A self-propelled piece of maintenance-of-way equipment used to pack ballast firmly under railroad ties. As the machine travels down the track, vibrating metal tines plunge into the rock, squeezing it upward against the bottom of the ties. This restores the track to its proper alignment and elevation, ensuring a smooth and stable ride for heavy freight.
Heard on the job
The dispatcher is holding us at the siding because there's a tamper working the main ahead of us.
Also heard as
- tamping machine
Related terms
Ballast
The bed of crushed rock under and around the ties that holds the track in line and drains water away.
MOW
Maintenance of way: the department and crews that build and maintain track, bridges and roadbed.
Tie
One of the crosswise beams that hold the rails to gauge and spread their load into the ballast.