Deccan Queen - मेरे सपनों की रानी

WAP stands for - Wide - AC Traction - Passenger
WDM - Wide-Diesel-Mixed
WAG - Wide-AC- Goods
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Classification Syntax:
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first letter (gauge)
W – Indian broad gauge (the "W" Stands for Wide Gauge - 5 ft 6 in)
Y – metre gauge (the "Y" stands for Yard Gauge - 3 ft or 1000mm)
Z – narrow gauge(2 ft 6 in)
N – narrow gauge (toy gauge) (2 ft)
The second letter (motive power)
D – diesel
C – DC electric (can run under DC overhead line only)
A – AC electric (can run under AC overhead line only)
CA – both DC and AC (can run under both AC and DC overhead line); 'CA' is considered a single letter
B – Battery electric locomotive (rare)
The third letter (job type)
G – goods
P – passenger
M – mixed; both goods and passenger
S – shunting (also known as switching engines or switchers in the USA and some other countries)
U – multiple units (EMU/DMU)
R – Railcars
For example, in "WDM 3A":
"W" means broad gauge
"D" means diesel motive power
"M" means suitable for both goods and passenger service
"3A" means the locomotive's power is 3,100 hp ('3' stands for 3000 hp, 'A' denotes 100 hp more)
Or, in "WAP 5":
"W" means broad gauge
"A" mean AC electric traction motive power
"P" means suitable for Passenger service
"5" denotes that this locomotive is chronologically the fifth electric locomotive model used by the railways for passenger service.
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