MT-4 Slug
In 1978 Conrail began rebuilding worn-out Alco RS-11, RSD12, and RSD-15 units into traction motor slugs. Four-axle slugs were classed MT-4 (Motor Trailer 4-axle).
Photos | Prototype Info & Roster
MT-6 Slug
Conrail classified their six-axle slugs as MT-6 (Motor Trailer 6-axle). They also inherited two EL slug units that never made the roster and a PC RSD-5 slug.
Photos | Prototype Info & Roster
DS4-4-1000
Ironton 751 was the only surviving Ironton engine on Conrail and was Conrail's only DS4-4-1000, also known as an S10. It was never renumbered into Conrail and was retired in its Ironton colors.