OIL BURNING LOCOMOTIVES.
The first successful operation of oil burning loco motives was on the Griazi-Tsaritzin Railway, in Rus sia. Thomas Urquhart, who was superintendent of motive power, converted some of the coal-burning locomotives to oil burners in 1882. Several reports have been published showing comparisons between the performances of these locomotives before and after this change was made. The calorific value of the oil was 18,600 B.t.u., and the coal used was Russian an thracite, very similar to Cardiff coal, having 14,000 B.t.u. One pound of oil was found to be equivalent to 1.78 lb. of coal.
In a discussion before the Institute of Mechanical Engineers in 1899, Mr. Urquhart stated that the high est actual evaporation obtained was 14 lb. of water per lb. of oil, at 125 lb. steam pressure, from 60 deg. This would be equivalent to 16.8 lb. from and at 212 deg. The average evaporation was 12.5 lb. of water per lb. of oil. These fine results were obtained in spite of a handicap imposed by the Russian govern ment, which would not allow the railway company to adopt fuel oil unless they proved that the fire-box could be changed at a moment's notice to burn coal.
As a comparison between the two fuels, the fol lowing report is given. This should be compared with the reports from other railways given elsewhere: To illustrate the great improvements in the de sign of oil-burning locomotives made in recent years, it will be interesting (for comparison), to examine some of the earlier models. Fig. 60 shows the details of arch, ash-pan, and position of burner and brick work as used by the Santa Fe Railroad. When first changing from coal to oil, it was necessary to remove the grates and bearing bar, and to fit a pan below, riveted to the sides. This pan acted as a bearing for the necessary brickwork, and was arranged to allow the air for combustion to pass through the brick work. The fire-box arch was built in front of the flues, thus protecting them from the flame. The burner was placed at an angle, to allow the flame to strike below the arch.
The regular coal and water tenders were used by placing a specially constructed oil tank into the coal compartment. A large rectangular tank with a com bined capacity of over eight tons of oil, was placed over the top, securely anchored to the tank frame.
The oil was heated by means of a heater coil. This was necessary because of the low gravity of oil used at times.
Fig. 61 shows the details of these early converted tenders as used on the Santa Fe railroad. The cost of converting these old locomotives and tenders aver aged about $350 each.
The improvements of recent years have abolished the arch setting, as shown in Fig. 62; this also elimi nates the combustion chamber. The burner is re versed, and placed at the front end of the fire-box, which is lined with fire-brick about 2% in. thick on all sides except the back, where the wall is 18 in. thick. The air for combustion enters at the bottom, and the admission is regulated by means of a damper. It is led under a layer of fire-brick to the burner, being heated by coming in contact with the hot brick. The natural sweep of the gases carries them to the back end of the fire-box, where they strike the heavy fire-brick wall and turn back and up through the flues. The cost of maintenance is considerably low ered by this arrangement, as the flame does not strike on the tube sheet and the expense of rebuilding the arch is eliminated.
Fig. 63 illustrates in detail the semi-cylindrical tender and tank for oil burning locomotives used by the Southern Pacific Company. The tank is divided into oil and water compartments, the former of 3300 gallons, the latter of 7300 gallons capacity. The length outside is 28 ft. 6 in., width 9 ft. 4 in., height 6 ft. 5 in., these being measurements on the tank proper. The radius of curvature of the top is 4 ft. 8 in.; the lower part of the sides are straight. The tank is con structed of in. steel, with lap seams, single riveted with in. rivets at 2 in. pitch. Manhole rings, and the plate for the oil compartment, are of cast iron, with openings 16 in. in diameter. The cover is slightly convex in form, and is held in place by three bolts having hand-wheel heads for easy removal. The opening is provided with a six mesh strainer, 22 in. deep, and tapering to 6 in. at the bottom. The interior of the compartment is provided with lateral and inter secting splash plates, and with a steam coil of 1 in.