Complex sentence: The small companies were joined to form "The Triumph Mining Co" who at, its WW2 peak, employed 200 men, 24 hours a day, and held the world record for Zinc.
Split into simpler sentences: The small companies were joined to form "The Triumph Mining Co". At its WW2 peak, "The Triumph Mine" employed 200 men, 24 hours a day and held the world record for Zinc.