The use of oil fuel has also been varyingly adopted on railways in France, Italy, Russia, Rumania, India, Egypt, Mexico, Japan, and on several lines in different South American Republics. In the majority of those countries petroleum is produced in large quantities, and the crude oil yields a good percentage of fuel oil. They arc thus able to rely on continuous supplies. It may be interesting to state that, during the war, Egypt was saved from a fuel famine by the possession of an indigenous oil supply, which had been developed so successfully during the few previous years.
Another country where railways arc practically wholly run on fuel oil is Mexico. As will have been observed from the record of production on page 7, Mexico possesses enormous supplies of fuel oil ; the crude yielding a very high percentage of residue oil, suitable for power purposes. The quantities of oil consumed on these railways for each year from 1916 to 1918 were as under (1-1,000 barrels)— Interesting tests were carried out on Mexican loco motives, two different types of burners being used. The results of these tests are important as showing the working of the two oil fuel systems, one of which was a pressure system, the other in which steam was used for atomizing the oil.
The line in question is characterized by many steep gradients, in one instance, at least, the rise being 1 in 25. It is in work of this trying description that oil fuel reveals its superiority, the requisite amount of additional power being secured in the most economical manner. On the National Railways of Mexico the cost of oil fuel a train mile worked out at 5d. as compared with a cost of 7d. a train mile for coal.
The Southern Pacific Railroad, a South American line, converted many of its locomotives to oil a few years ago, and records are available concerning the portion of the track which crosses the Sierras Nevadan. The engine employed was a 10-wheel engine, and the train ?n this instance consisted of seven cars.
The oil used during this run was Kern River (California) oil of heavy quality, having a specific gravity of 15•8 Baume (.9G) and a flash point of 230° F.
Among the British Railway Co.'s which have initiated the movement towards the employment of oil for running their engines arc the London and North Western, the Great Central, the Highland of Scotland, the Lancashire and Yorkshire, and in other parts of the Empire India leads the way, the North Western (State) Railway having recently converted several of its locomotives to oil burning. These engines were origin ally fired with coal, and have been adapted to oil fuel by arranging a brick arch in the fire box to distribute the flame. The consumption of fuel oil over a period of six months showed that one ton of oil equals 1.85 tons of coal by weight. The descriptions of fuel used are given by the Government Test House at Alipore as follows— The calorific value of the oil was 58 per cent better than that of coal, while in actual consumption a day it was no less than 85 per cent better.
The locomotive superintendent of this railway stated in his report that brass tubes had not been found satisfactory for oil burning engines, as the nuts and ferrules burnt away quickly, an action which was undoubtedly due to the very high percentage of sulphur in the oil used. In fact, I am unaware of an oil with
so high a content of sulphur. He also contended that engines burning oil fuel require more staff and more thorough attention than coal burning engines, as the oil burning arrangements must be kept tuned up. I do not know what description of oil fuel burner was employed on this railway, but the statements made do not conform to practice in this country. If it is intended to convey that an oil burner needs more care than is given to merely shovelling co.ds on a fire, then his contention is correct.
This report also states that projections in the fire box, such as nuts or rough edges, the fire hole ring, etc., where friction is likely to occur, soon get burnt away by the intense heat of the oil flame. It is, of course, essential, as the locomotive superintendent remarks, that as equable a distribution of the intense heat generated is secured as possible, which is, of course, a matter the constructional engineer would certainly have in mind, in equipping the engine with oil burning appliances and arranging the interior of the furnace.
The Scarab oil burning system which was used extensively in Egypt during the war has also been fitted to locomotives on the railways in Portugal, Mesopotamia, Sudan, and South America. With this system adopted by the London and North Western Railway for its first main line express locomotive over a distance of 113 nules, and hauling a weight of 294 tons, the con sumption of oil was 10.S3 lbs. for 100 ton miles, and 32 lbs. or 165 galls. a mile an hour. The Scarab Company claim that with their system 42 lbs. of fuel oil will haul a train a distance which, with coal, would necessitate a consumption of 100 lbs. of coal. The Ceylon Government is also following the growing practice and is converting several of its locomotives to oil burners The table on page 60 will be of interest as showing the great fuel economy obtainable in oil over coal for locomot ivies.
Although these figures arc not the most recent, they are sufficiently approximate to illustrate the point desired.
In concluding this section, it may not be inappropriate to reproduce a statement made by Sir Janu, Holden on the question of fitting a locomotive with oil fuel burners.
The most desirable position of the burners, he remarks, could only be arrived at by long continued experiments, and so far the best results have been obtained with the burner eccentric to the holes in the fire-box. This setting of the burners conduces to economy of steam at the ring blower jets, as it utilizes the steam to its utmost for an induction. The ring blower attached to the burner is arranged eccentrically to the nozzle, and the brick axle, usually provided on coal-burning engines, is retained to obviate the too-direct passage of products of combustion to the tubes, and to ensure thorough combustion. The fire-door, in this design, is provided with a deflector to direct downwards into the centre of the fire any air admitted to the fire door. Thus all the features necessary to the successful burning of solid fuel are retained.