The compound engine was unusual at the time for a British vessel. Carnatic's boiler ran at only . Higher pressures were not allowed by the Board of Trade. The advantages of a compound engine were not fully realised at this low pressure - but the solution to the problem was to apply a large amount of superheat. The efficiency gained was a fuel usage of just over 2lbs of coal per indicated horsepower-hour. This is comparable to the achievement of the groundbreaking at 2.2lbs per indicated horsepower-hour, but at a boiler pressure of .
the compound engine was unusual at the time for a british vessel carnatic's boiler ran at only  higher pressures were not allowed by the board of trade the advantages of a compound engine were not fully realised at this low pressure - but the solution to the problem was to apply a large amount of superheat the efficiency gained was a fuel usage of just over 2lbs of coal per indicated horsepower-hour this is comparable to the achievement of the groundbreaking at 22lbs per indicated horsepower-hour but at a boiler pressure of 