Before leaving this interesting subject of ocean oil transportation, I should like to emphasize the distinct step forward which is marked by these latest oil tankers. To-day, we have entered the era when oil fuel has passed its experimental stages and become one of the greatest boons to those associated with the navigation of the seas. The ease with which oil fuel is handled is remarkable, for vessels of the largest size—that is, those using oil instead of coal for power purposes—could replenish their stores within a few hours at any oil port. In the transport of petroleum by the modern tankers, the taking on board of a full cargo is accomplished in about a single day, thanks to the most improved means of pumping oil from the shore tanks through flexible pipes. The great oil tankers trading between this and other countries and Mexico, load up off the Mexican coast by means of a submarine pipe-line, and, reckoning but fourteen return trips per annum, it will easily be apparent what immense stores of petroleum can with ease be brought to the centres of consumption. Compare this with the primitive methods of transport in barrels, and it will be readily seen with what rapidity the hands of progress have moved during comparatively recent years.
The vast majority of oil tankers to-day, true to their calling, derive their power from oil, for they burn it under their furnaces, and, therefore, are not liable to those tedious delays so inseparable from the use of coal, and should severe storms beset their passage in Mid-Atlantic, then a little oil pumped overboard will quell the most turbulent sea and permit a safe passage onward.
It is evident, however, that the motor-engined oil tanker will be the order of the future, for already vessels are being built which utilize oil fuel internally—a much more economical process than burning it under boilers.
CHAPTER VI
PETROLEUM AS FUEL
So much has been written of late as to the use of petroleum as fuel for the purposes of steam-raising, that the reader is bound to be more or less au fait with the subject. It is, of course, one of vast importance, and during the next decade is certain to receive far more consideration than it has hitherto done, owing to the general desire that our coal wealth shall be conserved as much as possible. Given the one allowance that oil fuel can be procured at anything approaching a reasonable figure—and there is no reason why, in normal times, this reasonable price should not be prevalent all over the world—then petroleum offers many advantages over its older competitor, coal. The ease with which large quantities can be handled, the simple method of operating anything which is fired by petroleum as fuel, and the fact that its heat-giving units are far higher than those of coal, will ever be the chief factors governing its popularity.
Many years ago, fuel oil made its serious début, but at that time the supply of the product was very uncertain, and, consequently, progress in passing from the old to the new form of power-raising was slow. To-day, however, matters have materially changed. The crude oil output has been immeasurably increased, and many fields whose production of crude oil is essentially suited for fuel purposes have been opened up. In this respect, the oil-fields of Mexico have no parallel, and it is recorded that, once these fields are provided with adequate storage and transport facilities, they can easily supply the whole of the fuel oil necessary for the world, and at the same time have immense quantities to spare.
But, though the subject of petroleum as fuel has aroused much attention for some years, there is still an erroneous idea prevailing as to what really is fuel oil. A word or two on this question will, therefore, not be without interest. Fuel oil is that portion of crude oil which is incapable of giving off by the process of ordinary distillation those lighter products of petroleum known as motor spirit, illuminating oils, or lubricants. It is, in a word, the residue of distillation which is unsuitable for refining purposes. It represents a black, tarry liquid, and is, of course, minus those fractions that go to produce the refined products. Many there are who refer to crude oil as fuel oil, but this is a misnomer, though crude oil, in many instances, is utilized for the purposes of fuel. In this chapter, however, when I speak of fuel oil, I am referring not to the crude oil as it comes from the ground (and which has a comparatively low flash) but to the article of commerce, the residue of distillation, which is the real article—fuel oil.
The headway which fuel oil has made during the past few years has been remarkable, though it is safe to say that its general use is still in its infancy. In no matter what capacity it has been tried as a heating or steam-raising agent, it has proved itself capable of withstanding most successfully the most stringent tests, and has convinced all who have given the question serious consideration that it holds numerous advantages over coal, yet has no drawbacks. Perhaps the most recent impetus which has been given to the use of fuel oil is that following the introduction of it, and now its general adoption, throughout the units composing the British Navy. On land, however, it has for some years achieved marked distinction. Especially is this the case in regard to its use on locomotives, the United States railways alone consuming last year over 6,000,000 tons of fuel oil. In the realms of industry, fuel oil, too, is claiming the attention of those large industrial establishments, and to-day is largely used for creating intense heats, such as are necessary in hardening, annealing, melting and smelting, rivet heating, glass-melting, etc.
Let me first of all refer to the use of oil fuel for marine purposes. Fifteen years ago, its use was very strongly advocated by Sir Marcus Samuel, Bart., for marine purposes, and he approached the British Government in an endeavour to get it taken up. Matters moved very slowly, but eventually oil fuel was adopted, and Admiral Sir William Pakenham asserts that it was due to the unceasing efforts of Sir Marcus Samuel that the Admiralty vessels constructed during the war were oil burners. The largest of this new class of vessels is the Queen Elizabeth. Oil fuel is now largely used in place of coal on our great liners, vessels like the Aquatania and Olympic having gone over to its general use.
There are, of course, many reasons which have commended fuel oil to the experts as a substitute for coal. In the first place, inasmuch as one ton of fuel oil is equal to more than one-and-a-half tons of coal, the radius of action of units fitted for utilizing fuel oil is increased over 50 per cent.—I speak from the point of view of bunker weight. Again, one ton of oil occupies considerably less space than an equivalent weight of coal, while this advantage can be materially increased—as is now the usual practice—by carrying the fuel oil in double-bottom tanks. Then the bunkering question is one of vital moment. Fuel oil can be taken on board under far cleaner conditions, and at a greatly accelerated rate, than would be possible with coal. There is no arduous manual labour required. Once the hose connections have been made, the fuel oil is pumped on board at the rate of hundreds of tons an hour, and a few hours suffice to re-fuel our largest battleship. But it is when bunkering at sea is required that fuel oil further emphasizes its immense advantages. This question was some years ago one of the problems of naval strategy: to-day it is regularly carried out in the simplest possible fashion, hose connections to a standing-by oil tanker being all that is required.