The Uig Class of cargo ships are an upgrade to the Carrack with more firepower and better fire control, aswell as larger cargo bays. They also had much more reliable turbines installed, as newer more precise tools had been develloped. However they still had teething problems to begin with and captains often prefered medium to short journeys, rarely making long journeys as the mark 1 steam turbines guzzled fuel. Later on the fuel consumption dropped dramatically as newer better turbines were installed.