Rebuilds RuleWritten by David Humphrey, Ph.D, Senior Data Scientist, Railinc Corp.
RAILWAY AGE, MAY 2023 ISSUE: Railinc’s analysis of the North American locomotive fleet reveals that the size of the total fleet decreased slightly in 2022.
New for this year’s report, the age of locomotives is based on the rebuilt year in the Umler® equipment registry, if the data is present. Otherwise, it is based on the original built year. This better reflects the presence of rebuilt locomotives in the fleet.
Detailed analysis reveals the following trends:
At the end of 2022, the locomotive fleet totaled 37,704, down 284 units (–0.8%) from 2021. That is up from the approximately –1.0% year-over-year decline in 2021. Rebuilding programs continue, but new locomotives are still rare.
The average and median ages of locomotives in the North American fleet continue to increase. The average age increased 0.9 years in 2022, and the median age was up 0.8 years.
High-horsepower AC locomotives with six axles are driving changes in fleet demographics. Most new additions to the fleet since the mid-1990s have been six-axle locomotives with a horsepower rating of 4,000 or higher. Locomotives with alternating current traction motors (AC units), which perform well at hauling heavy loads, account for most new additions to the fleet in the past decade.
Locomotives with the highest fuel capacity—more than 4,500 gallons—make up the largest percent of the fleet.
The long-term trend of new locomotives being added to the North American fleet paused in 2018, when the locomotive fleet decreased by three units and that decline continued in 2022. Last year, the locomotive fleet decreased by 284 units to 37,704 units, for a growth rate of –0.8%, up from the previous year’s growth rate of –1.0% (see Figure 1).
Most new locomotives in the report are recently rebuilt units rather than brand-new locomotives (see Figure 2).
Historically, the average age of the fleet and the number of locomotives added to the fleet mirror the economic environment. When the economy is strong, as in the mid-1990s and mid-2000s—and there are more railcars in service—the average age is lower and the fleet tends to grow. During periods of recession, fewer new locomotives join the fleet. The decrease in 2022 reflects both the lasting economic impacts of the COVID-19 pandemic and the excess supply of locomotives due to industry utilization improvements surrounding PSR (Precision Scheduled Railroading).
As new locomotives join the fleet each year, larger railroads move older units to less-demanding roles, sell them to regional and short line railroads, or make them available to be rebuilt
A locomotive has a long service life and can be used in a variety of ways over that time. It can make long hauls during its first decades of service. Then, it can work on regional and short line railroads in middle age. Finally, it can perform lighter-duty service—such as moving railcars in a yard—at 60 or 70 years old.
DC Holds Largest Share as AC Growth Continues
DC locomotives make up 62% of the North American fleet. The share of AC locomotives has increased 10% since 2012 as more AC units join the fleet (see Figure 3).
Although DC locomotives continue to make up nearly two-thirds of the North American fleet, AC locomotives have dominated among additions in the past 10 years. Based on updated data referring to the rebuilt dates, only 35 DC units were added in the past two years. And, in the past six years, most new locomotives were AC units.
Locomotives with a horsepower rating of 4,000 or higher continue to make up most of the North American locomotive fleet. These locomotives comprised 56% of the fleet in 2022 (see Figure 4).
Locomotives between 2,000 and 3,999 horsepower comprised 32% in 2022, down from 38% in 2012.
Of the locomotives built or rebuilt in the past five years, virtually all have a horsepower rating of 4,000 or higher. The fleet does continue to add lower-horsepower locomotives, though at generally decreasing rates. These lower-horsepower additions to the fleet are made up of rebuilt locomotives and new units used as switcher locomotives.
Locomotives with a horsepower rating of 4,000 or higher dominate among AC locomotives, which tend to be newer. There are close to two-thirds more DC locomotives in the North American fleet than AC units. However, DC units are more evenly distributed by horsepower rating, with locomotives with horsepower ratings of less than 4,000 making up the largest share.
Six-axle locomotives make up 68% of the North American locomotive fleet. Six-axle locomotives distribute the weight of a locomotive to the rails across more wheels and deliver tractive effort through more wheels and traction motors. Most six-axle locomotives were built in the past 30 years.
Locomotives with fuel capacity of more than 4,500 gallons make up 57% of the North American fleet. This share has grown in recent years, while the share of locomotives with fuel capacity between 3,500 and 4,500 gallons continues to decrease (down 5% since 2012). This is consistent with the recent trend of the fleet adding new high-horsepower, six-axle locomotives, which have larger fuel tanks.
Road Units and Switchers
To distinguish locomotives used in road service from those used in switching service, Railinc has applied the following definitions:
- A road unit is a locomotive with six axles and a horsepower rating of 2,500 or higher.
- A switcher is a locomotive with four axles and up to 2,500 horsepower.
Road units make up 67% of the North American locomotive fleet, while switchers account for about 23% of the population. Locomotives with four axles and a horsepower rating higher than 2,500 make up 9% of the fleet. However, the industry shifted away from making this locomotive type in the mid-1990s. Most additions of this type are refurbished units.
Railinc is a wholly owned subsidiary of the Association of American Railroads. For more information and to download this report, visit www.railinc.com.