Thomas Engineer's Sling Bridge Set with Play Board. 54 Piece Set Includes Sling Bridge: Turn the knob to raise and lower the sling bridge and allow trains to pass over and under. Oil Depot: The oil level rises and falls as you move the lever back and forth when attending to the engines. Arched Viaduct Bridge Thomas Mike and his tender NW Brake Van Cargo Truck: With magnetic Cargo Signs, Trees, Sir Topham Hatt and 2 Engineers