Watch: Wabtec’s Evolution Series Tier 4 Marks a Milestone
The nearly 1,200 units delivered so far have traveled more than 500 million miles of track—almost the distance between the Earth and Jupiter (569 million miles). Wabtec’s Tier 4s in operation today are approaching a combined 10,000 years of running time, according to the manufacturer.
GE Transportation (acquired by Wabtec in February 2019) began producing Evolution Series engines in 2003 to meet the EPA’s Tier 2 locomotive emission standards (see chart below and scroll down to watch video). By 2015, it had taken the technology even further, when the government agency required manufacturers of locomotive diesel engines to lower PM (particulate matter) 70% and NOx 76%, compared to Tier 3 standards.
TIER 4 EVOLUTION
(Chart and Photograph Courtesy of Wabtec, which acquired GE Transportation in 2019)
1998: EPA enacts first locomotive emissions standards (40 CFR Part 92)
2000-2005: Tier 0-Tier 2 emissions standards go into effect
2008: EPA defines Tier 3 and Tier 4 locomotive standards (40 FR Part 1033 enacted)
2010: Wabtec invested an additional $250 million into the development of its Tier 4-compliant technology—above its investment in its Tier 2-Tier 3 technology.
2014: “With lower-than-expected customer demand, the Tier 4 program reached a crossroad,” according to Wabtec. “We doubled down our efforts and prepared for full production by 2015.”
2015: EPA Tier 4 emission standard goes into effect. For Wabtec, orders came in for more than 600 units that delivered 70% decrease in emissions (compared to Tier 3 models), an advanced cooling system, and integration with digital solutions and remote monitoring and diagnostics.
2019: “Nine out of 10 Tier 4 locomotives in operations are from Wabtec,” with more than 100 million miles of track traveled and more than 2,500 years of combined locomotive run time.
July 2025: 10th anniversary of the Evolution Series Tier 4.
GE Transportation leveraged other GE business units to develop elements of the new engine, including power assembly, Exhaust Gas Recirculation (EGR), common rail fuel system, and turbocharger. In April 2015, it completed the first production test of its Evolution Series Tier 4 engine, and in July 2015 delivered the first production locomotive model to BNSF. Today, that Class I railroad has more than 350 locomotives that are Tier 4-compliant and roughly 65% of its fleet is Tier 3 or better.
Reduced Emissions and Operational Costs
The 432,000-pound, six-axle Evolution Series Tier 4 locomotive delivers 4,500 hp and can reach a maximum speed of 75 mph pulling thousands of tons of freight, according to Wabtec.
It offers:
- Variable speed auxiliaries. “Six panels and auxiliary inverters/motors eliminate the need for an auxiliary alternator, contractors and cycle skippers, and allow for increased fuel efficiency and reliability.”
- A two-stage charged air system featuring heat exchangers that “allows for 50% more heat rejection and a 25% capacity increase.”
- An increased platform length (+16 inches) and weight (+8,000 pounds).
- Base engine improvements, including “larger bearing size, longer induction hardened crankshaft, top feed fuel injectors, and simplified double-walled high-pressure fuel lines.”
- Engine Control Unit (ECU) and power supply with “50% more sensors and a separate power supply” to offer improved reliability, durability, performance and diagnostics.
- Two-stage turbocharging, which is said to allow for a higher compression ratio, fuel efficiency, and reduced thermal stress.
- EGR, which “meets Tier 4 Oxides of Nitrogen (NOx) standards.”
- An engine mainframe with a “larger casting (+8 inches) and increased weight (+7,000 pounds) allow[ing] for larger bearings and crank with increased cylinder pressure capability for better reliability and performance.”
Wabtec in 2019 celebrated the delivery of its 1,000th Evolution Series Tier 4 unit to CN.
“This achievement underscores [GE’s] bold decision in 2013 to develop a Tier 4 locomotive,” Wabtec CEO Rafael Santana said at that time; Santana served as President and CEO of GE Transportation before taking over Wabtec leadership. “Delivering 1,000 locomotives in less than five years proves it was the right locomotive at the right time to meet market needs.”
The Evolution Series Tier 4 unit saved railroad customers more than $1.5 billion in urea infrastructure and operational costs, Wabtec said in 2019. When combined with Wabtec’s digital solutions, like Trip Optimizer, the added functionality enabled the locomotive to realize 3%-17% savings on fuel costs and further emission reductions, it noted.
‘Innovation With Purpose’
“In 2008, the EPA defined the rules for Tier 4 emission standards, which made it extremely challenging from a technology evolution standpoint,” Rogerio Mendonca, President, Freight Equipment at Wabtec, told Railway Age earlier this month. “Many [manufacturers] went with what they called the aftertreatment strategy with urea. But that meant extra equipment, complex refilling, etc. So, Wabtec [GE] made a decision, and probably not a very easy one because it would require an extensive redesign of the engine. We adopted Exhaust Gas Recirculation technology that avoids all the extra equipment, extra fluids, etc.”
The company’s objective, he said, was not only to meet EPA’s standards, but also to “innovate with purpose,” focusing on efficiency, reliability and economics for customers.
Today’s Wabtec Tier 4 engines can run on biodiesel and renewable diesel fuels—the manufacturer has achieved B20/R100 across all its major engine platforms—as well as liquified natural gas. Wabtec is also preparing its Tier 4 engine to burn hydrogen.
“The Tier 4 is a great platform for today, and it’s a great platform for whatever comes in the future, in terms of internal combustion fuels,” Mendonca summed up. “This is the platform that will evolve.”
