Conway Yard, northwest of Pittsburgh, was the Pennsy’s major classification yard, at one time the largest yard in the country. Under Conrail and now NS, it is second only to the UPs Bailey yard. At the time of this program, there were two hump classification yards. At the west end of the yard, Rochester Interlocking controlled access from the Cleveland and Ft. Wayne lines. At the east end, Leets Interlocking controlled access. Chester Kamuda was allowed full access to the yard to shoot the action. Sometimes, there are as many as four train movements at the same time..