High voltage distribution networks use fixed electrolyte resistors to ground the neutral, to provide a current limiting action, so that the voltage across the ground during fault is kept to a safe level. Unlike a solid resistor, the liquid resistor is self healing in the event of overload. Normally the resistance is set up during commissioning, and then left fixed.
Modern motor starters  are totally enclosed and the electrode movement is servo motor controlled. Typically a 1 tonne tank will start a 1 megawatt slip ring type motor, but there is considerable variation in start time depending on application.