Briefly about DEMU:
*DEMU is a self-propelled electric vehicle/coach used for urban transport.
*The lighter Coaches faster speeds and higher load carrying capability have made DEMUs very economic and passenger popular.
*It is economical for short rake information (3-car/ 6-car, 9 –car rake).
*It...
more... is also advantageous for running train in either direction without changing the loco position.
*This is almost similar to EMU. In EMU the source of power is overhead electricity, whereas in case of DEMU the source of power is the diesel engine.
*In 1994- 1995 they are first introduced in Indian Railways.
The benefits obtained from DEMUs are:
Fast and frequent service
No need for reversal at the terminals as it can be driven from either end
High acceleration
Ergonomically designed coaches
Low capital and maintenance cost
Efficient use of rolling stock
In Indian Railways DEMUs are available both of 700 HP and 1400 HP. In addition, 9 units of DHMUs (Diesel Hydraulic Multiple Units) are also operating in SC Railways.
☆Operating Parameters of 700 HP DEMU:
•Track Gauge : 1676 mm (broad)
•Composition of unit : 1 DPC – 1 TC + 1 DTC
(DPC: Driving Power Car, TC : Trailer Car, DTC: Driving Trailer Car)
•Passenger Capacity : DPC – 79, TC/DTC – 108
•Estimated Service weight : 188 Tones
•Maximum Axle Load : 17 T (DPC), 15 T (TC/DTC)
•Wheel Arrangement : BO-Bo
•Wheel dia : 952(New), 877 mm (Fully worn), 914.5 mm (Half worn)
•Effective traction power output : 610 HP
•Transmission : Electric AC/DC
•Max operating speed : 100 KMPH
•Clearance above rail level : Minimum of 102 mm with Coaches fully Loaded and wheels fully worn
Source: PDF from Goggle.
