Model of a Pacific Class Broad-gauge Steam Locomotive. Pacific Class of broad gauge loco marked the change the coding from 'X' to 'W' for broad gauge locomotives. Built by Baldwin Locomotive Works (BLW), Philadelphia, these locos were capable of doing up to 110km/h and remained Indian Railways crack locomotives for many years and hauled prestigious express trains. WP's were designed specifically for low-calorie, high-ash Indian coal and its ease of handling made it a hot favorite amongst Loco drivers. Several WP's remained in service until the late '80s.