The DPU for an eastbound empty coal train shoves out of West Scenic and into the 7.8-mile long Cascade Tunnel. Extra knuckles are in their respective places: one space on the left for an "F" type knuckle, and one space on the right for an "E" type knuckle. Each knuckle weighs upwards of 75 pounds, and each type fits into its respective coupler. A "F" knuckle fits tightlock and shelf couplers, while a "E" type fits just about everything else. Think about what conductors have to go through when they break a knuckle 80 cars back.
