Efficient Friction Management and fuel technologies in Railways

Improving fuel economy, EV ecosystem, Role of Railways

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Introduction

The history of Indian Railways dates back to over 160 years ago when the first passenger train in India departed for Thane, about 34 kilometers from Bombay’s Bori Bunder station. 400 people traveled on 14 vehicles pulled by three steam engines Sahib, Sindh, and Sultan, that pulled the 14-carriage train. The Great Indian Peninsula Railway was entrusted with the responsibility of running the passenger route. A 1,676 mm (5 ft 6 in) wide gauge track was used to build this train.

In India, there are several types of railway track systems used for passenger and goods transportation. The main types of railway track systems in India are Broad gauge (BG), Meter gauge (MG), Narrow gauge (NG), and Dual Gauge (DG). The major distinctions between these track systems are first, the distance between the tracks, and second the Speed, capacity, and Cost.

The distance between the tracks varies as:

Broad Gauge > Meter Gauge > Narrow Gauge

Broad gauge tracks can accommodate higher speeds compared to meter gauge and Narrow Gauge tracks. This means that trains on broad gauge tracks can travel faster and cover longer distances in a shorter time as compared to the other track types.

Broad gauge tracks have a higher capacity than meter gauge and Narrow Gauge tracks. This means that these can accommodate more passengers and freight, making them more efficient for transporting large volumes of goods and people. The cost of constructing and maintaining different types of railway track systems varies. Broad gauge tracks are generally more expensive to construct and maintain compared to meter gauge and Narrow Gauge tracks.

Overall, the choice of railway track system depends on factors such as the terrain, passenger, and freight traffic, and cost-effectiveness. In India, Broad Gauge tracks are the most commonly used due to their high capacity and ability to accommodate faster speed. The implementation of high-speed railways in India is in its early phases and vast studies are being conducted for the effective implementation of the system based on the specifics of our nation. Maintaining the traction required for efficient operation of trains at high speeds requires the net minimum frictional coefficient to be maintained at the wheel-rail interface across the desired range of axle loads and target speeds of train operation. With the increase in speed, wheels of the train tend to lift-off, effectively reducing the interface friction at the wheel-rail contact.

Railways’ huge efficiency advantage comes primarily from the technology of steel wheels rolling on steel rails. As steel is very hard, the shape of a train’s wheel does not change under load, and the rail-wheel contact area always remains minimal and very small, resulting in very low friction force to come into play. Further, since trains can be very long, typically 250-300 meters to a few kilometers (in case of freight) and can carry hundreds/thousands of passengers and several thousand tons of freight, the air drag force per unit of freight/passenger reduces drastically. All these factors result in huge efficiency gains in favor of Railways.

Railway is considered to  efficient mode of transportation in India and elsewhere. As per the National Transport Development Policy Committee (NTDPC) Report of 2010, Railway consumes 75 to 90% less energy for freight and 5 to 21 % less energy for passenger traffic compared to road-based transport. Rail is over 8 to 10 times more efficient than road for passenger and freight transport depending on loads, operating conditions and technologies deployed. In simpler  words, a  liter of fuel can move 4 -10 units of passenger/freight by train compared to 1 unit by road vehicle. 

Fuel efficiency leads to environmental benefits. Efficiency simply defined is “output per unit of input” Output of any railway system. It is commonly measured in terms of Gross Ton Km (GTKM) or Net Ton Km (NTKM) or Passenger Km (PKM) moved over the railway system in a given time frame. Key inputs to a railway system are in the form of fixed infrastructure like track, bridges, signals, traction power supply and distribution network, stations, rolling stock like locomotives, coaches and wagons, manpower like station staff, crew, infrastructure and rolling stock maintainers etc, fuel and materials. 

Railway systems are characterized by high fixed costs (track, bridges,etc) and low variable costs (fuel, consumables etc) and so typically for increasing efficiency the fundamental need is to increase throughout in the railway system.In this subsequent content, we will discuss the knitty-gritties of  efficient friction management and fuel technologies in Railways. Also, the different ways of improving fuel economy, EV ecosystem and the role of railways into all this.

Efficient Friction Management

Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Efficient friction management aims to increase traction or grip and modify lubrication to consequently affect the behavior of passing wheels. These include reduced noise, improved fuel efficiency, protection of rail assets, or extended asset life. 

Challenge

The continuous contact between the wheel and the rail surface is less than one square centimeter. Failing to manage the friction between the wheel and the rail reduces the life of wheel and rail that consequently increases the risk of derailment due to flange climb. 

Friction at the wheel-rail interfaces in railway operations plays a significant role in maintaining sufficient traction, for running trains with safety and to have the ability to accelerate, decelerate or brake the train at specified locations on the railway track. 

Maintaining the traction required for efficient operation of trains at high speeds requires a net minimum frictional coefficient to be maintained at the wheel-rail interface, across the desired range of axle loads and target speeds of train operation. With the increase in speed, wheels of the train tend to lift-off, effectively reducing the interface friction at the wheel-rail contact.

Rail Lubrication Scenario in India & Worldwide

In India, Rail & Flange (R&F) lubricators have been in use for long. These lubricators have a small tank of 1 to 2-liter capacity with a nozzle that oozes out grease as and when a wheel flange presses its actuator. These are not maintenance-free and have mostly gone out of use. The most commonly used method had been the manual application of graphite grease at a weekly or any other predetermined frequency on the gauge face of the outer rail in curves.

Inspired by the benefits reported by world railway systems, IR decided to give a trial to gauge face lubrication by installing Wayside lubricators from tried and tested brands. RDSO took the responsibility of zeroing upon the manufacturer based on Techno economic bids. 

Canadian Pacific Railway (CPR) has spent the past 5 years implementing an optimized “100% effective gauge face lubrication” strategy on 3250 km of their 24,000 km network to control friction at the interface between the wheel flange / rail gauge face.

In Britain, lubrication has traditionally been provided as part of the infrastructure. Mechanical and hydraulic lubricators were placed in curves at the point where wheels commenced flanging contact. 

Benefits 

With an Efficient Friction Management mechanism in place, IR can achieve some of the below mentioned benefits.

  • Reduced asset whole life cost 
  • Reduced track worker risk profile
  • Reduced track asset risk profile
  • Ensured Higher Safety and Smooth Ride
  • Lesser Noise
  • Reduced maintenance cost and high efficiency
  • Reduced centrifugal forces at radius curves
  • Lesser Derailment Risk at tight curves
  • Reduced Lateral Stress at flange contact
  • Reduced carbon footprint

Use of Friction Modifiers and Lubricant solutions

Friction modification is done through the use of lubrication solutions. It reduces the Rail / Wheel Wear (Gauge Face, Flange), rolling contact fatigue (RCF) development, Flange Noise,  Derailment Potential (Wheel Climb),  Lateral Forces (indirect), corrugations, vehicle hunting. At the same time it improves fuel efficiency and ride quality.

  • Wheel-Rail Interface Lubrication: Innovative lubrication systems are deployed to reduce friction at the wheel-rail interface. This not only extends the lifespan of these components but also reduces the energy required to overcome rolling resistance.
  • Condition-Based Maintenance: Using sensors and IoT (Internet of Things) technologies, railways can now monitor the condition of tracks and rolling stock in real-time, optimizing maintenance schedules to ensure minimal friction and wear.
  • Aerodynamic Design: Reducing air resistance through better design of train bodies also contributes to friction management, albeit indirectly, by improving overall energy efficiency.

Fuel Technology in Railways

Under the flagship programs of the Government, “Advanced Chemistry Cell (ACC) Batteries” and “National Hydrogen Mission”, to cut down on the Green House Gases (GHGs) emission under Paris Climate Agreement 2015 and “Mission Net Zero Carbon Emission Railway” by 2030, Indian Railways is set to run trains on hydrogen fuel-based technology.

Going Electric

Today, 94% of the Indian rail network stands electrified. Indian Railways has become the country’s largest consumer of electricity, and the impact of this shift towards electrification on the country’s energy independence is significant. By 2030, the total energy requirement of the Railways is expected to increase to 8,200 MW, or 8. 2 GW. Out of this, 700 MW or 8.5% will be sourced from Coal Plants due to existing agreements. Remaining 91.5% is planned to be sourced from renewable energy sources like Hydro Power Plant, Solar Energy. 

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Focus on Non Renewable Source of Energy

We need to focus more on  distinct renewable energy sources like Hydro Power Plant, Solar Energy to be converted into mechanical energy through solar plants along with wind Energy, which  is also a major source of renewable energy. These will contribute to the Net Zero Carbon Emission goal of Indian Railway as well and making the world a better place eventually.

Indian Railways, in its ambitious move towards sustainability, has significantly ramped up its renewable energy capacity, commissioning about 211 MW of solar plants and around 103 MW of wind power plants as of October 2023. With the expansion of routes and trains every year, the power demand for metro corporations is also increasing at massive speed, which is expected to put tremendous pressure on the country’s urban power supply.

With an aim to increase the renewable energy resources’ contribution in Indian Railways and urban metro system various initiatives have been taken by theIndian  Railways. For Indian Railways, which has set the target of the 500MW energy from the solar rooftop, 96.84 MW of solar plants have been installed, and 16 stations have been declared as green railway stations across zones.

We have upgraded our fuel technologies into the 3rd generation namely from Steam Engines to Diesel Engines,Diesel to finally Electricengines. Now the world is moving towards the cleanest type of fuels like Hydrogen, etc. It is already in the testing phase and very soon we will witness a prototype deployed by the  Indian Railways for the same.

Hydrogen Fuel-Based Technology

Hydrogen trains use hydrogen fuel cells instead of diesel engines. These cells produce electricity by combining hydrogen and oxygen, which generates electricity which is further used to power the train’s motors. 

As per PIB press release dated 3rd Feb 2023, Minister of Railways, Communications and Electronic & Information Technology, Shri Ashwini Vaishnaw informed Rajya Sabha that Indian Railways (IR) has envisaged running 35 Hydrogen trains under the  “Hydrogen for Heritage” initiative.

IR has also awarded a pilot project for retro fitment of Hydrogen Fuel cell on existing Diesel Electric Multiple Unit (DEMU) rake along with ground infrastructure at the cost of ₹ 111.83 crores which is planned to hit the tracks on Jind –Sonipat section of the Northern Railway.

The use of Hydrogen as fuel provides larger benefits in the direction of green transportation technology to support zero carbon emission goals as a clean energy source. It has no adverse environmental impact during operations as the byproducts are simply heat and water. Unlike bio-fuel or hydropower, hydrogen doesn’t require large areas of land to be produced. 

Commercial operations of hydrogen-powered trains would take India into an exclusive club of railway systems operating emission-free locomotives. Currently, only Germany operates commercial hydrogen-powered trains, while the same technology remains in the testing phase in the US, the UK, France, and Japan.

Advancements in Fuel Technologies: 

  • Hybrid and Fully Electric Trains: The shift towards hybrid and fully electric trains represents a significant leap in reducing the reliance on fossil fuels. Electric trains offer vastly improved efficiency and lower emissions as compared to their diesel counterparts.
  • Alternative Fuels: Research into alternative fuels, such as bio-fuels and hydrogen fuel cells, provides promising avenues for reducing the carbon footprint of non-electrified sections of the railway network.
  • Regenerative Braking Systems: These systems capture energy typically lost during braking and convert it into electrical energy, which can be either used to power the train or fed back into the grid, further improving the overall fuel economy.

Consumption of Fuel/Energy

In Railways, mileage is not measured in kmpl but liters per 1000 GTKM (gross tonnage hauled per km) or specific fuel consumption.  Average figure ranges from 4 – 4.5 liters per 1000 GTKM for a passenger train and for goods train it is 2.25 to 2.75 liters per 1000 GTKM.

A tarin consumes roughly  15 units per Gross tonne km (GTKM) for passenger trains like Rajdhani etc and 10 units per gtkm for goods trains. 

A WAP-4 locomotive has 6 DC traction motors and 3 auxiliary motors and it consumes around 840–1080 KW in an hour Or 6500 KW-8500 KW in 8 hours. Whereas a 3 Phase locomotives like WAG-9, WAG-9H, WAP-7 have regenerative braking system that saves the consumption of electricity up to 20% . These locomotives consume electricity around 720 KW -840 KW per hour 5760 KW -6720 KW in 8 hours.

The cost of running a diesel locomotive for 1 kilometer in Indian Railways varies depending on a number of factors, including the type of locomotive, the weight of the train, and the distance traveled. However, the average cost is around ₹280 per kilometer.

Improving Fuel Economy

Fuel Economy is measured in terms of SFC (specific fuel consumption). It is the amount of fuel consumed per unit of work done. In Indian Railways SFC is measured both for the engine and the train to assess the performance of the engine as well as the total formation of the train. It is obvious that a lower  SFC is the indication of a better  Fuel Economy.

CRIS has already developed a fuel management system for Indian Railways. However there is a huge scope for improvement in the fuel economy.

  • Aerodynamic Enhancements and Lightweight Materials: By investing in research to make trains more aerodynamic and using lightweight materials for construction, railways can significantly reduce energy consumption.
  • Smart Routing and Scheduling: Advanced algorithms and AI can optimize routes and schedules, reducing idle times and ensuring trains run at speeds that maximize fuel efficiency.

Role of Railways in the EV Ecosystem

In recent years, the development of electric vehicle (EV) infrastructure and efforts to achieve more sustainable transportation systems have increased. The enhanced utilization of EVs will require fast charging systems, which will overload utility power grids and require high-cost additional installations and equipments. 

There are 123 redeveloped railway stations in India where NITI Aayog has recommended the installation of EV charging facilities immediately, rather than waiting until 2030. Because of their unique role in the transportation industry, railway stations make an ideal location for installing public charging stations for electric vehicles.

Railway stations can provide a secure and accessible charging infrastructure for city residents, in addition to existing government initiatives. Many Indian Institutes of Technology (IITs) researchers have developed new charging technology for electric vehicles, which is half the price of the current onboard charger technology. Two and four-wheeled electric vehicles can benefit greatly from these.

However, a significant amount of regenerative braking energy (RBE) is available in electric railway systems (ERSs), which needs to be properly stored and accommodated. The integration of ERSs and EV charging stations (EVCS) at strategic points, such as parking areas close to ERS stations or rail freight intermodal terminals where EVs are parked most hours of the day, can be a promising solution to save RBE in the dedicated internal EV batteries.

Budget 2024-25 announcement

Union finance minister Nirmala Sitharaman while presenting the Interim Budget for 2024-25 announced to set up three major railway corridor programmes for energy. The interim budget allocation has bettered that record and assigned Rs 2. 55 trillion to the Indian Railways. It is aimed at addressing congestion and reducing cost of logistics. It is obviously going to to boost economic growth. The announcement is the government’s forward looking financial roadmap focusing on green energy. 

The three corridors are poised to significantly boost economic growth and streamline logistics for industries, thereby enhancing overall efficiency. A slew of proposals announced in the budget for startups and electric vehicle ecosystem would also  accelerate the sector and encourage entrepreneurship. 

Dedicated freight corridors (DFC), with appropriate technology, enables the Indian Railways to regain its market share of freight transport. It also creates additional capacity and assures efficient, reliable, safe, and cheaper options for mobility to customers.

There are many ongoing projects to charge EVs by transferring RBE from ERSs to EVCSs, taking advantage of a combined power management scheme based on stationary hybrid energy storage systems (HESSs) integrated with railway power flow controllers (RPFCs). 

EV Charging Stations

Government of India (Gol) has identified promotion of Electric Vehicles (EVs) as a major step towards decarbonization of the transportation sector and reduceing demand for petroleum products, and has taken a slew of initiatives to encourage large scale EV adoption. 

Further to promote an accessible and robust network of EV charging infrastructure, the Ministry of Power (MoP)- Gol had issued guidelines on charging infrastructure. The guidelines issued by the MoP has recommended setting up of at least one public EV charging station in a 3X3 km grid in a city and one charging station at every 25 km on both sides of highways or roads.

IR intends to replace its existing fleet of (owned / hired / leased) Internal Combustion Engine (ICE) cars used by IR employees with EVs across the country. Battery Swapping facility is also going to enhance user friendly activities at EV charging stations.   

Affordable and accessible charging infrastructure is a prime concern today. IR has started to identify and allocate parking spaces in its office complexes and stations to be used for EV charging facilities. Zonal Railways has also explored the possibility of setting up Battery Swapping Stations (BSS) for E-Vehicles.

Integration of Infra & Services

  • Charging Infrastructure: Railways can play a pivotal role in developing the EV charging infrastructure. Integration of charging stations at or near railway stations can facilitate the accessibility of the charging points making easy charging for electric vehicles available to all, thus encouraging its use.
  • Last-Mile Connectivity: Electric trains coupled with EVs for last-mile connectivity can create a seamless &eco-friendly transportation network. This synergy can significantly reduce urban congestion and pollution levels.
  • Energy Management: Railways can leverage their large, often continuous, demand for electricity to foster renewable energy investments, such as solar or wind power installations along tracks or on unused land. This green energy can power electric trains and EV charging stations, closing the loop on sustainability.

Conclusion

Since 1850s when the first train ran in India and royal families sponsored its expansion to the present-day envious network and 13523 trains running daily, railways has connected India like nothing else. In order to achieve net zero emission and zero carbon footprint, IR has to make continuous sustainable improvements. Technical advancement is the key contributor. Research and Developments need to take place more frequently. Efficient friction management is prime concern for high speed trains and need to be properly addressed. Improvement in fuel economy, fuel technology is urgent requirement. Growing EV Ecosystem demands robust software system and world class infrastructure. All stakeholders including department respective officials, government, policymakers need to gear up for the upcoming challenges.  

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