RDSO Trials on Horsepower to Trailing Load Ratio

Information here is from studies published by the RDSO, with corrections and updates by Prakash Tendulkar and friends at Indian Railways. The data here are selected extracts from larger datasets published by RDSO.

Some trials were run by RDSO a few years ago (2000-2004?) to determine the feasibility of running freight trains other than container freights at speeds of 100km/h or higher. As part of this, they investigated the effect of increasing the power available to draw the rake. Below are some of the results from those studies

Impact of HP/TL ratios on transit times

Analysis of the effects of horsepower to trailing load ratio (HP/TL) was done through simulation studies on the Mughalsarai - Sonnagar section. These studies indicated that the correlation between the HP/TL ratio and transit time (free running time) is of the order of 0.98. However, this correlation was found to be valid only within a certain range, specifically, up to a value of 1.5 for the HP/TL ratio. Increasing this ratio beyond 1.5, especially on flat terrain, was not found to show any commensurate decrease in free running times.

Impact of HP/TL ratios on transit times
Motive Power Load HP/TL Transit Time (minutes)
1 WDG-2 57 loaded BOXN 0.661 171
2 WDG-2 57 loaded BOXN 0.985 150
1 WAG-7 57 loaded BOXN 1.048 147
2 WAG-7 57 loaded BOXN 1.576 132
1 WDG-2 57 empty BOXN 2.235 133
1 WAG-7 57 empty BOXN 3.524 130

Impact on hauling capacity

In Scenario 9a below, the gain from high-Speed BOXN/BTPN wagons with Mail/Express/Passenger halts reduced and schedules tightened was found to be about 9%. Further in Scenario 9b, it was found that double heading all BOXN/BTPN trains lead to a total gain of about 29%. As such, an incremental gain of almost 20% was obtained from the increase in HP/TL ratios. However, comparison of Scenario 2d (gain of 3% with high-speed BOXN) with Scenario 5 (gain of about 13% from double-headed high-speed BOXN/BTPN) shows an incremental gain of about 10% from higher HP/TL ratios. This leads to the conclusion that using a combination of measures can leverage benefits of higher HP/TL ratios, such as reduction of stoppages and tightening of Mail/Express/Passenger schedules.

Impact of HP/TL ratios on hauling capacity
Scenario BOXN speeds BTPN speeds Pass. Halts = 1min M/E/Raj. Halts = 1min Pass. schedule tightened M/E/Raj. schedule tightened Gain
1d All loaded freight 2 WAG-7 BOXN/BTPN=100 100 100 Y - - Y 33%
2d 100% high-speed BOXN 100 - - - - - 3%
5 High-speed freight, double-headed 100 100 - - - Y 13%
7 High-speed freight, double-headed 100 100 Y - - Y 18%
9a High-speed options 100 100 Y Y Y - 9%
9b High-speed freight, double-headed 100 100 Y Y Y Y 29%
(Only data for selected scenarios is shown.)

Further, on comparing Scenarios 7 (100km/h BOXN/BTPN rake double headed with 2 WAG-5 locos and passenger stops reduced to 1 minute, gain = 18%) and Scenario 1d (100km/h BOXN/BTPN rake, all freight double headed, passenger stops 1 minute, gain = 33%), it is seen that an incremental gain of almost 15% is obtained from increasing HP/TL ratios all across the board for freight trains as compared to increasing HP/TL ratios only for hi-speed BOXN/BTPN trains.