Ballast - Definition and Overview

Ballast may mean:

• track ballast: gravel or cinders forming the railroad or railway track-bed on which sleepers (ties) and track is laid, for proper drainage
• ship's ballast: water, sand, rocks, or bricks used to weight a ship down when it has very little cargo (though water may contain invasive species of pests)
• electrical ballast: a component used in an electric circuit to limit the current flow in another electrical component. See resistor, leakage inductance, transformer or inductor. For specific application information, see neon lamp, fluorescent lamp, mercury-vapor lamp, sodium lamp, or high-intensity discharge lamp.