In a 5,000-ton D. W. ship, 16 engineers are required for coal and 12 for oil ; in an 11,000-ton ship, 27 and 18 men are required respectively.
The Shipping Board fleet of steamers is composed of ap proximately 10 million deadweight tons, of which 8 million tons are oil-fired. The Shipping Board has established bunkering sta tions at St. Thomas, Rio Janeiro, St. Vincent, Bermuda, the Azores, Brest, Dizerta, Constantinople, Colombo, Singapore, Manila, Shanghai, Durban, Sidney, Wellington, Honolulu and Panama.
The Tide Water Oil Company in "Fuel Oil" gives the follow ing data from a report to the Naval Advisory Board : "A 5,000 ton deadweight coal burning ship, 2,000 rated H. P., steaming at 12 knots per hour, will require approximately 37 days' time and 1,060 tons of coal to make a round trip between New York and French channel ports. This shows that 21 percent of the ship's deadweight capacity would be required by her fuel. The same ship burning oil could make the trip in 34 days, and requiring only 584 tons of oil, or less than 12 percent of the ship's dead weight capacity for fuel. Thus an oil-burning ship's cargo capacity is increased 9 percent or 468 tons per voyage. By storing the oil in double bottoms, which is standard practice, a 5,000-ton deadweight capacity ship can carry 689 tons, or 27 per cent more general cargo per trip, than a coal-burning ship of equal deadweight. The speed of a 5,000-ton boat in continuous service has been increased 10 percent by changing its fuel to oil. This is largely due to steady steam and increased boiler capacity affording maximum and constant propeller speed. Hence, a further 10 percent of cargo goes to the credit of oil-burning ships during their steaming time only, all of which is a net gain The cost of handling oil fuel is about 70 percent less than that of coal, owing to the fact that the oil is handled mechanically and the ash handling is entirely eliminated. The fire-room crew is materially reduced, generally by one-half to two-thirds of the crew necessary for coal firing. Efficiencies of boilers are in creased by 8 to 10 percent and steaming capacities from 35 to 50 percent, which is due to more rapid and perfect combustion obtainable. All of the foregoing saving features figure materially
in the dollars and cents column." "Coaling Ship" has always been regarded as a most arduous duty (see fig. 56). Ships of the "Wyoming" class in the navy carry as much 3,000 tons of coal, which is lifted aboard by large electric and steam winches after large bags have been filled in the lighters or colliers. Coaling a ship is usually an all-day job and an "all hands" detail, whereas fueling on an oil burner is both clean and speedy.' Fig. 57 shows the method of fueling with oil, and Fig. 58 shows a fueling station in the Orient.
Although oil had been successfully used under ship's boilers for a long time prior to 1904, it was the favorable report of the U. S. Naval "Liquid Fuel" Board in that year which gave a de cided impetus to the use of fuel oil on the sea. The investigation of this Board was conducted with such scientific accuracy and its report was so comprehensive that the Board's findings still are regarded as irrefutable. The Board made an extended series of tests for the purpose of determining the relative value of coal and liquid fuel for naval purposes and, in addition, it made a careful study of the performance of the S. S. Mariposa of the Oceanic Steamship Company and of the S. S. Nebraskan of the American-Hawaiian Steamship Company, both vessels being fitted for oil burning. Table 15 gives the comparative performances of the Ocean Steamship "Mariposa" using oil as fuel.
It is interesting to compare the test of the Mariposa with tests of the 8,800-ton steel steamer West Conob. The report of the Conob's test was submitted to the author by Mr. C. W. Geiger and covers the six hours' builder's trial off San Pedro, California, on May 20, 1919. On this trial trip the West Conob's three boilers were under steam pressure of 200 lbs. The temperature of the oil to burners was 205 degrees, and that of the stack 460 to 475 degrees. The temperature of boiler feed water was 200 to 215 degrees. An average of 411.1 gallons of oil was consumed per hour.