Work train. A work train (departmental train or engineering train/vehicles in the UK) is one or more rail cars intended for internal non-revenue use by the railroad's operator.  Work trains serve functions such as track maintenance, maintenance of way, revenue collection, system cleanup and waste removal, heavy duty hauling, and crew member transport.

Types of equipment

Track inspection
A number of railroad vehicles are used in the inspection of railroad tracks and infrastructure to identify flaws and areas in need of routine maintenance.
 Rail inspection cars and Sperry rail cars - Inspects tracks for flaws and defects.
 Rail bridge inspection - Rail vehicles that have specialized equipment, such as Aerial work platforms to enable access the bridge.
 Dynamometer cars - Rail car that measure locomotive performance, such as traction effort, speed, etc.
 Track geometry cars - Rail car that collects information on track properties, such as banking of curves, grade, etc.
 Scale test cars - Rail car that is built to be an exact weight, used to test railroad car scales for accuracy.
 hi-rail trucks/SUVs - Road vehicles that are able to also be driven onto train tracks.

Track maintenance and renewal
Track maintenance and renewal trains often consist of many pieces of separate equipment that are capable of servicing specific track components.
 Ballast regulators - Distributes ballast to a desired shape and position.
 ballast tampers - tamps or levels and compacts ballast to make the trackbed more secure.
 Ballast cleaners - Collects and cleans ballast to prolong its life and improve drainage by removing debris.
 Cranes - Rail mounted cranes.
 Ballast hopper - A specialized hopper car that is designed to spread ballast between rails and to the sides of rails, and the ability control ballast flow.
 Rail grinders - Uses grinding wheels to restore rails back to a ideal shape, extending life time of the rail.
 Spreaders - Rail based plow that is used to move ballast and create ditches beside train tracks.
 Side dump cars - Rail car that was built so that it can dump it's load, often ballast, to the side, at any location.
 Spike puller - Pulls out spikes from railroad ties.
 Spike driver - Inserts new spikes into railroad ties.
 Tie exchanger - Removes and inserts railroad ties from under rails that are already in place.
 Continuous welded rail trains - Specially modified flatcars for carrying long sections of continuously welded rail for installation, often accompanied by flatcars with equipment for welding sections of rail together.
 Track renewal train - A train capable of doing multiple tasks to replace multiple track components (ties, rails, spikes, etc).

Snow removal
Trains are susceptible to issues related low rail traction as well as being immobilized by significant snowfalls.
 Wedge plows - A simple V-shaped plow, pushed by one or more locomotives.
 Flanger - A rail car that removes snow and ice from between rails.
 Spreaders - Spreaders can also be used for snow removal, offering more control over where the snow can be directed.
 Snow blower - A machine that uses augers or impellers to throw the snow clear of tracks.
 Rotary snowplows - A type of snow blower, that uses a massive rotating blades to cut through and throw snow clear of tracks.
 De-icer cars - Rail cars that use chemicals or heat to melt snow and ice on tracks.
 Rail adhesion cars - Rail cars that are used to address areas of low rail traction.

Vegetation control
The uncontrolled growth of weeds and other vegetation along railroad right-of-ways can cause significant issues with drainage, obstruct worker access and become a nuisance to adjacent property owners.
 Weed spraying trains - Trains that deploy weed killer in order to control the growth of weeds on railroad tracks and ditches along tracks.
 Bush cutters - Used to cut weeds and other vegetation from railroad tracks and ditches along tracks, using blades or saws.

Other railroad cars

In addition to specialized equipment above, most railroad has have allocated regular rail cars and locomotives to railroad maintenance duties. This is often older equipment that has either reached the age limit that prohibits it from interchange with other railroad, and is required to stay on the railroad that owns it, or equipment that has been rendered obsolete by newer, often higher capacity versions: tank cars, * flatcars, hoppers, gondola, boxcars as well as locomotives.

Railroads have historical kept rail mounted cranes of various sizes, to assist with maintenance work, major construction projects as well as respond to derailments and natural disasters. These have in large part been displaced by a mixture of road biased mobile cranes and sideboom bulldozers.

Beyond typical railroad cars, hi-rail technology has allowed railroads to put conventional heavy equipment such as excavators, mobile cranes, bucket trucks, Concrete mixers, etc, right onto the tracks.

Subways and metros
In addition to variety of equipment above, subways often have specialized equipment intended to address unique issues within subway systems, such as the difficulty in removing trash from underground stations.
 Trash collection trains - Trains that visit stations to remove trash. 
 Revenue collection cars - Trains that visit stations to collect money collected from turnstiles and ticket sales. 
 Vacuum cars - A rail car that vacuums up litter and dropped objects from the tracks, as they accumulate in the closed environment of a subway tunnel. 
 Flood cleanup cars (reach cars, pump cars, hose cars) - Trains deployed to remove water following tunnel flooding.

Gallery

See also 
 List of railway vehicles
 Non-revenue cars
 Plasser & Theurer
 Rail inspection
 Track renewal train

References

External links

Maintenance of way equipment
Railcars