February 6, 2023 | Insights
Trends to Watch in Short-Haul Logistics: Electric Shunt Trucks
February 6, 2023 | Insights
Imagine a DC operation where you don’t have to deal with that familiar engine noise or its fumes; in fact, since your shunt truck has an electric motor in place of a combustion engine or transmission, you won’t have to worry about engine-related repairs or replacements. The powertrain is largely maintenance free. Because there are no fumes, your trucks won’t require emissions control equipment or time spent on diesel regeneration cycles. You don’t have to deal with variable diesel prices either; instead, you utilize the most efficient vehicle fuel available on the market today: electricity. And in the process, you save: some estimate their savings to be $20,000 to $90,000 per year for moderate to heavy use—all while keeping the power and agility of the trucks you’re used to.
What are electric shunt trucks?
Electric shunt trucks are not an entirely new concept. Orange EV, the first U.S. company to build and deploy 100% electric Class 8 heavy-duty trucks, for example, delivered their first terminal truck in 2015. For many, electrification is an inevitable transition toward clean, zero-emission alternatives. The development of electric vehicles had been fostered by growing support from governments, businesses, and the public for Environmental, Social, and Governance (ESG) initiatives. More and more stakeholders have bought into the idea that aside from achieving productivity gains or taking care of one’s bottom line, contributing to sustainability and public health is the right thing to do. Another important catalyst had been the need to comply with government regulations.
Government regulations for shunt trucks and non-road diesel engines
In the mid-1990s, about 47% of the total mobile source inventory of harmful PM2.5 (particulate matter less than 2.5 microns in diameter) and 25% of the NOx (nitrogen oxides) inventory were estimated to be from land-based non-road diesel engines such as those in forklifts and shunt trucks. In the U.S. in 2008, the EPA set standards for non-road diesel engines and fuel to meet the goal of the Clean Air Act, which was designed to significantly reduce the particulate matter and sulfur levels in fuel and, thus, increase public health benefits and facilitate the introduction of advanced emission-control technologies.
Cumulatively, a 2030 goal has been set for a 129,000 ton PM2.5 and 738,000 ton NOx annual reduction from emissions, which is projected to drive public health improvements including approximately 12,000 fewer premature mortalities, 15,000 fewer heart attacks, 1 million fewer lost days of work due to adults with respiratory symptoms, 5.9 million fewer days when adults have to restrict their activities due to respiratory symptoms, and almost 6,000 emergency room visits for asthma attacks in children.
To give engine manufacturers time to develop the required technologies to become compliant, the EPA regulations have been introduced in phases:
Table 1. EPA Tier Phases
|2001 to 2005
|Allowed federal authorities the power to issue and deny operating permits on regulated equipment
|Focused on limiting toxic gasses such as nitrogen oxides (NOx), carbon monoxide (CO), particulate matter (PM), and non-methane hydrocarbons (NMHC)
|Further limited emissions for engines; required highway engines to have advanced exhaust treatment systems to reduce harmful emissions
|Required the restructuring of engines to reduce emissions; significantly reduced NOx and PM emissions, while CO emissions limits remained the same from Tier 3; brought a new ultra-low sulfur diesel fuel
|All vehicles <8,500 gross vehicle weight
|All vehicles <10,000 gross vehicle weight; engines under 37kW
|Vehicles with 5-750 horsepower
|Engines from under 25 horsepower (hp) to above 750 horsepower; Engines used for heavy loads and made post-2017
Signed in 2004 and phased-in from 2008 to 2015, Tier 4 standards for nonroad diesel engines of all horsepower ratings were geared towards significantly reducing NOx and PM emissions, while keeping CO emissions limits as they had been in Tier 3.
Ultra-low sulfur diesel fuel: an imperfect solution
These standards also brought a new ultra-low sulfur diesel (ULSD) fuel, advanced engine technologies, and exhaust gas after-treatment systems utilized to reach the set emission targets. Notably, the addition of emissions equipment bumped the price of total equipment price by 1 to 3%; however, the EPA suggested that the efficiency savings more than make up for the additional costs of the equipment.
Another critical complaint was tank corrosion associated with the use of ULSD, especially when tankers transport both ethanol-based gasoline and ULSD. Microbes, specifically Acetobacter in diesel fuel, were thought to ingest trace amounts of ethanol, creating levels of acetic acid high enough to cause corrosion.
Shunt trucks and the EV age
Faced with increases in diesel prices, carbon emissions, and problems associated with ULSD and after-treatment systems, various stakeholders have become increasingly supportive of electric mobility programs and their related battery and charging station technology. Auto and truck manufacturers have shifted their efforts to producing electric vehicles. Industrial real-estate developers have also observed that there have been more installation requests for charging stations at DCs, which indicates a shift towards electrification by supply network companies.
To meet the demand for electric vehicles, manufacturers like Orange EV, AutoCar, Terberg, BYD, Renault, Volvo Penta, and Tevva have initiated and increased their production of all-electric shunt trucks in the past years. These terminal tractors or yard trucks do the same work of moving semi-trailers within the cargo yard, warehouse facility, or intermodal facility. They bear the same look: a single-person cab offset to the side of the engine, a rear door, and a short wheelbase. The big difference, of course, is in its source of power: the electric motor instead of the diesel and alternative fuel engines.
Table 2. Sample Electric Shunt Truck Models
|Gross Combination Weight Rating (GCWR)
|130,000 to 210,000 lbs
|72,000 lbs (5th wheel)
|Environmental Temperature to Operate
|30°F to 120°F
|-22°F to 122°F
|40°F to 140°F
Benefits of shunt truck EVs
Manufacturers and DCs see shunt truck electrification as highly viable because of their operational proximity to the home base, making it easier for the trucks to get back to their charging stations and be charged between shifts, work breaks, and other downtimes. Further, the higher braking frequency attributed to their constant starting and stopping in the yard allows for further energy regeneration. On the ground, drivers and operators are finding that they can bypass problems related to emissions systems that need to be installed on diesel-powered on-road shunt trucks. They’ve noted those systems had issues with excessive idling, and shunt trucks often idle 50% or more during a given work period.
Initially, many professionals wondered whether these electric yard trucks had the pull capacity and the battery ability to withstand shock load. Others are concerned about whether these trucks can operate in colder conditions. However, automakers have shown confidence in their trucks’ capacity to lift or pull (several manufacturers list their lift capacity near 50,000 to 80,000 lbs) and operate in frigid weather. With some EVs claiming their ability to operate at -22°F, automakers say that they are better than diesel because they start immediately and avoid the typical excessive winter idling.
EV shunt truck challenges and considerations
Possible unforeseen or extended downtimes related to charging represent some of the biggest logistics concerns with EVs. Yet, the technology currently allows for around 2 to 3.5 hours of fast charging, allowing the trucks to run for 10 to 24 hours. Battery technology also continues to improve.
As for charging facilities, a 2018 UPS and Greenbiz study showed that many fleet managers felt their facilities weren’t equipped enough to accommodate commercial charging needs. Accordingly, a number of electric shunt truck manufacturers have made it so that, for most logistics sites, the electric infrastructure that is utilized already exists–and the current circuit capacity of the DC is merely extended based on the desired charging speed, from standard to fast charging.
A more sustainable future for shunting operations
Are you moving towards the electrification of your DC operations’ truck fleet right now or in the near future? If you are looking to build a joint business case for EVs, NSSL can support you with your shift as we are able to work with any vehicle type. With a strong focus on sustainability and reducing our carbon footprint, NSSL is your partner on these sustainability initiatives. In the past, as we do now, we have worked continuously to improve our environmental performance across our value chain. And because we believe every move counts, we work to decrease the idle time and number of moves; meanwhile, reducing the average amount of emissions.
Aside from shunting services, see how NSSL’s yard management logistics could provide operational excellence to your facility. Plus, find more insights and tools to help uncover new opportunities within your operation.