If it is necessary to examine bunkers, effect repairs, etc., the fuel oil can be pumped out in a very short time ; either into the other fuel tanks or into a tank alongside, instead of the very slow and tedious business of dis charging coal to various tortuous passages into lighters alongside. The oil can be discharged in a less number of hours than the coal would take in days, and probably by two men ; whereas with coals it would entail the whole staff.
In regard to bunkering, 7,000 tons of fuel oil can be stowed in a ship's tanks in six hours—the same quantity of coal would take forty-six hours, most of the staff being employed, at the rate of, roughly, 150 tons an hour. In short, oil-fired boilers spell greater efficiency, comfort, cleanliness, and economy.
Experience has shown that it entails less labour to attend to twelve or more oil fires than when attending to three coal-burning furnaces. The time necessary for the changing of a burner is less than GO seconds, while the cleaning of the cones involves nothing more than rubbing over the edge of the cone with a small scraper, and is done at regular periods to ensure a regularity of attention to each furnace. A well-known authority informed me that in the average oil-fired job, having only one stokehold, one man only is nece4sary to attend to the burners and fires, and a number of vessels are operating with one man attending fifteen fires. Another well-known expert stated that he had nut a five days' hard trial on a naval boiler without cleaning a burner or without dismounting one, and the air cones and furnaces were as free from carbon or blemish of any kind as at the start.
With a proper arrangement, every furnace and every burner should be able to range from the condition of banked fires to full power without altering a burner or making a change of any kind save a regulation of the burner and a regulation of the supply of air. It is
obvious to anyone who has been in the stokehold of an oil-fired ship during running, that the work is by no means of an arduous description. It is also a well known fact that, once a man has served as a fireman in a vessel run by oil, he greatly dislikes returning to work in a coal-firea ship.
NVith coal-fired boilers there is always a considerable loss of steam every watch, through burning down and cleaning of fires. Take, for instance, the serious loss to a vessel of the Aquitania class, which has no fewer than 168 furnaces. Assuming that twenty-eight fires are cleaned every watch, approximately 8,000 h.p. is lost every four hours. With oil-fired boilers no such loss is incurred, as the oil can be supplied continuously to the burners, and the heating maintained so that a constant steam pressure can be kept up. The result of equipping her with oil fuel installations has had the effect of improving the speed of the vessel. The original contract speed under coal was 23.50 knots. In making a recent return journey from America to this country, an average speed of 23.45 knots was maintained, while over a run of 129 miles she attained the maximum speed of 27.40 knots.
The bunkering with oil of this huge ship was effected at the rate of 480 tons an hour, while the Olympic can readily take in sufficient oil in six hours to carry her over the round trip. Only three men arc required to carry out the entire operation. Before being fitted for oil burning, the time taken to bunker these vessels with coal was about 108 hours at each end, and for this work between fifty and sixty men were employed.