The light had a range of . Illumination was provided by a pair of Douglass-designed six-wick concentric oil burners (one for each tier of the optic). This was said to represent 'the first practical application of superposed lenses of the first order with oil as the illuminating material'. On clear nights, only the lamp in the lower tier of lenses was lit (producing a light of 37,000 candlepower); in poor visibility, however (judged by whether the Plymouth Breakwater light was visible), both lamps were used at full power, to provide a 159,600 candlepower light. Eighteen cisterns in the lower part of the tower were used to store up to 2,660 tons (nine months' worth) of colza oil to fuel the lamps.