The new Milwaukee Streetcar system has been in the planning, design and construction phases for over 10 years and on November 2, 2018, operations with a combined overhead contact system and streetcar battery power commenced ushering in a new era of growth for the City of Milwaukee. Many challenges in the design and construction of the overhead contact line and power system were encountered during this time period including budgetary constraints, multiple pole location changes, underground obstacles, low clearance bridges, alignment changes, utility conflicts, and changing vehicle requirements. The line was originally designed for pantograph operation but soon adapted for pole/pantograph current collection and then changed back to pantograph only current collection during the final design. The original design consisted of underground feeder cables to supplement a 4/0 contact wire but eventually not utilized due to budgetary constraints. Instead, a larger 350 kcmil contact wire was used with no paralleling feeder cables. The added weight of a 350 kcmil wire with wind, ice and low temperatures created high forces in the overhead contact system (OCS) leading to challenges in pole and foundation design where compliance to the National Electrical Safety Code (NESC) was required. The OCS style originally proposed and finally constructed used an inclined pendulum suspension (IPS) system that was constant tensioned with rotating springs deemed by the installing contractor superior to balance weights. The pendulum system was chosen as it is simple, lightweight, less visually obtrusive, and more economical than other suspension systems such as stitch and steady arm that are being used on other streetcar or light rail systems. IPS has provided Milwaukee with an excellent operating overhead contact system. Buildings along the route that were not historic structures were utilized where possible for span wire attachment but in many locations long bracket arms up to 40 feet long had to be used requiring special designs to keep the size of the pipes standard with the rest of the system. Challenges arose at low bridge underpasses where the contact wire had to be below required code height and special precautions had to be undertaken. Other areas such as the St. Paul Lift Bridge proved challenging as well where special electrically interlocked OCS devices were initially designed to de-energize the overhead wires and is further discussed with the reasoning for their use. This paper outlines the phases of design, the changes to the design that occurred over time, the challenges encountered to the OCS design, the method of design, and the final disposition of the design for construction. It further outlines the construction of the system and problems encountered with poles, foundations, bracket arms, traction power substations, contact wire, feeder cables, and winter conditions affecting the integrity of these structures and how some of these problems were solved.

Rail (passenger and freight) industry has been under pressure to tackle climate change, local and noise emissions. The current available powertrain technologies to reach the reduced greenhouse (GHG) and zero local emissions demands are electric (fed from the power grid), battery and fuel cell. However, the associated infrastructure costs (electrical equipments and the required overhead catenary infrastructure) have limited the electric option to heavy loaded corridors. Battery electric powered rail vehicles could be another potential option, but their system recharging requirements might significantly limit the system’s availability, thus, impacting the rail vehicle’s on-the-job performance. The recent breakthrough of fuel cell technology in the heavy duty road industry (mainly transit buses), allied with its operational flexibility and environmental performance has opened the way for this groundbreaking technology in the rail industry. Fuel cells generate electricity onboard, using hydrogen or hydrogen rich hydrocarbon fuels. Electricity is, then, stored in batteries or fed directly into a rail vehicle’s high voltage propulsion system. From an operational perspective, fuel cell powered rail vehicles might replace diesel ones in a one-to-one relationship, with the same range and running times, and a more efficient and less noisy powertrain. Moreover, the on-site refilling station is the only additional infrastructure element required, compared to diesel rail vehicle baselines. In short, fuel cell technology might offer a long term local zero emission alternative, fast refuelling (like diesel), flexibility, with self-electrification, integration with a renewable energy source and a quiet operation. Given their outstanding operational and environmental features, several rail market niches might be addressed by the fuel cell technology: i) light rail and trams in urban environments; ii) commuter and regional trains operating on non electrified tracks; iii) shunt or switch locomotives in rail yards (generally located on central portions of large cities or at the crossroads of major rail distribution hubs); iv) underground mining locomotives, and v) line haul locomotives. Since 2002, there has been an intense activity in the global development of fuel cell technology for the rail industry for both passenger and freight markets. This work is supposed to present, based on the compilation of information from a multitude of acknowledged sources, a review of fuel cell rail technology, followed by an overview of fuel cell rail experiences and feasibility studies, highlighting their main outcomes, as well as fuel cell technology potential to offer lower operational costs (fuel and maintenance) and improved performance for the rail industry.

A 2MW Battery Power System (BPS) was installed and tested in a traction power substation on the Orange Line of the Washington Metropolitan Area Transit Authority (WMATA), as a demonstration project. Measurement data were obtained under normal revenue service conditions. In addition, the same installation was tested as an emergency power source to move trains to desired destinations when the traction power system was under a simulated blackout situation. The results were analyzed to assess the ability of the BPS installation to achieve energy saving, peak power reduction, train voltage support and emergency power provision. This paper describes the findings from this demonstration project and the follow-on efforts in WMATA.

Diesel locomotives in heavy haul operations are good candidates to adopt energy storage systems (ESSs). This paper modelled a battery ESS and a flywheel ESS for heavy haul locomotives. Three heavy haul trains with different traction plans (diesel, diesel-flywheel, and diesel-battery) were compared. The diesel, flywheel, and battery locomotives have traction powers of 3100 kW, 2000 kW, and 3100 kW respectively. Available energy from the flywheel and battery ESSs are 500 kWh and 5000 kWh respectively. The simulated railway is about 300 km long while the trains are about 10,000 tonnes each. Traction performance and fuel consumption were compared. The results show that, compared with the diesel train, the diesel-flywheel and diesel-battery trains were 13.26% and 9.20% slower in speed respectively. However, they decreased their fuel consumptions by 12.40% and 20.65% respectively.

As railroads and local industries served by rail seek to reduce emissions and improve fuel efficiency, new technologies are being developed to serve this market. Contrary to the minimal competitive options available over the last several decades, new companies are now emerging with a variety of locomotive designs aimed at low emissions and low horsepower solutions. Some technologies involve alternative fuels (e.g. natural gas, bio-diesel, battery power, etc.), while others incorporate very low horsepower diesel engines (400hp–1000hp) in order to meet the Tier 4 regulations set by the Environmental Protection Agency (EPA). Yet another option available to railroads and local industries is the mobile railcar mover. Typically used within railroad yard limits or on industry tracks, yard and industrial switchers and mobile railcar movers travel short distances, but must be capable of moving large loads. Subject to high forces when moving cars, these technologies must be both resilient (requiring minimal maintenance) and safe (not subject to derailment or loss of control). As the current market for yard and industrial switchers continues to expand, both railroads and local industries served by rail are placing greater emphases on the environmental and economic benefits of the emerging technologies. This paper aims to analyze the current yard and industrial switcher market and draw conclusions based on emissions data and lifecycle costs. Industrial switchers are compared with yard switchers and mobile railcar movers. Although industrial switchers are more limited in horsepower and operational versatility than yard switchers, many of the daily operations between the two are similar. Mobile railcar movers (e.g. Trackmobile ® and Rail King ® ) offer lower initial costs as well as the versatility of both on-track and off-track movement. However, they may require additional maintenance and offer reduced tractive effort compared to locomotive technologies. As the demands on railroad yard and industry operations grow increasingly complex due to environmental regulations and economic demands, these new technologies have the potential to increase competition in the marketplace and offer improved engineering solutions. By developing a hierarchy of key requirements of yard or industry switchers, this paper provides a framework for identifying the best options available to a railroad or local industries. The scope of this paper will include a review of all options available, but will place a greater emphasis on technologies that are commercially available for wide distribution. By sampling and analyzing the current industrial market, much insight can be gained into daily operational requirements and challenges faced by this sector of the industry.

The interest of this work is to develop a control strategy to most effectively manage the power split between the energy storage system (ESS) and the diesel generator of a hybrid locomotive. The overall goal is to minimize fuel consumption of the diesel engine, while maximizing battery life of the onboard ESS. This problem proves to be complex due to the conflicting cost functions of fuel economy and battery state-of-health (SOH) [1] . In other words, during a typical drive cycle, fuel consumption is minimized by placing high loads upon the battery while minimizing negative effects on SOH requires more specific loading characteristics of the ESS for the same drive cycle. This work highlights the development of several power split control strategies for effective power management of a hybrid locomotive. The progression from a strict rule-based (RB) control strategy to an equivalent consumption minimization strategy (ECMS) is realized through simulation. Likewise, the advantage of Model Predictive Control (FLC) is also shown in simulation.

Hardware-in-the-Loop (HIL) testing allows for scaled to full-scale evaluation of components without constructing full-scale vehicle prototypes. HIL is also a rapid means of performance evaluation of difficult to model components, in real-time simulation with up to full-scale components providing their own response in place of a model. HIL also provides a working tool for control algorithm refinements prior to full system integration. In hybrid and electric locomotive applications this is particularly important while choosing the battery chemistry and sizing the energy storage system. Energy storage HIL testing permits optimal sizing of battery power and energy density along with management algorithm tuning. In general, HIL provides insight into optimal locomotive powertrain design. After the development of full EV and HEV locomotive models, battery component models were replaced with real-time interfaces to lead carbon and lithium cobalt batteries, which validated the battery models and helped tune vehicle controllers for direct application onto the vehicle platform.

One of the limiting factors in on-board bearing health monitoring systems is the life of the batteries used to power the system. Thus, any device that can extend the life of the battery, or entirely replace it, is a notable improvement on any currently available systems. Existing on-board monitoring systems, not optimized for low power, are designed to run on approximately 300 mW of power. Current bearing health monitoring systems have proven effective with as few as one reading every four minutes. The environment under which railroad bearings operate is a harsh one, making most forms of energy harvesting very hard to implement. Terfenol-D is a novel and sustainable solution for this problem due to its durable characteristics and strong magnetostriction. A fixture is designed using multiple magnets of ranging magnetization to properly characterize energy harvesting using Terfenol-D. The maximum available power observed during these experiments is about 77 mW under ideal conditions. The generated power is sufficient to run low-power bearing health monitoring systems.

Often, available power from an in-vehicle energy storage system is governed by thermal limitations. Modeling of battery pack thermal response is crucial to managing its cooling system energy consumption and estimating available charge/discharge power for future locomotive tractive and regenerative effort. Active cooling through forced air flow was simulated using computer-aided design of the battery pack and its enclosure. Module scaled (series string of 54 12V batteries) testing and modeling of both air flow and temperature distribution was performed and validated for sealed lead acid carbon batteries. A controller area network and data logger collected temperature data from 218 sensors placed throughout a battery pack module during electrical loading for both switcher and over-the-road cycles while under various environmental thermal loadings. A blower on-off control algorithm was optimized to minimize energy consumption and implemented based on temperature array statistics.

Dual-mode propulsion in the form of electro-diesel and battery-electric locomotives is an established concept. Locomotives using these technologies have been in service for many years to provide a ‘last-mile’ capability for freight trains and traction capability when electric power is not available due to system failure or intentionally during engineering work on the infrastructure. In recent times, dual-mode propulsion has extended the range of commuter trains with the introduction of electro-diesel locomotives that operate with third-rail or OHL electric power, or with diesel prime mover. In similar fashion, the range of high speed trains, capable of speeds of 110 mph or greater, can be extended beyond the OHL by adopting dual-mode propulsion. There are three circumstances where dual-mode propulsion of high speed trains is appropriate. The first case is where it is desired to extend high speed rail service now beyond the existing OHL territory in an interim stage while OHL equipment is installed on the route. The second case involves the extension of high speed rail service over an existing route where it not feasible to install OHL equipment. A typical example of the second case is where most of the operation is over an electrified line and the extension is a relatively small proportion of the total trip, possibly involving running over a line that also carries freight trains. The third case is the commencement of high speed rail service on an established line that is not electrified while the line is electrified progressively or completely new electrified line is being constructed. The Paper describes the conceptual design of a dual-mode high speed train that has the capability of operating in electric mode up to 186 mph and in diesel mode up to 110 mph. The train follows contemporary European high speed EMU practice for the electric mode aspect, with the driving cars replaced by driving power tenders (mobile traction power houses). The power tenders input electrical power to the EMU train at the direct current link in the propulsion system. Hotel and auxiliary power is provided by diesel generators mounted underfloor on two EMU cars. For changeover to all-electric propulsion, the power tenders are replaced by driving trailers, which increases the seating capacity of the train. The diesel generator sets are retained in the all-electric mode to provide hotel and auxiliary power and limited input traction power for get-u-home capability in the event of failure of the OHL system.

Significant technical, regulatory and media attention has recently been given to the use of electrical storage batteries onboard a line-haul (long-distance) locomotive or “energy storage tender” (coupled adjacent to a locomotive) as a means of improving railroad fuel efficiency and reducing freight locomotive exhaust emissions. The extent to which electrical energy stored onboard could supplement or replace diesel generated power has yet to be quantified or proven. There are significant technical design, maintainability, logistical and safety challenges to making this technology commonplace, especially for over-the-road (line-haul) freight trains. The use of electrical batteries to provide some amount of point-source fuel- and/or emissions-free locomotive power is not a new concept . Recent claims that onboard storage of locomotive propulsion energy is “new locomotive technology” are unfounded. The world’s first all-battery-powered locomotive was built in 1838 only 34 years after the world’s first steam locomotive operated. A total of 126 identifiable locomotives using onboard batteries to store propulsion energy have been built and operated to some extent in the United States (US) since 1920 . Almost all were low-power switching locomotives and none are currently in revenue freight service. Two high-horsepower line-haul experimental engineering test locomotives with an experimental battery design and regenerative dynamic braking have been built (in 2004 and 2007) but very little revenue service testing has occurred. This paper reviews propulsion battery-equipped locomotives over the past 95 years in the US, and discusses future options and possibilities including the technical and logistical challenges to such propulsion. Capturing dynamic braking energy (developed by locomotive traction motors during deceleration or downhill operation) could be a source of onboard battery recharging, but will require significant additional locomotive control system development work to achieve practicality. New battery technologies are being developed but none are yet practical for large-scale locomotive applications. Retrofitting of large amounts of onboard battery storage on existing (or even future) diesel-electric locomotives will be limited by onboard space constraints. The development and use of energy storage “tenders” will bring complications to locomotive and train operations to make effective use (if commercialized) practical and safe. This paper is also intended to provide technical background and clarity for various regulatory agencies regarding battery energy storage technologies for future locomotive propulsion.

This paper analyzes alternatives to carbon-based fuels, including ‘clean’ electric locomotive technology. Electrification of the North American railway network leaves many questions to be researched, such as: sufficient power capacity, ‘clean’ sources, distribution costs, infrastructure costs, logistics issues, legislative barriers, and resulting changes to business practises. A comprehensive review of incentives, logistics, and barriers was done to shed some light on emerging research needs to fill knowledge gaps in time to sustain industry competitiveness, and to meet the demands of a more sustainable future for North American freight, commuter, and tourism rail. Given prohibitively high costs and logistics of rail electrification, North American researchers have started focusing on ultra-capacitors and batteries. Previous research suggests that a hybrid capacitor/battery equipped locomotive would work, all within the existing envelope of locomotive chassis, and with much lower infrastructure costs. The transition in NA would be faster, at a much lower cost, including high speed passenger rail. However, no one has yet done the necessary research to verify this hypothesis.

As the desire to implement more electronic devices such as measuring or tracking systems on freight cars grows, having a source of power to rely on becomes an issue. An innovative and practical solution to keep batteries charged is presented. Placed on the car axle, the system uses the rotation of the wheelset as input motion. Friction wheels roll on the outside of the car axle, transferring the power to a generator through a set of gears. Designed to be easily implemented, the system can be installed or removed conveniently and quickly. The first laboratory tests showed that the system is capable of producing more than 100 Watts of power at a simulated 55 mph. A speed of only 20 mph is necessary to generate voltages high enough to charge a 12-Volt battery. A second series of tests proves that connecting the generator differently (in a “Y” configuration) improves the output voltages by about 70%, generating three times more power and requiring only 10mph to reach the voltage necessary for charging a common lead-acid battery.

Since its introduction, consumer GPS has made the tracking of critical items in the transportation chain more popular. Shipment of items via rail car is one link in the chain that serves to benefit from GPS technology. This paper discusses a wireless communications system suitable for tracking rail cars. In particular, the power source selection and system testing are described. The system was limited to one device and one power source, a battery. Findings show that the lithium battery selected will power the device for one to three years, depending on transmission activity. Recommended areas of additional research include: battery recharging techniques, effects of connecting sensors to the device, and investigating other communications devices as they become available.

A new type of battery-dominant hybrid technology has been developed for the rail industry. Switcher locomotive service is characterized by highly variable power output use. This variability in demand is exploited to allow the use of a significantly smaller, fuel efficient, Tier 2 certified, low maintenance engine and generator combination to supply energy to the traction motors and to the application-engineered battery pack. In the last three years, a demonstrator vehicle, the Green Goat®, has been designed, tested, constructed and put into field trials for 18 months in various locations and types of service, with impressive (performance and operational) results. The design, concept, field trials results, as well as applications of the technology to other types of service, are discussed.

Recent increases in fueling costs have created new interest in energy storage technologies for transportation applications. Railroad locomotives often have high peak-to-average demand for power, which leads to poor fuel efficiency from diesel prime movers, or arcing and pitting of overhead cantenary. One approach to this problem has been the development of diesel-battery hybrid locomotives. A large bank of lead-acid batteries provides peak instantaneous power, while a constant speed, high-efficiency diesel-electric generator set provides average power to the battery bank. This arrangement has proven practical in the Green Goat and other hybrids, although sizing of the generator set for a particular application, such as switching a railyard, becomes crucial. In addition, battery wear must be accurately predicted for peak performance, and the battery bank itself must be replaced after a few thousand cycles, increasing cost and creating a lead disposal hazard. Advances in capacitor design have created a new family of devices, known as super- or ultracapacitors. These devices have a mass-energy density which approaches lead-acid batteries, but with dramatically lower internal resistance and potentially limitless cycle life. However, the volumetric-energy density is much lower than batteries, thwarting a direct application in a practically sized rail vehicle. In this paper, a multi-stage drive is proposed, which takes advantage of the best properties of each energy storage device — capacitor, lead-acid battery, and diesel prime mover. The capacitor provides high peak instantaneous power, absorbing the cyclic nature of the locomotive’s power demands. The battery bank acts as a buffer stage, with fewer full discharge cycles and longer life. The diesel prime mover provides long-term sustaining power for the system. In electric railway applications, adding an ultracapacitor stage reduces peak current through the wire-pantograph interface, reducing wear and improving lifetime of the entire system. By increasing the size of the ultracapacitor stage to practical limits, a traction system may be constructed which reduces or eliminates the need for the cantenary/third-rail supply and interface, substantially reducing the cost of of electrified rail transportation.

The Office of Research and Development of the Federal Railroad Administration (FRA) is sponsoring a revenue service demonstration of Advanced Train Systems to demonstrate new technologies for improving safety and efficiency in freight train operations. The project, which commenced in 1999, is part of the Rolling Stock Program Element in FRA’s Five-Year Strategic Plan for Railroad Research, Development and Demonstrations. The demonstration system, referred to as the On-Board Monitoring and Control System (OBMCS), features an integrated package of sensors and actuators for monitoring and controlling mechanical components on freight trains. The OBMCS includes sensors to monitor bearings, wheels, brakes and trucks and actuators (referred to as advanced components) for remotely controlling hand brakes, angle cocks, cut levers and a cushion unit lockout system to eliminate slack. The demonstration, scheduled to commence in 2005, will feature a locomotive equipped with an EMD FIRE computer system and five freight cars equipped with the OBMCS and a New York Air Brake ECP brake system. The cars will also be equipped with Sharma & Associates tri-couplers, which automatically couple the cars, the pneumatic line and the ECP brake power cable. An open system architecture based on Controller Area Network (CAN) technology provides the framework for integration and control of the advanced components. The CAN bus network is also employed to monitor bearing temperatures and the status of brake piston travel sensors. A communication protocol based on a subset of CANopen Draft Standard DS401 V2.1 [CiADS401] has been developed to facilitate integration of sensors and actuators into the OBMCS. Science Applications International Corporation and Wilcoxon Research developed the sensor and supervision platform to integrate the advanced components. The OBMCS is powered by a battery, which is recharged by a generator bearing developed by the Timken Company. Intra-train communication and control from the locomotive is over an 802.11b wireless LAN. The FIRE computer in the locomotive receives status information from the systems on each car and transmits commands to the cars to operate the advanced components. Hot bearing, derailed wheel and truck hunting events are immediately relayed to the locomotive engineer. The OBMCS is also equipped with a IXRTT cellular radio to transmit results to a central database and website. A GPS receiver provides time and location information necessary to track a car. On board sensing of mechanical defects enables car owners to track defects and pro actively schedule maintenance at an economical time and location.