What is meant by the title article and the easter proverb " the arch never sleeps "

Well, an arch is a type of symmetrical composite of two halves. These two halves *have* to be very precise they must be balanced. If they're not, the structure does will collapse.

Back to the proverb, the proverb basically means the arch can't 'sleep', 'relax', or take a day off. 

Hope that helps.