C L W  IN PURSUIT OF EXCELLENCE SINCE ITS BIRTH--------- INNOVATION IS OUR MOTTO-----    

                       WAG_9H  6000 HP Freight Locomotive 

Indian Railways  imported 22 high capacity freight Locomotives from ABB Transportation Systems Ltd. Switzerland under a contract in July 1993 which included  Transfer of Technology  to permit Indian Railways to indigenously manufacture two types of locomotives WAG 9 and WAP 5 . This was a new technology with higher tractive effort regenerative braking system , microprocessor controls and sophisticated design requiring less maintenance contributing to more revenue and ease of operation. These Locomotives have a  maximum potential starting tractive effort is 520 kN and can be controlled by a microprocessor based stepless control.  to haul 58 loaded BOXN wagons with a single locomotive   CLW successfully absorbed  this new technology as usual and produced its first WAG 9h  class locomotive christened " NAVSHAKTI" on 17th. May 2000. 

THE NECESSITY

Indian Railways had been using WAG5 and WAG7 locomotives for freight service. These were powered by direct traction motors and are rated 3900 and 5000 HP respectively with a speed of 100 kmph. Due to low power, poor adhesion ,control and old tap changer technology, they needed multiple operation in many section graded above 1 in 200 specially in the freight originating mining/colliery areas. IR needed some locomotive which will overcome these difficulties. WAG-9 class of locomotives were produced with increased power 6000 HP , microprocessor based stepless control which were capable of hauling 58 BOXN rake  in a graded section of 1 in 180. But there were sections with a grade of 1 in 150 and again these required a banker or multiple operation. 

WHAT WAS DONE AT CLW  

 The Engineers at CLW found that the main task to improve the WAG-9 version was to increase the starting tractive effort from 460 KN to 520 KN and this was possible by increasing the adhesive weight of the loco from 123 t to 135t . A design was evolved at RDSO and ADtranz approved the design. Adhesion of 12 tonnes was achieved by welding ballast weights  at 4 locations inside the machine room and behind the Cabs. But this was not that easy . The addition of weights needed strengthening of suspension arrangements and springs.  The changed performance characteristics called for modification of application software. All these were done at CLW with in-house skill.  

 
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ADVANTAGE

The 3-phase system provides a lot of advantages.                

1. Efficiency : Overall efficiency is increased by 5%

2. Savings in operation : IR is paying the SEBs in terms of "Maximum Demand" only , which speaks of high quantity and its reflection in bills. The new locomotives are regeneration type and and having unity power factor. Approximately 15% to 20% energy is conserved through regeneration while braking. Thus there will be a lot of savings.

3. Less maintenance of traction motors due to absence of commutator and brushgear.

4. Easy maintenance hence better availability. Normally  lifting is not required during attention to failures saving a lot of time.  

5. The traction motor is maintenance free. Therefore improved reliability.  

6. Low unsprung masses result in minimum wear on rails.  

                                                                                                         Traction Motor for WAG9       
                                                                                                            manufactured at CLW

Special diagnostics

7. Automated fault isolation.

8. Display terminal in Driver's Cab. Drivers get assistance during faults and rectification.

9. Diagnostic Computer to log faults and this can be uploaded to a PC in the shed/workshops for 

     better fault  identification

These Locomotives require special skill and equipments during maintenance and can be done only in equipped sheds. Presently all WAG9 locos are homed at GOMOH
  
VITAL STATISTICS

Steam            Diesel         Electric       Milestones      WAG-5    WAG-7    WAG9h     WAP4        WAP5       WAP7   

   3 Phase Technology