AFVi’s CEO, Annalloyd Thomasson, sat down recently with Steve Duricky, Global Platform Manager at Parker Hannifin, to talk about the current status of hydrogen vehicle adoption in heavy-duty fleets, potential engineering challenges for their fuel systems, and why many organizations are viewing natural gas as an important bridge to this technology.
Their discussion highlighted a growing industry reality: many heavy-duty and off-road applications require alternative technologies that can deliver diesel-like performance while reducing emissions.
How Hydrogen Affects Heavy-Duty Applications
According to Duricky, hydrogen is gaining attention because some heavy-duty applications remain difficult for other fuel sources, such as electrification. Large construction equipment, Class 8 trucks, and off-road vehicles often require long operating hours, high horsepower, and rapid refueling, which battery technology still struggles to provide.
Hydrogen vehicles can often be refueled at speeds comparable to diesel. This presents a significant advantage for remote construction sites and fleet operations while avoiding costly downtime.
Duricky also emphasized that hydrogen offers two types of propulsion systems—hydrogen internal combustion engines (ICEs) and hydrogen fuel cell systems—which give fleets greater flexibility in operating environments.
The Engineering Challenges Behind Hydrogen Systems
While hydrogen offers promising opportunities, it can introduce engineering challenges distinct from those of traditional diesel systems.
One of the biggest involves its molecular size. As Duricky explained, hydrogen is the smallest molecule on Earth, and can permeate materials more easily than other fuels. This means that sealing technologies are critical to system reliability and safety, including the prevention of hydrogen embrittlement (more on that below).
Storage pressure is another factor. Because hydrogen systems operate at pressures up to 10,000 PSI, they require specialized storage tanks, valves, tubing, and regulators.
Temperature considerations also affect system design. Components in hydrogen delivery systems may need to operate reliably in environments as cold as -40 degrees Celsius.
What Is Hydrogen Embrittlement?
Hydrogen embrittlement occurs when hydrogen penetrates certain metals, potentially resulting in cracking, fatigue, and premature component failure.
As Duricky explained, embrittlement prevention involves:
- Selecting the appropriate materials
- Using higher-grade stainless steel
- A quality machining process
- Reduced leak paths in system design
- The ongoing monitoring of pressure, temperature, and leakage
Hydrogen ICE vs. Fuel Cell Systems
While having a choice between hydrogen internal combustion engines and hydrogen fuel cells offers fleets more flexibility, it’s important for managers to understand which fuel system type is best suited to a given environment.
Fuel cells generally require extremely clean hydrogen—often referred to as “five nines,” or 99.999% pure hydrogen. Because of those purity requirements, fuel cells are currently more common in on-road transportation environments where contaminants can be better controlled.
Heavy-duty off-road environments create additional challenges. Dust, dirt, and airborne contaminants found on construction sites can make fuel cell durability more difficult in current applications. Duricky suggested that hydrogen ICE systems may serve as a more practical near-term solution for heavy equipment until fuel cell technology matures further.
Natural Gas as a Bridge to Hydrogen
A major theme throughout the discussion was the relationship between natural gas and hydrogen.
Duricky described compressed natural gas (CNG) systems as a practical transition pathway because fleets and technicians with experience in them already understand how to safely manage high-pressure gaseous fuel systems.
Today, natural gas vehicles operate successfully across:
- Refuse
- Transit
- Commercial trucking
- Municipal fleets
Many of the engineering principles used in CNG systems also apply to hydrogen systems, including:
- High-pressure storage
- Pressure regulation
- Leak prevention
- Safety monitoring
Although hydrogen fuel systems are not identical to those using natural gas, organizations that are familiar with CNG possess foundational knowledge about gaseous fuels that can benefit their operations.
The Importance of Workforce Readiness
Duricky noted the need for appropriate technician training to support hydrogen fuel system inspections.
Transitioning from diesel to gaseous fuels requires engineers and technicians to learn about entirely new operating environments, including high-pressure gas behavior, hydrogen safety procedures, and emerging standards—including CSA HGV 3.1 and the ISO 19880 series, which create consistency and improve safety for broader commercialization.
Heavy Equipment Represents a Massive Opportunity
One of the most compelling takeaways was when Duricky outlined the scale of heavy-duty fuel consumption.
With millions of Class 8 trucks operating across North America—and many traveling roughly 100,000 miles annually—the heavy-duty transportation sector consumes enormous amounts of diesel fuel every year.
That creates a challenge and an opportunity.
While hydrogen infrastructure is still developing, the industry continues to move forward through pilot programs, prototype development, and collaboration among major manufacturers. Companies such as Toyota, Daimler, Volvo, and Cummins continue to invest heavily in hydrogen technologies and fuel system development.
Preparing for the Hydrogen Transition
Duricky’s final recommendation about hydrogen adoption was a practical one: start small.
Rather than attempting an immediate full-scale transition, fleets can begin by introducing a single alternative fuel vehicle, learning how gaseous fuel systems operate, and gradually building familiarity with the infrastructure, maintenance practices, and engineering considerations.
We encourage you to watch the full Powering Progress interview above to learn more about hydrogen fuel systems, heavy-duty transportation, and workforce readiness. For questions about its material, please contact Parker Hannifin or AFVi directly.
