Thomas & Friends (1984)

S1E4 Edward, Gordon and Henry

Henry feels disheartened being trapped in the tunnel, while Gordon takes pleasure in mocking him each time he rolls by. One fateful day, Gordon's safety valve unexpectedly bursts just outside the tunnel. With no other engines around to help, Edward steps up, but he realizes that the load is too much for him to handle alone. Will Edward find a way to tackle the challenge and save the day?