Indian locomotive class WAP-4
| WAP-4[1] | |
|---|---|
|
A WAP - 4 class locomotive 22820 of Indian Railway belonging to Royapuram shed, bringing the Trivandrum - Nagercoil Passenger train to Nagercoil Junction | |
| Type and origin | |
| Power type | Electric |
| Builder | Chittaranjan Locomotive Works, West Bengal, India |
| Build date | 1990 till present |
| Total produced | 698 |
| Specifications | |
| AAR wheel arr. | C-C |
| UIC classification | Co'-Co' |
| Gauge | 5 ft 6 in (1,676 mm) |
| Bogies | Co-Co Flexicoil Mark 1 cast bogies; primary and secondary wheel springs with bolsters |
| Wheel diameter |
New:1,092 mm (3 ft 7 in) Half worn: 1,055 mm (3 ft 5 1⁄2 in) Full worn: 1,016 mm (3 ft 4 in) |
| Length | 18.794 m (61 ft 7 29⁄32 in) |
| Width | 3.179 m (10 ft 5 5⁄32 in) |
| Height | 4.232 m (13 ft 10 5⁄8 in) |
| Axle load | 18,800 kg (41,400 lb) |
| Locomotive weight | 112,800 kg (248,700 lb) |
| Electric system(s) | 25 kV 50 Hz AC AC Overhead |
| Current collection method | pantograph |
| Traction motors | Hitachi HS15250 |
| Performance figures | |
| Maximum speed |
Service: 140 km/h (87 mph) Test Runs: 180 km/h (112 mph) |
| Power output |
Max: 5,350 hp (3,989 kW) Continuous: 5,050 hp (3,766 kW) |
| Tractive effort | 32,000 kgf (310 kN; 71,000 lbf) |
| Locomotive brake | Air/Hand |
| Train brakes | Air |
| Safety systems | Slip control, Over voltage relay, Main overload relay, Earth Volt Relay, Low Pressure Governor, Brake Cylinder Cutoff Valve, Train parting alarms and No volt relay |
| Career | |
| Operator(s) | Indian Railways |
| Number(s) | 22061 and from 22201 to 22980+ |
| Locale | All over India |
| Disposition | Active |
WAP - 4 is a common electric locomotive used in India. It is capable of hauling 26 coaches at a speed of 140 km/h.
The locomotive was developed, after a previous class WAP-1 was found inadequate to haul the longer, heavier express trains (24 - 26 coaches) that were becoming the mainstay of the Indian Railways network. It was introduced in 1994, with a similar bodyshell to the WAP-1 class, but with Hitachi traction motors developing 5,000 hp (3,700 kW) (5,350 hp or 3,990 kW starting).
Electricals are traditional DC loco type tap changers, driving 6 traction motors arranged in Co-Co fashion. This locomotive has proved to be highly successful, with over 800 units in service and more being produced. Newer examples have been fitted with Microprocessor Controlled diagnostics, Static Converter units (instead of arnos) and roof mounted Dynamic (Rheostatic) Brakes.
The locomotive can be seen in service across the electrified network of Indian Railways and are homed at 14 sheds (depots).
It was also designed to eliminate the need for bankers.
Design
The loco has a streamlined twin cab carbody design, with top-mounted headlamps. The first 150 or so units had the headlamp mounted at waist level, with the lights being mounted in a protruding nacelle. Some earlier locos, especially from the Erode loco shed have the headlamps placed on the top. Later on the headlamps were placed in a recessed nacelle, and from road # 22579 onward, the headlamps were moved to the top. Also they have digital notch repeaters.
Newer locos also feature larger windshields, more spacious driver cabin with bucket type seats and ergonomic controls. The control panel also features a mix of digital and analog displays in newer units (all analog display in older versions).
The loco features higher power rated silicon rectifiers and indigenously-designed 5400 kVA transformer coupled with Hitachi HS15250 traction motors. Starting power is 5,350 hp (3,990 kW), with 5,000 hp or 3,700 kW being supplied continuously.
Original units were weighed 120 tonnes, which was brought down to 112 tonnes through the usage of lighter material.
Some of the WAP-1 and WAP-3 and all the WAP-6 units were rebuilt to WAP-4 specifications after replacing the bogies & electricals.
It has different underframe for handling larger buffing loads. Some units are fitted with speed recorders and some changes to control electronics. Some units also have data recorders for energy consumption. Some are even fitted with windshield washers. Few were provided with signalling lamps.
Technical variants include WAP-4E which are probably fitted with electronic sensor for sensing loss in pressure in pipes.
The Hitachi traction motors are the ones used on freight engines. It was a challenge to put these in a passenger engine due to weight constraints. So the transformer is aluminum foil-wound and aluminum chequered plates are used for reducing the weight. These traction motors were more reliable so WAP-7.
Performance
The class is used to haul the premier Rajdhani & Shatabdi expresses at 140 km/h (87 mph). In trials, the locomotive has achieved a top speed of 169 km/h (105 mph), though Indian Railways limits its top speed to 140 km/h (87 mph).
With a 24 coach passenger train, the acceleration time / distances are (*):
110 km/h - 198 seconds (4.8 km)
120 km/h - 260 seconds (7.5 km)
130 km/h - 445 seconds (13.5 km)
Starting Tractive Effort (Te) - 32000 kg/force
(*) Conflicting data observed in practice, further verification required.
If the average weight of ICF coach is 55 tonnes then it can haul the following capacity in tonnes:
| Grade\KPH | Start | 20 | 40 | 60 | 70 | 80 | 90 | 100 | 110 | 120 | 130 | 140 | 150 | 160 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Level | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1155 | 805 | 570 |
| 1 in 500 | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1105 | 805 | 565 | 400 |
| 1 in 200 | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1320 | 1230 | 1035 | 730 | 535 | 375 | 260 |
| 1 in 150 | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1500+ | 1405 | 1090 | 1020 | 860 | 610 | 445 | 310 | 215 |
| 1 in 100 | 1500+ | 1570 | 1490 | 1405 | 1365 | 1195 | 1020 | 795 | 750 | 635 | 445 | 320 | 220 | 145 |
| 1 in 50 | 1160 | 770 | 750 | 720 | 710 | 625 | 530 | 410 | 390 | 325 | 220 | 150 | 90 | 45 |
Technical specifications
| Gear Ratio | 23:58 (One loco, #22559, was said to have a 23:59 ratio but now it is 23:58) |
| Transformer | 5400 kVA, 32 taps |
| Transformer cooling | Forced oil with Forced Air |
| Transformer Insulation | A |
| Pantographs | Two Stone India (Calcutta) AM-12. |
| Rectifiers | Two silicon rectifiers |
| Rectifier Cooling | Forced air |
| Pantographs | Two Stone India (Calcutta) AM-12. |
| Current Ratings | 1000 A for 10 min, 900 A continuous |
| Drive arrangement | Gear pinion |
| Number of sandboxes | 4 |
| 2 headlights | 90 W, 24 V |
| Lead acid battery | 50 cells |
| Arno Converter | 1420 rpm |
| 2 Elgi Compressors | 1000 l/minute at 7.5 kg/cm2. |
| 2 compressor motors | 3 phase 12.5 hp and 380 V |
| 2 SF India Ltd. Traction motor blowers | MLBR-42.5-144 type |
| 2 Siemens Traction motor blower motors | 22 kW, 415 V, 50 A and 2820 rpm |
| 2 SF India Ltd. Smoothing Reactor Blower | PFTA-50, ARR6 type |
| Traction Motor Suspension | Axle-hung, nose suspended |
| Traction motor weight | 3650 kg |
| Armature temperature rise | 90 °C |
| Field temperature rise | 70 °C |
| Commotator temperature rise | 85 °C |
| Armature coil resistance at 110 °C | 0.0126 ohms |
| Field coil resistance at 110 °C | 0.0117 ohms |
| Commotator coil resistance at 110 °C | 0.089 ohms |
| Traction motor continuous rating | 630 kW, 750 V, 900 A and 895 rpm |
| Traction motor 1 hour rating | 870 hp, 750 V and 877 rpm |
| Traction mMotor air gap main place | 6.35 mm |
| Traction motor air gap inter-pole | 10 mm |
| Traction motor | 6 P |
| 2 SF India Ltd. silicon rectifier blower | 3100–3200 m/hr |
| 2 Rectifier blower motor | 22 kW, 415 V, 8 A, 2860 rpm and 60 kg(approx) |
| Oil cooler blower motor | 30 hp, 380 V, 43 A and 1450 rpm |
| BEST and Co. Pvt. Ltd. Transformer Oil Pump | 750 l/minute |
| Oil pump motor | 3.3 kW, 415 V, 6.6 A and 2865 rpm |
| SL-30 type smoothing reactor | 1250 V and 1350 A. |
| Smoothing reactor resistance at 110 °C | 0.00718 ohms |
| Notches | 32 |
Image Gallery
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Indian locomotive class WAP-4 (22592)
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Indian locomotive class WAP-4 (22237)
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Indian locomotive class WAP-4 (22685)
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Indian locomotive class WAP-4 (22595)
Sheds Holding WAP-4
Sheds holding WAP4s as of April 2015 :
| Shed | Number of locos | Railways |
|---|---|---|
| Erode (ED) | 108 | Southern Railway (SR) |
| Howrah (HWH) | 91 | Eastern Railway (ER) |
| Santragachi (SRC) | 73 | South Eastern Railway (SER) |
| Vadodara (BRC) | 66 | Western Railway (WR) |
| Lallaguda (LGD) | 60 | South Central Railway (SCR) |
| Mughalsarai (MGS) | 59 | East Central Railway (ECR) |
| Ghaziabad (GZB) | 52 | Northern Railway (NR) |
| Itarsi (ET) | 50 | West Central Railway (WCR) |
| Kanpur (CNB) | 42 | North Central Railway (NCR) |
| Royapuram (RPM) | 40 | Southern Railway (SR) |
| Bhusawal (BSL) | 42 | Central Railway (CR) |
| Visakhapatnam (VSKP) | 15 | East Coastal Railway (ECoR) |
| Tatanagar (TATA) | 3 | South Eastern Railway (SER) |
| Ludhiana (LDH) | 3 | Northern Railway (NR) |
Accidents and incidents
On 13 February 2009 Coromandel Express derailed near Jajpur Road about 100 km away from Bhubaneswar in Orissa killing at least 15 people and leaving several injured, some critically. The train was hauled by Santragachi based WAP 4 22330 locomotive which got damaged beyond economical repair and therefore had to be condemned.
See also
References
Notes
- ↑ "Trainweb".
- ↑ "Indian AC electric loco information". Irfca.org. Retrieved 2013-04-03.
Bibliography
- Hughes, Hugh (1996). Indian Locomotives: Part 4 – 1941–1990. Harrow, Middlesex: The Continental Railway Circle. ISBN 0-9521655-1-1.
External links
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