Head End Power
In NARS, passenger carriages require power for heating and lighting. This power is provided by the train's locomotive, and will either increase the running cost, decrease the horsepower, or both.
|Carriage Type||HP reduction||Running cost^|
|Passenger Car with steam heating||50hp (dynamo under car)||$350 per year|
|Passenger Car with HEP from traction system||100hp||$125 per year, only incurred when train is stationary|
|Passenger Car with HEP from seperate system||none||$700 per year|
|Bilevel Car with steam heating||100hp (dynamo under car)||$700 per year|
|Bilevel Car with HEP from traction system||200hp||$350 per year, only incurred when train is stationary|
|Bilevel Car with HEP from seperate system||none||$1400 per year|
Steam locomotives and early diesel and electric locomotives provide steam heating (the diesels and electrics have special steam generators for heating), and electrical power for lighting is generated by dynamos under each car. Locomotives built after 1970 have HEP (Head End Power) provided by either the traction system or a seperate HEP generator. HEP provides electrical power for both heating and lighting.
- Diesel and electric locomotives without a steam generator or an HEP system cannot haul passenger trains.
- Steam locomotives, Doodlebugs, Interurbans and Boxcab electrics retain steam heating even if built after 1970.
- The UAC TurboTrain has HEP even if built before 1970.
- The RDC, Metroliner and EMUs generate their own power in each car, and so do not have any additional costs.
^uninflated 1921 dollars, with vehicle running costs on medium.