Railinc Locomotive Report: Economic MirrorWritten by David Humphrey, Ph.D, Senior Data Scientist, Railinc Corp.
RAILWAY AGE MAY 2022 ISSUE: 2021’s minor fleet size decrease reflects COVID-19’s economic impacts and excess locomotive supply due to utilization improvements surrounding PSR (Precision Scheduled Railroading).
Railinc’s analysis of the North American locomotive fleet reveals that the size of the total fleet decreased slightly in 2021.
Detailed analysis reveals the following trends:
• At the end of 2021, the locomotive fleet totaled 37,988, down 465 units from 2020.
• The average age increased 1.1 years, to 29.2 years, and the median age also increased 1.0 years, to 24.8 years. This was the twelfth consecutive year the average and median ages increased.
• 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, accounted for most new additions to the fleet in the past decade. Finally, locomotives with the highest fuel capacity—more than 4,500 gallons—make up the largest percentage of the fleet.
When Railinc began reporting on locomotives in 2013, the size of the locomotive fleet was increasing each year. This paused in 2018, when the locomotive fleet decreased by three units and that decline continued in 2021—amounting to a –1.2% growth rate. Overall, in 2021, the number of locomotives decreased by 465 to 37,988 units. (See Figure 1, below).
Only five new locomotives joined the North American fleet in 2021, down from 77 the previous year (see Figure 2, below). It was the fifth consecutive year that the fleet added fewer than 500 new units.
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 2021 reflects both the economic impacts of the COVID-19 pandemic and the excess supply of locomotives due to industry utilization improvements surrounding PSR.
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 or refurbished.
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.
AC Units Continue Growth
DC traction locomotives make up 62% of the North American fleet, down 1% from the previous year. The share of AC traction locomotives has increased 12% since 2011 as more AC units join the fleet (see Figure 3, below).
Although DC diesel locomotives continue to account for nearly two-thirds of the North American fleet, AC locomotives have dominated among additions in the past 10 years. Only five DC units were added in the past two years, and in the past six years, about 96% of all new locomotives were AC units.
Locomotives with a horsepower rating of 4,000 or higher continue to make up the majority of the North American locomotive fleet. These locomotives comprised 56% of the fleet in 2021 (see Figure 4, below).
Locomotives between 2,000 and 3,999 horsepower comprised 33% of the fleet in 2021, down from 39% in 2011.
The fleet continues 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. Overall, 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—and locomotives with horsepower ratings of less than 4,000 make up the largest share.
Six-axle locomotives make up 68% of the North American locomotive fleet, the first time in a decade this share has remained stagnant. 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 6% since 2011). 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, and most additions of this type are refurbished units.
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