A5550 HP locomotive, WDG, is being developed by RDSO in association with DLW, Varanasi and EMD/USA. First such locomotive with speed potential od 90kmph has been commisioned at SBI shed in March 2015. To further increase the speed potential RDSO has proposedd certain modifications to the carbody to improve the natural frequency of the underframe. Second locomotive with the proposed modifications has beenmade and RDSO has issued a speed certificate for conductind oscillation trials in South Central Railway. On receipt of CRS sanction, oscillation trials will be planned by RDSO on priority.