From Sailors and Traders: A Maritime History of the Pacific Peoples, by Alastair Couper (U. Hawai‘i Press, 2009), pp. 141-142:
The companies secure within colonial territories made more capital investments in land, stores, and shipping. A major item was the shift from wind power to coal in propulsion and from wood to iron in ship construction. In many ways sail was still more suited to Pacific conditions. Distances were great—some 6,500 miles from San Francisco to Sydney. By then more information was available on favorable winds and currents for passage planning under sail, where calms had always been of more concern than storms. The early steamships, carrying around 1,500 tons of cargo, were disadvantaged, as they burned about thirty-five tons of coal per day to give a speed of seven knots. This meant coaling stations were required across the Pacific, including Honolulu (2,100 miles from San Francisco), Suva (2,800 miles from Honolulu), and to reach Sydney, another 1,700 miles away. Coal was expensive whereas wind was free. Bunkers took up cargo space and added weight, as did the engines, which required spares, skilled engineers, and technical maintenance. Coal in turn had to be brought to bunkering ports by other ships and stockpiled. By the 1870s there were bigger steamships with more efficient engines, requiring a coal consumption of fourteen tons per day at nine knots. Sail then focused internationally on low-value bulk but continued on some Pacific routes.
In the island trades the strategies adopted by several companies were to continue using sail for the long-haul supply ships from main ports, ultimately with auxiliary engines, and steam vessels for trading permanently around the islands, for a time with auxiliary sail. The advantages of steam and diesel propulsion in the islands included improved schedules, greater maneuverability in reef areas, ability to work clear from a lee shore, and the facility to leave lagoons regardless of wind direction. On Chong [Trading Company] employed the barque Loongana for the 2,500-mile passage from Sydney to the north Gilberts, and steam vessels such as the St. George for trading around the islands. It was such a successful division that when the Loongana was lost, she was replaced by the sailing ship Alexa, until she too was lost in 1924.