The Alco T6 (DL 440) is a diesel-electric switcher locomotive rated at 1,000 horsepower (750 kW), that rides on two-axle trucks, having a B-B wheel arrangement.

The 'T' stands for 'Transfer', meaning this locomotive is capable of faster transition and higher sustained speeds than the regular 'S' - type yard switcher series.

The 752 motors give the T-6 a very substantial increase in continuous tractive effort, which greatly improved its slow-speed lugging performance.

It was that railroad's first locomotive acquisition and is often used to switch the NewPage paper mill at Luke, Maryland.

It has been restored to Norfolk and Western lettering and makes operating appearances at the Virginia Museum of Transportation.