Visit to WAP at Yelehanka - Part 1
by Karthik M.V.
Yesterday Mr.Ravi, Mr."Poochi" Venkat from MAS & myself enjoyed some hard core railfanning for 10 long hours!
Thanks to our very own ADRM & IR officials, We got a guided tour of Wheel & Axle plant, KJM loco shed & footplating from KJM loco shed to SBC, which was an icing on the cake! Personally, the visit was a great learning experience for me too.
Here is my report:
In the morning around 1000 hrs. we went to the WAP at YNK, met the GM's sec'y, & he arranged for a JEE of mech dept to take us around the plant. The campus is really beautiful & very clean too. Even the sec'y room was well furnished, so just cannot imagine how luxurious will the GM's room be!
The JEE was technically well versed with all the concepts & processes. He told us that, India is the only country in the world having this type of modern plant outside the US! It seems the WAP do not produce wheels for passenger coaches. They produce only wheel sets of locos, BOXN, milk tanker & a few MG . He first took us to the Wheel plant. This a huge shed like building, where all the processes, from raw material to final product is carried out under one roof. It was surprising to note that the man power was very less. All the processes are fully automatic & computerised. During the 'tour' it was a thrill to see those red hot wheels & also the liquid with an orange glow! Here is a brief about wheel making process: All scrap metal (old wheel sets, tracks, etc.) are treated & sent to a melting tank. Here using 3 electrodes (3-phase) the metal is melted into liquid form at abt 11000amps & some 2000deg C. Then the liquid is sent to a kind of an underground pit. When the metal is at sufficient temp, the pit is closed with a lid having a type of pipe made of ceramic material. Then the mould box is placed over this pipe & with air pressure the metal is pumped into the mould. Like this, mould boxes keeping arriving on roller belts, & are filled with metal & then sent for further processing. The mould box is made of graphite & is in two halves. Bottom half has 2/3 of the wheel impression & the other half has 1/3. A great thing is that the moulding processes is so perfect that, the wheel surface is pucca & machining is done only for minor corrections. Using a CNC oxy-acetylene flame the axle hole in the wheel is made perfect. Then after several heating processes the final wheel is deposited in a godown.
After, this we went to the neighbhouring axle plant. Here also everthing is automised. Only manual part is wheels have to be fed into the assembly line. All the axles are of solid steel & are machined in CNC lathe to get the proper dimensions. Basically the extreme ends of all axles have lesser dia, where roller bearing sets are inserted in later by ICF/RCF. The parts of the axle where wheels or gear(incase of locos) has to be inserted is of larger dia. The axle hole dia of wheels is 1mm lesser than axle dia. Using a hydraulic machine a brute force of 3000kN is used to put the axle into the wheels. This type of fixing the wheels removes any welding process & also improves the rigidity of wheel & axle. As per JEE's words, till todate there has never been a case of wheels coming apart from the axle. The axle ends where roller bearings have to be inserted are covered with a plastic cap to avoid damage during transportation. After final qualtiy check the wheel sets are sent to the godown, from where they are loaded into BoxC rakes & sent for export or ICF/RCF/DLW/CLW .
So, after enriching our knowledge we came out of the plant around 1:15pm. As, we were all wearing a safety helmet, we thought it would be great to take some snaps & the JEE obliged us as well. But,no photography inside the plant. Later we bid good bye . I think, Mr.Ravi can add more technical details, as he is a Mechy :- )
Later, after having some delecious lunch at "Tamarind" CSDR, we headed towards KJM loco shed.