INJURED WAS ATTEMPTING TO CLOSE LEAKING BOTTOM GATE ON BULK C-6 RAILCAR USING A SLEDGEHAMMER. HE PLACED HIS LEFT FOOT AGAINST GATE TO GIVE IT CONTANT PRESSURE. WHILE TRYING TO GET GATE CLOSED, HAMMER HEAD GLANCED OFF CAR STRIPKING TOP OF HIS LEFT FOOT, JUST ABOVE HIS STEEL TOE CAP.