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Adding battery locomotives to traditional diesel locomotives to form a hybrid consist has the potential to reduce fuel consumption and emissions in freight rail operations. This paper provides route-based estimates of diesel (hpd/ton) and battery (hpb/ton) power requirements and diesel (gal/ton) and battery (hpbhr/ton) energy requirements for hybrid consists. Given a route-specific power profile, the power split between the battery pack and the diesel engine is optimized to minimize fuel consumption by running the diesel engine at maximum efficiency during the entire route. Simulations for 200-mile round trips between Chicago and Harrisburg show that the diesel power is maximum in low-gradient regions at 1.05 (hpd/ton) and battery power is maximum in hilly regions at 2 (hpb/ton) for discharge and 6.5 (hpb/ton) for charge. Maximum fuel efficiency gains of approximately 60% are seen in the mountains, where 2.09 (hpbhr/ton) of battery energy is needed. Minimum fuel economy gains are observed in flat regions, with 20% fuel consumption reduction. With battery current and voltage limits, the battery pack size increases, and fuel savings decrease. [ABSTRACT FROM AUTHOR]

The individual drive of the axles of a vehicle produces a reduction of the axle adhesion, implicitly reducing the total traction force of the vehicle. The paper proposes eliminating load transfer effects by using an algorithm to redistribute the traction effort between the tractive axles equipped with electric traction motors. A case study is presented, using the balancing of the electric traction torque for an electric locomotive, using the load transfer effects compensation. The conclusions can be used to maximise the traction of all types of vehicles, such as trailers, hybrid tractors, large harvesters, and Diesel-electric locomotives. [ABSTRACT FROM AUTHOR]

Excessive crosstie wear and abrasion and ballast wear and fouling are fundamental problems contributing to inadequate railroad track performance. This adversely affects the attainment and long-term maintenance of desired track geometric requirements. The magnitudes and distribution of the stresses at the crosstie-ballast (CT-B) interface must be known to determine the stress distribution on and within the ballast. However, the track design recommendations to determine these pressures, which are largely based on a methodology from the 1980s, are currently valid for modern-day railroad applications for multiple reasons discussed in this study. This study analyzed CT-B interfacial pressure data measured on an active freight mainline in Mascot, Tennessee. Dynamic contact pressures at the CT-B interface were measured using hydraulic earth pressure cells for various wheel loads and train speeds. The test train was a Federal Railroad Administration (FRA) test train consisting of a diesel electric locomotive, a test car that had different wheel loads based on the deployable axle load, and an inspection car. Although the maximum train speed was limited to 64 km=h, this research found that speed variation has a minimal effect on the CT-B interfacial pressures. From the measured data, a Gaussian stress distribution equation is proposed to determine longitudinal pressure distribution transmitted to the CT-B interface for static conditions. In addition, the stress distribution along the length of a crosstie was investigated via laboratory experimentation using a half-length crosstie. As a result of the experimentation, a dimensionless trilinear approximation was developed to estimate the stress distribution along the length of the crosstie. In general, this research recommends that the longitudinal and lateral stress distributions be considered together to design a better railroad track. [ABSTRACT FROM AUTHOR]

Hydrogen electric locomotives are receiving growing attention and progressing towards net zero. This letter discusses the improvement of traditional diesel-electric locomotives to use hydrogen and reduce energy demand. An internal combustion engine featuring direct injection and jet ignition of the hydrogen is proposed. The four-strokes, 12 L, V12 engine achieves peak power of 750 kW and peak efficiency above 46%. The propulsion system may be further optimized by adopting battery energy storage to buffer the operation of the engine and provide extra power when accelerating. This way, the engine may be further optimized to work over a narrower range of speeds and loads and be made smaller to provide reduced power. • Conversion of diesel locomotives to hydrogen is straightforward. • Use of a larger traction battery help with energy recovery. • It also helps using a smaller engine to work more efficiently. • Fuel cell alternative has efficiency advantage, but weight, volume, power density, and TRL disadvantages. [ABSTRACT FROM AUTHOR]

In recent years, the number of long-distance trains running on non-electrified lines has been increasing in Poland. Unfortunately, trains running on non-electrified lines, unlike those running on the hook of electric locomotives, are very often canceled, especially in the winter. In this research, the analysis of which lines had the most frequent cancellations of trains in 2021 and the reasons for these cancellations were analyzed. The results show that the most common cause of train cancellations was the lack of an efficient locomotive at the starting station. Most often, accessibility problems concern Czech series 754 diesel locomotives. The numbers of canceled trains in February 2021 and 2022 were also compared. The comparison showed that although the situation is far from ideal, it has improved significantly. [ABSTRACT FROM AUTHOR]

Individuals and institutions seeking to reduce travel-related carbon dioxide (CO2) emissions by changing travel modes need information on the amount of CO2 that can be saved by rail travel rather than air travel. This study uses flight emissions data from the International Civil Aviation Organization (ICAO) to estimate average per-passenger CO2 emissions saved by using rail travel between selected city pairs in the northeastern U.S. Trend lines are developed from the ICAO data for different aircraft types to facilitate comparison with CO2 emissions from rail travel. Separate rail emission factors are calculated for portions of Amtrak's system operating electric and diesel locomotives. An adjustment factor is estimated to account for longer rail distances than flight distances. Results show rail travel has generally lower CO2 emissions than air travel, with substantially lower emissions for electrified segments of the Amtrak system. At flight distances of over 700 miles, air travel using single-aisle jets can have lower per-passenger CO2 emissions compared to diesel-powered rail travel, accounting for the longer distances by rail. Implications: Savings in per-passenger CO2 emissions using rail rather than air travel in the northeastern U.S. Travel by rail in the northeastern U.S. results in lower CO2 emissions compared to travel by air between the same city pairs using existing airline and passenger rail infrastructure. Savings are higher for cities connected by electrified rail. [ABSTRACT FROM AUTHOR]

Abstract This paper presents a hypothetical conversion of a conventional heavy haul diesel-electric locomotive to its hybrid counterpart by incorporating a battery energy storage system. Starting from the basic parameters of a 1.6 MW diesel-electric locomotive currently found in the national railway company locomotive fleet, the quasi-static model of the locomotive is derived and validated. The conventional locomotive model is then converted to its hybrid counterpart by adding a battery energy storage system in parallel to the generator and equipping it with an adequate optimized energy management control strategy. The hybrid locomotive powertrain components are also appropriately re-sized in order to meet comparable traction force and power performance. Both the conventional and hybridized locomotive models are then used for the purpose of comparative analysis of main vehicle characteristics for the mountainous railway route driving scenario, which includes realistic slope and speed limitations. The obtained simulation results are used to gain insights about the possible advantages of the proposed conversion/drivetrain hybridization in terms of feasible reduction of fuel consumption and related CO 2 emissions, while also considering additional hybridization costs and return-of-investment period. Highlights • Backward-looking models of diesel-electric and hybrid locomotive are developed. • Battery is properly sized according to the braking energy potential. • Optimized energy management strategy has been proposed. • Hybrid locomotive can achieve fuel cost savings up to 16.5%. • Hybridization investment costs would be compensated three times. [ABSTRACT FROM AUTHOR]

The article discusses the importance of Locomotive speed and throttle settings in modelling sound levels from diesel trains. Topics include the requirement for noise mitigation was based on an increase in sound level from an existing scenario to a future scenario; train movements around stations, at low speeds or changes in locomotive technology are considered; and figures showing the Sound Level are also presented.

The diesel -- electrical locomotives are used from Romanian freight operators to run trains where electrical locomotives can't run. At Romanian Railways, one of diesel locomotives is 2100 HP Sulzer diesel -- electrical locomotives. [ABSTRACT FROM AUTHOR]

The paper considers a novel approach to heavy-haul of railway freight by means of combined operation of conventional diesel-electric and battery-electric locomotives either in single or joint (tandem) operation. A backward-looking quasi-static model of a battery-electric locomotive is proposed, based on the undercarriage of a decommissioned conventional diesel-electric locomotive equipped with a sufficiently-sized battery energy storage system. In order to facilitate power flow control from the battery-electric locomotive and to avoid deep battery discharges a suitable control rule is introduced aimed at modulating the driver power (throttle Notch) command in order to maintain the battery state-of-charge above the safe lower limit during discharging. The effectiveness of the proposed approach has been verified by means of simulations for the considered mountainous railway route driving scenario, including realistic railway track slope and speed limitations. The results show that between 22% and 30% fuel cost savings may be achieved, along with reduced emissions of exhaust gases by using the proposed battery-electric locomotive in combination (tandem) with the conventional diesel-electric one. • Simulation models of diesel-electric and battery-electric locomotive are presented. • Energy storage system for battery-electric locomotive is sized and parameterized. • Driving mission-related battery over-discharge is prevented by means of control. • Different tandem locomotive configurations have been proposed and validated. • Depending on configuration, between 19% and 30% of fuel savings may be achieved. [ABSTRACT FROM AUTHOR]