The WDM-1 was the first class of Wide Gauge (W), Diesel powered (D), Mixed load (M), meant for hauling both freight and passenger trains. These are also the first mainline diesel engines imported after Independence. They were even the fastest diesel locomotives till the advent of WDM 2 and WDM 4. They used to haul ore/freight trains on SER. In the end, they were relegated to shunting/piloting duties or hauling sugarcane freight trains. One unit, #17000, is preserved at National Rail Museum, Delhi.[2]