| Coal | 5 days | 500 men |
| Oil | 12 hours | 12 men |
The labour of stoking and clearing the furnaces is done away with; there is no longer either dust or smoke. Parts of the ship which are too restricted or too inconveniently placed for housing coal can be used for oil. It is stored in the double bottom of the boat, and by utilizing the coal bunkers for general cargo the available storage space is increased by 10 per cent. On the latest Cunard and White Star liners the economy of space thus realized has been as much as 33 per cent. And Admiral Lord Fisher drew attention to the fact that on the Mauretania—the sister ship to the Lusitania—the adoption of oil fuel allowed of the reduction of the crew by three hundred men.
The efficiency of a boiler heated by coal is not much more than 60 per cent.; that of one heated by oil reaches 80 per cent. On Japanese steamers of the type of the Temyo Maru, of 21,000 tons, with Parsons turbines of 20,000 horse-power, the consumption of oil is only 455 grammes to one effective horse-power, instead of 685 grammes of coal. The flexibility and ease of control are extraordinary.
Since 1911 the merchant fleet of the United States has been consuming 15 million barrels annually. Nearly all the nations have followed this example,[3] especially those which dream of the dominion of the seas for the use of oil in their warships gives them an incontestable superiority. The presence of a squadron sailing under coal is disclosed at a distance of more than 10 kilometres by enormous clouds of smoke; under oil its presence is almost imperceptible; it becomes visible only at the moment when it is about to attack. Ease of approach is enormously increased; and even if an enemy vessel is discovered by marine or aerial scouts it is very difficult for the gunners of the threatened vessel to take their aim at so vague a target as an almost invisible horizontal silhouette. "No smoke, not even a funnel!" exclaimed Lord Fisher in his strenuous campaign for the transformation of the British Navy. Many years elapsed, however, before he saw the triumph of the new fuel.
It has been objected that ships lose a little of the protection which is conferred upon them by their belts of coal bunkers; but this criticism is valueless. For, as they gain considerably in lightness, it is possible to increase the thickness of the armour plate and the size of the guns. The abolition of funnels permits of a considerable increase in the field of fire of the artillery.
Moreover, with oil fuel fleets acquire an extreme mobility.[4] Half an hour after receiving the order to raise steam the ship is ready to start. Thirty-five minutes afterwards it is going at full speed. In six minutes it can pass from normal to maximum speed. Eleven minutes are needed to get a boiler under full pressure. A voyage at forced speed entails no extra fatigue for the crew: with coal it is hell!
Thus, since 1912, oil has been constantly used on twenty-eight German battleships, almost the whole of the fleets of Great Britain and the United States, and the Russian squadrons in the Baltic and the Black Sea. The American Navy has completely abandoned coal for its new units.
And France? France, which was the first to conceive the idea, had, at the moment when war broke out, only a few small boats burning oil, and not a single powerful modern vessel comparable with the Queen Elizabeth. And yet, as early as 1864, it was France that built the first ship, the Puebla, sailing under Lieutenant Farcy, to use the new fuel, which aroused so much curiosity during the Second Empire. But the selfish opposition of our coal-owners overcame those who were favourably inclined, including Napoleon III himself.
No one gives a thought to these facts at the present time. France often points the way of progress; she never profits by it.