Transport business are based on four basic pillar 'QDDS' of Quantity (Q) to transport, Distance (D) to transport, Duration (D) of transport and sort of Services (S) facilitated by transporter to their customers. In this topic, will discuss about the point Q which is reckoned as the most crucial point for any transportation mode. In India, we have four different mode of transportation to serve the nation inwardly i.e. Surface mode, Railway mode, Airways mode and Inland waterways mode. All of those have their different modal share among transport sector to carry out Passengers and different kind of Goods. In this context, we can definitely says that railway carries the highest tonnage than any other transporter in every financial year. Indian railways carries 1246 kind of goods in 365 type of stocks. Among them Open stocks and Jumbo stocks has highest utilisation index. Every stocks has different kind of characteristics and specifications in terms of weight carrying capacity. Before going to discuss technical & mathematical aspect of it, want to through some light on how quantity are correlated with distance and make GTKM, NTKM like productivity index. 

 

Tonnage Kilometres         

At first we should clear the concept of TKM or Tonnage Kilometers index using in railway statistics. What is TKM? TKM is a fundamental unit to express the mobility and loading capacity of a single unit on account of revenue earning work. In other language, how much quantity? For how much distance? lets break the confusion by illustrating this. In 24 hours span, 59 BOXN carried 4179 MT Coal for 300 Kilometers and a 42 BCN carried 2500 MT Food grains for 120 Kilometers. What will be the Gross and Net Kilometres earned by those stocks in 24 hours span? We all have a rooted perception about gross and net is, Inclusiveness means gross and Exclusiveness means net. What are need to exclude to get the net? A locomotive and Some stocks to creates a train. So when we exclude the weight of locomotive and tare weight of wagon, we will get net figure. As per the above mentioned example NTKM of 59 BOXN will be 4179*300=1253700 and of 42 BCN will be 2500*120=300000. This is how distance are correlated with quantity in transportation fields. 

 

Pay to Tare Ratio and Revenue earning

We have a transport company, we have some carriers to move out goods. Let, you placed a indent of some goods weighted 50 k.g but our carrier weighted 18 k.g and they can carry only 40 k.g. therefore, the Pay to Tare Ratio of that carrier will be 40k.g/18k.g = 2.2 or 11:5 means if there was 16 total proportion, 11% can be filled with goods against 5% tare load. If the difference between net weight and dead weight are in increasing nature, it meant to be economical growth of the organisation. The low tare load of railway wagons is significant not only to produces the possibility of carrying a higher payload but also increases the energy consumption per payload tonne hauled. One way to reduce the energy consumption per tonne payload is to reduce the tare load. One possibility of lowering the tare load is to reduce the number of components such as a bolster, sideframes, and axles. To take advantage of the lower tare mass, a new concept wagon was conceptualised as a wagon with maximum axle load and with enough load space to ensure a higher tonne gross load. More you can lower dead weight, the more you can carry goods. In IR, currently BOXNS is such a wagon which have the most effective pay to tare ratio with 4.2 or 21:5

 

Carrying Capacity              

Our railway system are in forth position in terms of freight movement. IR loaded 1400+ million tonne of goods in F.Y 21-22 including bulk, break bulk and non-bulk commodities, built light tare wagons, built HHP locos to drag and strengthen their routes to carry effective load. If we notice IR has 4 types of route in terms of carrying capacity. We saw there was a progressive revolution. BG route was started with maximum 22t. Axle load carrying capacity, also called as Excepted CC+6 route then it was extended by 0.4 and made up 22.4t. Axle route also called Universal CC+6 route. Then CC+8 or 22.09t. axle route comes into force. Most of the IR routes are now fitted with 22.09 axle loading capacity but several years ago IR upgraded their 1st 334 k.m long iron ore EXIM route BSPX to PRDP via JKPR into 25t. axle route. After this, almost all iron ore dominating routes of SER, SECR, ECoR and SWR became 25t. axle route. As a result india ranks 4th in iron ore exporting. In this context a question may be arise in mind that despite the highest loaded commodity why coal routes are not universally 25t. axle loading fitted? Probable answer may be given geographically as well as statistically. All soil region of the country are not tough enough as compared to Chottanagpur domain. When a 5800 to 5900t. loaded rake run through 75-80 k.m/hrs it lefts immense impact on soil and track and statistically IR has not enough 25t. axle stock for consequent 25t. coal loading. Thats why at present, 25t. axle loading is permissible only for iron ore in specified routes. Maximum how many tonnage of goods can be loaded in a wagon? This limitation varies on two factor, Carrying Capacity of indented wagon and Carrying Capacity of booked route to reach destination. Wagon CC is a constant index, where Route CC or Permissible Carrying Capacity (PCC) is a variable in accordance with 

A. Various route wise 

B. Various commodity wise 

C. Session wise. 

Whenever a consignment booked via more than one type of route i.e Expected CC+6, Universal CC+6, CC+8 and Iron ore route, the permissible weight will be as same as the most restrictive route. Why the commodity factor is discernible in times of wagon loading? IR has sets the commodity wise PCC variety, keeping in mind the significance of agriculture sector, industrial sector, Salt-Sugar like two essential consumable, Food grains and others:-

                 1) At the top, Raw materials for plants and Agricultural product had been patronised as Raw materials is a basic factor in making decisions on the establishment of building-material production plants, regardless of the scale of production and Agriculture can be important for developing countries in several ways, where food security is weak it can be a vital source of nutrition, it provides income for farmers and farm workers and thus revenues for rural areas, job opportunities in related areas such as processing and in some cases export revenue. 

2) At second, Sugar & Salt commodities that drove the world. For millenia, religion, commerce, war, health, and gold were tied to little white crystals. In the beginning animals wore paths, looking for salt licks, men followed, trails became roads, settlements grew beside them. Scarcity kept salt precious and as civilization spread, two became one of the world’s principal trading commodities. 

3) At third, Food grains. Healthy people are assets, they live longer, they should be more productive, and their existence may not be associated with misery and liability. Therefore, national development is incomplete without a healthy population, which accounts for national productivity. That's why healthy food grains that meets food preferences and dietary needs for an active and healthy life. 

4) Others commodity except above mentioned commodity head which IR used to carry has the least PCC ever. 

IR has also a provision to set PCC session wise. The PCC for carrying coal during monsoon period i.e. 1st July to 15th August when loaded on CC+8 route, shall be 1 tonne less than usual. 

 

Empty Weighment of rakes

For instance, in railways weight of loose bulk commodities are determined by deducting the designed tare weight of all wagons (without actually weighing them) from the gross weight of the rake. Railway assume the sum total of designed tare weight of wagons to be the actual tare weight of rake. The designed tare weight of wagons may not be remain same and there is high chance to increase during the course of various overhauling. That is why actual tare weight of rakes should be verify by weighing them in empty condition after a certain periods.

 

Last word

Now a days, overloading by violating PCC beyond tollerance limit is a common scenrrio over IR. Loads are getting originated unweighted under SWA (Sender's Weight Accepted) upto first available motion weighbridge and founded huge overweighted. As per commercial manual V-2 of IR, though there was a provision of collecting overloading charges, but it is not about revenue earnings at all. Railways have permitted the running of trains loaded with enhanced quantity without complying with the conditions laid down for protecting track and rolling stock. Even after permitting loading of wagons with enhanced quantity, the trend of overloading continued. Increased incidence of rail fractures, weld fractures and defects in

wagons and locomotives was seen. Such practice should be stopped.