Engineers pride themselves in making smooth stops right on the spot, keeping the passengers - and the conductor - happy. It became a real problem when the C&NW put second-hand E-units from Uncle Pete (Union Pacific) into suburban service. Scoots were all equipped with composition brake shoes - not unlike what you've got on your automobile - cars and locomotives alike. Deceleration was smooth and uniform right down to the final stop. But the Union Pacific locomotives had the old cast iron brake shoes. At speed they felt ineffective, but as the train slowed, those iron shoes would take hold. Very hard. Station stops resembled collisions with a brick wall. Attempts to bail off the engine brake right as the train stopped could not be done consistently. Eastbound trips, run from the cab car, were even worse, since the Engineer could not bail off the engine brake at all. It felt like we'd dropped an anchor on a short chain, and we fully expected to look back and see a cloud of ballast and splintered crossties behind the engine. Since the engine squatted down when it stopped, it would run all the slack out of the train. Starting up again, we could feel the slack come up car by car until it hit the cab car with a good tap. The mechanical people at the diesel ramp (M19A - 40th Street, Chicago) were flooded with complaints, and it wasn't long before those UP engines all had composition brake shoes and new brake cylinders.