Power at rail

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The power at rail is the amount of power which a train applies to achieve the tractive effort.

Power at rail is measured in kilowatts.

The power at rail of a train follows the equation power (kW) = force (kN) x speed (m/s)

1 Diesel locomotives
2 Steam locomotives
3 See also
4 External links

[edit] Diesel locomotives

A sample of UK rail locomotives are included on the below table to illustrate their power at rail.

Class	Type	Top speed		Maximum tractive effort	Speed to reduce tractive effort	Continuous tractive effort	Maximum power at rail	Mass
Class	Type	km/h	mph	Maximum tractive effort	Speed to reduce tractive effort	Continuous tractive effort	Maximum power at rail	Mass
Class 08	Shunter	24	15	156 kN	14.2 km/h	49 kN	194 kW	49.6 - 50.4 t
Class 33	Passenger	137	85	200 kN	28.2 km/h	116 kN	906 kW	77.7 t
Class 56	Light freight	129	80	275 kN	27 km/h	240 kN	1790kW	125.2 t
Class 58	Light freight	129	80	275 kN	28 km/h	240 kN	1780 kW	130 t
Class 59	Heavy freight	97 or 121	60 or 75	506 kN	23 km/h	291 kN	1889 kW	121 t
Class 60	Heavy freight	97	60	500 kN	28 km/h	336 kN	1800 kW	129-131 t
Class 66	Heavy freight	121	75	409 kN	25.6 km/h	260 kN	1850 kW	126 t
Class 67	Light freight	201	125	141 kN	??	90 kN	1860 kW	90 t

The power at rail only includes the power which reaches the rail to create tractive effort and excludes power which is used for heating, cooling, lighting, etc. and also excludes power wasted by inefficiencies of the vehicle (including the production of sound and heat energy).

[edit] Steam locomotives

British railway companies showed a curious reluctance to reveal horsepower figures for their steam locomotives but these are believed to have been in the range 2,000 to 2,500 horsepower (1500-1875 kW) for the largest locomotives. The largest American articulated locomotives are believed to have delivered around 6,000 horsepower (4,500 kW), equivalent to three or four contemporary diesel locomotives.