RWF Report

1. 13
th
August, 2016 (Copyright 13/08/16 Abhigyan nath)


A brief report on the industrial visit to the Indian Rail
Wheel Factory (RWF),Yelankha,Bangalore-560084
-Conducted by the IEEE young professionals (Bangalore section)
The Wheel and Axle plant at Bangalore was founded in 1984 to cater to the massive needs of
the Indian Railroad Industry as India had to be self sufficient to effectively manage the largest railroad
network it would grow to be in the coming years. True to its vision the Indian Railways today has a
~38,000 km rail network around the country which makes it an absolute lifeline to India. It was later
renamed as the Indian Rail Wheel Factory (RWF) as we know it today. It is spread over an area of 119
acres of lush green land which make it one of the most eco-friendly factories in India. Also, not to
mention that within the factory there are two water tankers which are the largest water tankers in
south-east Asia.
We, as young engineers and the future generation citizen of India were given this wonderful
opportunity to visit this State-of-the-art manufacturing and production unit of the Indian Railways and
interact with the engineers and employees who perform this tideous task with utmost precision and
accuracy and are able to supply wheels and axles of magnificent quality,durability and dependability.
These materials are processed through rigorous testing mutiple times throughout the entire
manufacturing periods and very strict quality checks keep erroneous products at bay. It was truly an
amazing first hand experience of the methods used in industrial manufacturing. Our safety was well
taken care of and we were provided with all the necessary and required safety gear to face any
enentuality in case of an emergency . Here on, I’d like to produce an insight to the technical aspects of
the factory.
There are mainly 3 divisions of the RWF , they are Wheel Shop, Axle Shop and the Assembly
station. The RWF produces ~1,50,000 wheels and ~48,000 axles of different guage lengths (narrow
gauge,broad gauge,etc.) for various purposes. Unlike the Europian countries where the wheels are
forged (suitable for high speeds) , the wheels required by the Indian Railways are casted (suitable to
sustain more loads) as due to the huge economy of India the Railways are the primary transport for
passengers as well as goods and also because casting is economical as compared to forging.

2. 13
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August, 2016 (Copyright 13/08/16 Abhigyan nath)



Wheel Shop:-
We were introduced to the cope and drag for the wheels,the UHPF(Ultra High Power Furnaces),
the sand used for the mould and were also shown how the massive cranes bring the molten metal in
huge laddles and pour them into the John Mohr pits, then they are made airtight and pressure in applied
so that the molten metal flows uniformly into the mould,the sprues are removed by using oxy-acetylene
flame, then the risers are used to put these freshly casted wheel onto the conveyor for further refining
processes (heat treatment, Primary Rotary Furnace). It takes 9 hrs for a wheel to come out of the
primary rotary furnace. The metal melts around 1700*c and the temperature is tried to be maintained
till a certain point. Then the wheel is put to priliminary surface finish processes. (Bombarding of the
curved surface with small cast metal balls at high speeds) as CNC machinig of these surfaces are not
recommended. Then the wheel is tested for internal and external ruptures,cracks by Ultrasonic and
Magna glow testings respectively. The core of the wheel has to maintain its softness whereas the outer
rim of the wheels has to be hardened ,this is achieved by Quenching of the wheel (sudden absolute
cooling). Then the wheel moves to the Brinell and Rockwell Hardness testing shop. These wheels are
also tested for Bending and elasticity.Then the final surface finish is given. The final checks are then
performed on the wheels by the employees, if they are not satisfactory then the whole wheel is sent for
melting and the whole process is repeated. If they hold good they are allowed to cool. That is how the
wheel shop functions. Generally the wheels are remade from the scrap metal received from various
parts of the country. The wheels are made out of cast steel.
Axle Shop:-
The Axle shop manufactures a variety of axles as requested by the Indian Railways and wheels
specific to each(TATA steel) axle are paired together. The axles are made out of fresh metal produced
directly by steel plants , they come into the RWF as blooms. These blooms are then treated upon by LPG
flames to cut these blooms into billets of the required sized, these happen under controlled
circumstances and under the supervision of trained engineers. Then then these billets are sent into a
secondary rotary furnace for melting and heat treatment, after 4 hrs the billets at ~1500*c come out of
the furnace and they are actually as soft as a sponge. Then these billets are fed into a hammer forge
where each jabber exerts a force of 8 tonnes on each blow to beat the billet into the shape of an axle,
these axles are inspected. They go through a screwing process for the fitting of wheels, a rough rolling to
get rid of most external rough surfaces, then CNC machining for the wheel seats, lubricants and anti-rust
fluid is sprayed and painted upon the axles, then there is the final Rolling which takes the precision and
accuracy upto ~0.5-0.05mm. Then there is a heat treatment and the axles are quenched for hardness.
Then these axles are left to cool under the atmosheric (natural) air. Then quality checks are performed ,
if it comes out satisfactory it is passed else it is rejected and sent back.

3. 13
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August, 2016 (Copyright 13/08/16 Abhigyan nath)




Assembly Station:-
For locomotive engines the wheels are not assembled with the axles as there are couplings
th0at need to be attached to the axles and accordingly each locomotive axle is given a larger or smaller
wheel seat depending on the requirements(as power needs to be generated by the engine). But for the
coaches and bogeys the wheels and axles are assembled together by means of pressure fittings, namely
interference fit, clearance fit and absolute fit. Interference fit is recommended as after this the wheel is
rigidly mounted on the axle. Hydraulic systems are used to apply these massive pressures. Reminding,
proper threading has been performed on both wheels and axles and sufficient corrosion resistance has
been imparted to both the products. By this time the manufactured wheels and axles are ready to be
put in service of the Indian Railways.
Overall it has been an overwhelming experience for all of us , to know that
such facilities exist in the vicinity of our surroundings in itself induces a sense of pride and joy. The
Indian Railways is the largest recruiter with over ~1.4 million employees and still growing far and wide.
The RWF is just a production unit among all the various factories under the Indian Railways. Fresh
graduates can serve the Indian Railways either by the RRB (Railway Recruitment Board) Entry or through
the ESE (Engineering Services Examinations) and join the workforce. Within the factory there is also a
Materials Testing lab and a Research and Development Lab. In the near future the Indian Railways is also
working towards a high speed rail project inspired from other developed nation. We are absolutely sure
that the Indian Railways will achieve this target in a short span of time.

-Report produced by
Abhigyan Nath
IEEE- #93595541
(B.E.)Mechanical Engineering ,
PES University,100 ft ring road,Banashankari 3
rd
stage,
Hosakerehalli,Bangalore-560085
Email- [email protected]
Contact- [phone]

4. 13
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August, 2016 (Copyright 13/08/16 Abhigyan nath)