Thomas & Friends (1984)

S3E15 Toby's Tightrope

Mavis learns that she’s prohibited from going near Toby’s track, so she devises a scheme to have the trucks propel her there. However, Toby inadvertently ends up with those trucks, and they opt to push him forward instead. As Toby races down the track, he notices that the bridge ahead is crumbling, and he quickly understands he won't be able to halt in time!