This song is called "Dead Man's Boots," which is an expression which describes how difficult it is to get a job; in other words, you'd only get a job in the shipyard if somebody else died.
Esta canción se titula "Las botas del muerto", y es una expresión que describe lo difícil que es conseguir un empleo; en otras palabras, uno solo consigue un empleo en el astillero si alguien muere.