Corrected entry: When Superman saves the train from derailing during the earthquake, he places his body between the tracks, hold up one rail with his right hand, and uses his left arm and side as the other rail. But even Superman can't change physics. Train wheels have a flange that goes on the inside of the rail to keep it from slipping off the rail. (Go look at your model train set). Since Superman is indestructible, this flange would hit him and derail the train (Perhaps this is why he ducks his head).
Rlvlk
23rd Jun 2006
Correction: And when he grabs the plane to help it fly, he would punch right through the skin. And, and, and... Every single thing he does in the movie is against the laws of our reality, but some leeway has to be given for movies like this.
Rlvlk