a small booklet titled “Taming of The Casnub” by Mr. K B L Wadhwa. One wonders why the bogie had to be “Tamed” if the selection was thorough.
Author believes choosing a bogie with a large unsprung mass in the form of side frames was wrong. When Y25 bogie, a great design, was also competing. Comparing to American Railroads is rather unfair. US railroads use high axle loads, but their track structures are stronger than Indian Railways’.
It is universally accepted that large unsprung masses degrade track quality. Casnub bogie damage cascades on track structure, making the ride rougher as the damage increases. IR operates the world’s most intensive network, making it difficult to obtain “Power Blocks” of sufficient duration for track maintenance, despite the manual. When the goal is to run trains faster than before, this is not ideal.
A “Y25” bogie with a low un-sprung mass that works for loaded and empty wagons would have been better. Such bogies are the backbone of European railways.
The 1955/56 and 1969 trials for high-speed trains in India recommended track quality improvement and maintenance standards based on RDSO report C&M 1. The Indian Railways Permanent Way Manual specifies track parameters like alignment, unevenness, twist, gauge, and more. After a long and enjoyable association with IR, the author has observed that standards are set more on “what can be achieved during normal course of working without any additional efforts” than on setting higher standards and then achieving them. There are also references to “few occasions” and “isolated instances” without specifying time or length units.
It is pleasing that the redrafted IRPWM and publication in June 2020 addressed some of the issues and improved deviation values and measurement chord lengths. The maximum allowed speed of tracks now limits the operation of high-speed trains to a few routes, and even these routes operate at much higher capacities than designed, hindering their throughput.
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