As Class 1 railroads have embraced the precision scheduled operating model they have also reduced the sizes of their locomotive fleets.
Those who closely follow the quarterly financial reports of Class 1 railroads may have noticed that a shrinking locomotive fleet has become a regular feature.
Norfolk Southern, for example, reported that its active locomotive fleet at the end of March was 20 percent smaller than it was in late 2018.
That’s 714 fewer units in case you were wondering.
Similar trimming of the active motive power fleet has also happened at CSX.
Yet these locomotives don’t vanish from the face of the earth. Some wind up on other railroads, notably short lines and regionals, while others are snapped up by locomotive leasing firms.
Railinc Corporation, a subsidiary of the Association of American Railroads, keeps track of the North American locomotive fleet.
Its latest report shows the number of diesel-electric locomotives is 39,125, a decrease of 393 units from 2018.
The nation’s locomotive fleet is getting older with the average age rising by 0.7 years to 27.3.
The median locomotive age is 23 years, an increase of 0.2 percent.
Railinc said this is the 10th consecutive year the average and median ages of the nation’s locomotives has risen.
In large part that is because railroads are buying fewer new locomotives.
Last year railroads bought 244 new locomotives whereas in 2018 they purchased 164. Last year was the third consecutive year that railroads bought fewer than 300 new units.
Railinc has been tracking locomotive fleet size since 2009.
The size of the nation’s motive power fleet grew every year until 2018 when it began falling.
Age and size of locomotives tend to correlate with the economy. When it’s strong and railroads have more rail cars in service, the average age of the motive power fleet tends to be lower and the number of units grows.
But when the economy falters the inverse tends to be true although a lagging economy doesn’t explain what happened the past two years.
Railinc attributes that to what it termed “ industry utilization improvements,” which is another way of saying railroads are using fewer locomotives to pull their trains.
That is linked to PSR at Class 1s, which are running fewer, but longer, trains.
Since the mid-1990s, most new locomotives have been six-axle units with a horsepower rating of 4,000 or higher.
Units with 4,000 or more horsepower now account for 56 percent of the overall North American fleet while six-axle units are 69 percent of the fleet.
Most of those new units have alternating current traction motors, which perform well hauling heavy loads.
Direct current traction motors still make up 64 percent of the North American fleet. Yet the share of AC units has grown by 10 percent since 2009.
Only 39 new DC units have joined the North American locomotive fleet over the past two years.
Most new units also have featured a fuel capacity of more than 4,500 gallons.
The Railinc analysis, which was published by Railway Age, noted that Class 1 railroads often use newer locomotives for long hauls but as those units age they can be relegated to lighter duties.
It is not unusual, though, for a locomotive to have a service life of more than 60 years.
Road units account for 67 percent of the North American Fleet with switchers making up 22 percent.