#Know_your_Locomotive
WDP-4B - 4500 Hp Passenger Loco
The EMD GT46PAC is a passenger-hauling diesel-electric locomotive with AC electric transmission designed by General Motors Electro-Motive Division and built by both GM-EMD and under license by Diesel Locomotive Works (DLW) of Varanasi, India for Indian Railways as their classes WDP-4, WDP-4B and WDP-4D. The GT46PAC is a passenger version of the previous Indian Railways EMD GT46MAC freight locomotive. The locomotive has a 16 cylinder 710G3B diesel engine with a maximum speed of 904 RPM.
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are three variants of this loco - the original WDP-4 which is a 4,000 hp (2,980 kW) loco, the WDP-4B which is a 4,500 hp (3,360 kW)126 t (124 long tons; 139 short tons) weighted loco with a single cab and the newest WDP-4D which is a 4,500 hp (3,360 kW) loco with dual cabs.
These locos are modified versions of the WDG-4 class locos, used for passenger operations. They have a reduced axle load of 20.2t (compared to the WDG-4's 21t axle load), achieved mainly by trimming the weight of the underframe. The gear ratio is 17:77, horsepower rating of 4500hp (brake horsepower 4150hp), and the maximum tractive effort is 384.4kN. It has an operational design speed of 130km/h and a maximum speed of 150km/h. The cab is slightly wider to provide better visibility when running long hood forward. All other features are essentially the same as with the WDG-4. Please see the WDG-4 class information for more details on this loco.
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#Performance
The WDP-4B is capable of hauling 24 coach trains at 115–120 km/hour. Irs Variant WDP4 has also been used for speed trials where it has hauled 8 coach trains at 160 km/hour.
The locomotives can be used in either direction, and frequently haul trains long hood forward, as in the picture. Newer editions with 4500 hp have been produced which have been named with the sub class WDP-4B /WDP-4D which have different traction control with six traction motors and are Co-Co bogie equipped (more similar to WDG-4), unlike the original which has a Bo-1-1-Bo arrangement with four traction motors. Due to some controversies regarding visibility hindrances faced by loco pilots in driving long hood front, the basic WDP-4B model has been modified to dual cab to eliminate any such possibility. Other features of WDP-4B and WDP-4D are same. The cabs have a slightly wider profiles, to improve visibility.
Some of the WDP-4B/WDP-4D are spotted having provision for an inverter-driven head-end power unit, allowing running trains without a generating car (EOG) for hotel power.
The loco is very fuel efficient and has minimal exhaust emissions unlike ALCO based locomotives, thanks to its its 2 stroke high efficiency diesel engine. It is characterized by its loud horn, which can be heard for large distances around, and aircraft-like sound of its running engine.
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#Criticism
The use of the locomotives "long hood forward" has been criticised because the driver might have difficulty in seeing signals. This criticism has been rejected by Indian Railways.[1] But the solution to this problem is to upgrade all WDP-4 and WDP-4B models from single cabins to WDP-4D models of dual cabins. Older locomotives of Indian Railways like the WDM-2 models have been upgraded from WDM-2 series to WDM-3 and WDM-3A series, to enhance other kinds shortcomings in design of WDM-2 series.
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#Diesel_Engine
16 Cylinder 710 G3B, 2 stroke, turbocharged after cooled
Fuel Efficient Engine
Injection System Direct Unit Injector
Governor Woodward
Compression Ratio- 16:1
Lube Oil Sump Capacity 950 Lts
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#Transmission
Electrical AC-AC
6 Traction motor ( 3 in parallel per bogie)
Suspension Axle hung / taper roller bearing
Gear Ratio 90:17
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#Brakes
Electronic Air Brake System ( KNORR-NYAB-Computer Controlled Braking)
Air , hand , dynamic brake
Pure air brake
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#General_Characteristics
Installed Power 4500 HP
Axle load 20.2 T
Gauge 1676 mm
Wheel arrangement Co-Co
Wheel diameter 1092 mm
Height 4201 mm
Width 3127 mm
Overall Length (Over Buffer Beam) 19964 mm
Maximum Speed 130-150 Km/hr
Weight 126 T
Fuel tank capacity 6000 lts
Gear ratio is 17:77
Locomotives made by DLW Varanasi
Pic:- WDP 4B hauled with Mandovi Express (both pics)