Electrification is a clean and environmentally beneficial way of powering trains. The train draws power from the infrastructure supply system instead of carrying its own fuel.
There are two main types of electrification:
- Alternating current supply (AC) - electricity is supplied from overhead power lines, usually at 25,000 volts.
- Direct current supply (DC) - electricity is supplied from additional rails at track level (often called the “3rd rail” though some systems also feature a 4th rail) which are in contact with electricity collection equipment on the train, not its wheels. Current is usually supplied at
650 volts.
Electrified track miles defines the extent of the network that is electrified and the type of electrification.
Detailed information about this capability is shown in Table A of the Sectional Appendix published for the rail industry. For more information please see the National Electronic Sectional Appendix (NESA).