The Steam Packet Company paid £112,000 for Ben-my-Chree, but high speed cost roughly one hundred tons of coal per day. Estimates vary slightly with route and operating conditions, with one calculation putting daily consumption at 97 tons. The civilian operator economized by buying good coal rather than the finest Welsh grades procured for Royal Navy warships. Better fuel, naval machinery tuning, and crews willing to push the ship in wartime may help explain performance above her official rating. Coal quality was part of operational capability as well as a procurement expense.
Notable Point · 24:56-26:19
Coal quality links operating cost to wartime speed
Ben-my-Chree's heavy coal demand made speed expensive, while the Royal Navy's higher-grade fuel may have helped her exceed the civilian and official naval figures.