What every transit maintenance manager should know
By Halsey King, SAE, NTEA, MSMBA
The Times, They Are A-Changin’
As we look to the future of transit systems, it’s essential to understand the rapid advancements in motive power technology. Many of us can recall the significant changes in motive power over the years, from the first cars we drove to the first airplanes in which we flew. Motive power has evolved from coal and wood-fired engines to steam engines, electric motors, propane, diesel, gasoline, and compressed natural gas (CNG). Each of these advancements has brought new challenges and opportunities.
In the 1970s and 1980s, we saw a shift towards CNG, and many of the technologies from that era are still in use today. It’s crucial to prepare for the changing transit fleet, as these changes will impact your work environment, crew, tools, and overall safety.
A Brief History of Electromotive Power
Electromotive platforms have been a cornerstone of transportation since the 1930s, with early applications in locomotives and submarines. These early trains were powered by diesel, gas, and propane, which drove generators to provide electric power for traction motors. This concept remains relevant today, albeit with more precise technology and smaller hardware.
The introduction of hybrid buses marked another significant change. Hybrids, which combine internal combustion engines with electric motors, have proven to be reliable and efficient. Along with other platforms, hybrids continue to play a vital role in moving people across the country.
The Rise of Battery Electric Buses (BEB)
The most notable recent advancement is the development of Battery Electric Buses (BEB). These buses eliminate the need for an engine and generator, relying solely on a set of batteries, known as the Energy Storage System (ESS), to power the motor. BEBs represent the future of transit, offering a cleaner and more efficient alternative to traditional buses.
Preparing for the Transition
To successfully transition to a BEB fleet, several key factors must be considered:
1. Charging Infrastructure: Establish a comprehensive charging plan with your local power supplier. This plan should account for current and future power needs as your BEB fleet grows.
2. Bus Selection: Purchase buses that meet your current and projected needs. As the population around your facility changes, your fleet requirements will also evolve.
3. Facility Upgrades: Update your shops and facilities to accommodate BEB fleets. This includes replacing old fuel pumps with new charging stations.
4. Staff Training: Ensure that your drivers and maintenance staff are well-trained in handling high-voltage systems. Mistakes with electricity can be fatal, so proper training is crucial.
5. Power Supply Management: Work closely with your Electric Power Supplier (EPS) to secure a reliable power source. Understand the variable utility rates and ensure backup power is available in case of storms, floods, or other unforeseen events.
Challenges and Considerations
Transitioning to a BEB fleet comes with its own set of challenges. The high voltage in these vehicles (700 volts or more) requires careful handling and strict safety protocols. Additionally, the industry may experience periods of slow growth, similar to what we saw with propane and CNG. However, the long-term outlook for electric buses remains positive.
As electric vehicles (EVs) become more prevalent in public transit, it’s crucial to prepare your transit system for the changes that come with an evolving EV fleet. Here are some key considerations and strategies to ensure a smooth transition.
Portable Energy Solutions
One of the first steps is to ensure you have access to portable energy solutions. The Electric Power System (EPS) can provide portable trucks equipped with Energy Storage Systems (ESS) or other means to address periods when a local bus is out of service. Having these portable units on hand, or ensuring your power supplier can provide them when needed, is a wise move. This flexibility can help maintain service continuity during unexpected downtimes.
Facility Layout and Traffic Management
The layout of your facility will need to adapt to accommodate EV charging stations. Traditional bus depots may require reconfiguration to optimize traffic flow and charging efficiency. Consider the following:
• Charging Station Placement: Depending on the type of charging system, the location of the plug can vary (front, back, side, top, or ground). This will influence how buses enter, navigate, and exit the facility.
• Traffic Rotation: Plan the yard layout to ensure smooth traffic flow. Determine the best routes for buses to enter, move through, and exit the yard, minimizing congestion and maximizing efficiency.
• Power Hardware and Routing: High-power EV hardware will be concentrated in specific areas, but power connections may be needed throughout the facility. Clearly mark these connections and ensure everyone is aware of their locations to avoid accidents.
Inductive Charging Areas
For those implementing inductive charging, special areas will be required. These systems allow buses to charge without the driver needing to leave the seat, enhancing efficiency. However, they may require more space to line up buses for charging. Ensure your facility can accommodate this setup.
Safety Measures
Safety is paramount when dealing with EVs and high-voltage systems. Implement the following safety measures:
• Fall Restraints: Many EV buses have batteries and equipment on the roof. Install fall restraint systems to prevent accidents when technicians are working on top of buses. Simple lanyards or more elaborate systems can be used, depending on your facility’s needs.
• OSHA Compliance: Larger transit systems often use wraparound bus maintenance platforms to enhance safety and efficiency. These platforms can help prevent falls and make maintenance tasks easier.
Maintenance and Training
Maintaining an EV fleet requires specialized training and equipment. Key areas to focus on include:
• High Voltage Qualification: Ensure your staff is trained to handle high-voltage systems safely. This includes understanding the differences in component maintenance and using the appropriate tools.
• Drive Motors and Electric Air Compressors: Familiarize your team with the unique aspects of EV drive motors and electric air compressors. While similar to traditional systems, they have distinct characteristics that require specific knowledge.
• System Diagnosis: Diagnostic procedures for EVs differ significantly from traditional powertrains. Invest in training to equip your staff with the skills needed to diagnose and repair EV systems effectively.
• Personal Protective Equipment (PPE): Proper PPE is essential when working with high-voltage systems. Ensure your team has access to and uses the correct protective gear to prevent accidents.
Continuous Improvement
As the EV landscape evolves, so too should your transit system. Stay informed about the latest advancements in EV technology and continuously update your training programs and facility layouts to keep pace with these changes. By proactively addressing these areas, you can ensure a smooth transition to an EV fleet and maintain efficient, safe, and reliable transit services.
In summary, preparing your transit system for a changing EV fleet involves a combination of strategic planning, facility adjustments, safety measures, and ongoing training. By addressing these areas, you can effectively manage the transition and continue to provide high-quality transit services to your community.
As transit systems transition to electric vehicles (EVs), it’s essential to understand that while many components will remain familiar, there are new elements and considerations to address. Here’s a comprehensive guide to preparing your transit system for an evolving EV fleet.
Conventional Maintenance
Despite the shift to electric propulsion, many conventional systems and components on your buses will remain the same. You’ll still deal with disc brakes, solid front axles, and possibly split rear axles. Some buses may feature the new Allison configuration, which resembles a traditional transmission, though most will not. Outside of the motor-powered unit, expect to maintain familiar components such as electric motors for windshield wipers, driver air ride seats, and wheelchair lifts. These elements will continue to require regular maintenance and attention.
Facility Layout and Charging Infrastructure
The layout of your facility will need to adapt to accommodate EV charging stations. Here are key considerations:
• Charging Port Locations: Buses may have charging ports at the front, side, or rear. Inductive charging systems may be located on the top or undercarriage. Knowing the location of these ports is crucial for planning station locations, yard circulation, and non-charging parking stalls.
• Auxiliary Charging Stations: Your shop will need auxiliary charging stations to charge buses after maintenance before they return to service. This is especially important for para-transit operations, where the same principles apply.
Energy Storage Systems (ESS)
The Energy Storage System (ESS), commonly known as the battery pack, is a critical component of EV buses. It provides the high voltage needed for vehicle propulsion and electrical accessories. The ESS includes batteries, controllers, and a high voltage distribution system. While the layout may vary between manufacturers, the fundamental components remain consistent.
Handling Heavy Batteries
EV bus batteries are heavy, often weighing around 2,500 pounds each. Removing and handling these batteries requires heavy equipment and trained staff. As battery technology advances, future batteries are expected to be smaller and more powerful, reducing weight and increasing efficiency.
Safety and Training
Safety is paramount when working with high-voltage systems. Ensure your staff is trained in high voltage qualification and understands the differences in component maintenance. Proper Personal Protective Equipment (PPE) is essential for safe operations.
Diagnostic Procedures
Diagnostic procedures for EVs differ significantly from traditional powertrains. Invest in training to equip your staff with the skills needed to diagnose and repair EV systems effectively. This includes understanding drive motors, electric air compressors, and other unique components.
Future Trends
The future of EV buses includes advancements in battery technology, aiming for smaller, more powerful batteries with greater range. As technology evolves, staying informed about these advancements will help you adapt your transit system accordingly.
Bus Manufacturers
The landscape of bus manufacturers has changed over the years. While there are fewer manufacturers today, companies like Gillig, New Flyer, RIDE, CCW, and others continue to produce electric buses. For smaller buses, manufacturers like Forest River, Diamond, Turtle Top, and Coach and Equipment are key players.
Understanding the New Technology
Access Services of Los Angeles will soon pilot its version of a battery electric paratransit bus that is equipped with solar panels. These buses come with a 400-volt battery, which, while not as powerful as a 700-volt system, is still dangerous if mishandled. The buses are equipped with standard SAE J-1772 48 amps, level 2 charging, regenerative braking, and liquid-cooled batteries. Although the components are in different locations, the tools and skills required to work on these buses remain largely the same.
Emphasizing Safety
Safety cannot be overstated when dealing with high-voltage systems. Even a small amount of electricity can be dangerous. For instance, at 0.1 amps, you might experience difficulty breathing and muscle contractions. By the time you reach 1 amp, the situation can become life-threatening. Therefore, only trained and qualified personnel should service the internals and components of these vehicles.
NFPA 70E training is essential, and proper lockout/tagout procedures must be followed. Ensure that personnel use the required PPE, including leather glove protectors, safety glasses, and long-sleeve natural fiber clothing.
Facility Layout and Charging Infrastructure
The layout of your facility will need to adapt to accommodate EV charging stations. Here are key considerations:
• Charging Port Locations: Buses may have charging ports at the front, side, or rear. Inductive charging systems may be located on the top or undercarriage. Knowing the location of these ports is crucial for planning station locations, yard circulation, and non-charging parking stalls.
• Auxiliary Charging Stations: Your shop will need auxiliary charging stations to charge buses after maintenance before they return to service. This is especially important for para-transit operations, where the same principles apply.
In Conclusion
As we delve deeper into the subject of preparing your transit system for a changing fleet, it’s essential to stay informed and adaptable. The future of transit lies in part with electric power, and by addressing the key areas of power supply, facility upgrades, bus selection, staff training, and safety, you can ensure a smooth transition to a BEB fleet.
By embracing these changes and preparing accordingly, you can position your transit system for success in the evolving landscape of motive power.
Halsey King, a member of the Society of Automotive Engineers [SAE], National Truck Equipment Association [NTEA] and the Mid Size Bus Manufacturers Association [MSBMA] is a bus fleet maintenance consultant with decades of fleet experience all over the world. U.S. clients include public and private transit and paratransit bus fleets, state DOTs and bus manufacturers. Halsey and his associates are members of several professional organizations, including SAE, ASTM, IEEE, and the American Public Transportation Association.