NEW ORLEANS CITY AND LAKE R. R. Co., MR. T. C. PENINGTON, SECRETARY, AMERICAN STREET RAILWAY ASSOCIATION, Dear Sir:-I beg to say, with much regret, that, owing to business conditions, I will be unable to attend the Street Railway Convention and read the paper which I have prepared. Wishing every success for the pleasure and interest of the members, I remain, Yours very truly, BENJ. WILLARD. WORCESTER CONSOLIDATED ST. RY. Co., THOS. C. PENINGTON, ESQ., SECRETARY, AMERICAN STREET RAILWAY ASSOCIATION, My Dear Sir:-I regret that I am unable to attend the Convention, as we have work to do that requires my presence at home. I sent a copy of the paper I prepared on the subject of "Trucks" to you some time ago, and presume you can have the same read, if you deem it worthy of such consideration. Thanking you in advance for any courtesy you may extend me in the matter, I remain, Respectfully yours, JOHN N. AKARMAN. The President: The first paper on our list is that by Mr. M. K. Bowen, Superintendent, Chicago City Railway Company, on "Tracks and Track Joints, Construction, Maintenance and Bonding." REPORT OF THE COMMITTEE ON "TRACKS AND TRACK JOINTS CONSTRUCTION, MAINTENANCE AND BONDING." Mr. Bowen read the report, as follows: I. TO THE AMERICAN STREET RAILWAY ASSOCIATION, Gentlemen:-After signing a contract to tell my associates in business how to construct and maintain a street railway track, I began to cast around for data bearing upon the subject, and found that the life of a rail was measured by the wearing out of the head, and less than twelve per cent. was worn away before we sold the old rail for scrap; hence the deduction, that the point of contact between the wheel and the rail, in other words, the bearing and wearing part of the track, was the most important consideration. I asked a wheel manufacturer why wheels of street railroad cars were made conical or bevel-shape instead of flat. His answer was "To draw out of the mold, of course." Not being satisfied, I asked a steam railroad man the same question. He said "It is for the purpose of compensating on curves for the farther travel of the outside wheel." If I had asked a street railroad man the same question he would have promptly and correctly answered (even if he did not know and had to guess), that the bevel on a car wheel was for the purpose of centering the car on the track, providing a means for a lagging wheel to catch up again, and maintaining the axles of the car at right angles with the rail of track. The foundry man was wrong, because we all know that flat wheels can be made. The steam railroad man when he answered, had in mind his 10 degrees maximum curve, but in applying his answer to our conditions he was wrong, because on a quarter-circle curve of 50 feet radius, 30-inch wheels, the outside wheel is compelled to travel 7 feet 434 inches farther than the inside wheel, and the absurdity of the bevel of 4 inch on a 2-inch tread compensating for this travel, and preventing slipping, is readily apparent, as it would require a bevel of 11 inches in a 2-inch tread to compensate for the difference in travel of the wheels. The effect of the slipping of wheels on curves is clearly shown by the brightness of the rails, which show abnormal wear. The street railroad man was right, because if he stands behind any of his receding cars he notices the movement of the car from side to side with a rythmic motion which tells of an action taking place. The analysis of the action develops a coal-saving, wear-saving movement, always at work; a sort of a silent partner, producing part of your dividend, for if this motion did not exist, the wheel which once got behind, and the axle which once assumed a position not at right angles with the truck, would be apt to remain in its faulty position during the entire trip, requiring excess of power to haul the car, and abnormal wear of wheel and rail, resulting in sharp flange wheels and short life of rail. II. The action taking place is this: Suppose the car has shifted toward the rail y y', Fig. 1. This action causes the wheel (a) to bear upon its smallest diameter, and the wheel (b) to bear upon its greatest diameter, with the result that (b) runs ahead of (a). This brings the axle at an angle with the rails, as shown by (a') (b'). The wheels will now tend to shift to the opposite side-x x'—the wheel (a) will rest upon its largest diameter, while the wheel (b) will rest upon the smallest diameter, when (a') will start and run ahead of (b'), bringing the axle into position shown by (a") (b"), and this action keeps up continually, tending always to keep the truck in the center of the track. If the wheels had no bevel, the result would be that unless the rails were exactly on the same level the car would shift to one side-the effect of which you all know. III. Take first a conical wheel running on a rail the surface of which is level. a FIG. 2. Referring to Fig. 2, we note that the rail and wheel make contact only at the point shown at (a). This is the state of affairs when the rail and wheel are new. In a few months, if we again examine our wheel and rail, we will not find them the same as when we first looked at them. We now observe that the wheel is badly worn next to the flange, while the inner edge of the head of the rail has flattened to a considerable extent and worn down. Both the wheel and the rail are doing their best to come to a common bearing surface, but it is at the expense of scrap wheels, of which only half of the tread has been worn through the chill. It is quite plain that the rate of wear must be enormous at first, for the whole weight of the car is brought to bear upon a very small surface (a-Fig. 2,) almost a point, I might say. This rate of wear steadily de creases as the surface of the rails and wheels wear themselves away until the contact between the two is a line the whole width of the rail, and not merely a point. But long before the surface of the rail has conformed to the surface of the wheel tread, where the best form is attained, the head of the rail has lost a large percentage of the metal allowed for wear, and as wheels wear faster than the rails, it has taken in some cases thousands of quickly worn out wheels to bring the rail to its final and best form. FIG. 3. Figs. 3 and 4 show sections of the rail now in use on the State Street cable line, the height of the head being 1,3 inches. The first rail put in on State Street, Chicago, had a head 4 inch high. This was increased to 1 inch and later to 1 inches. It is beveled to conform with the bevel of the car wheel for two-thirds of its section from guage line across the head. Many will ask, no doubt, if there is not a slipping of the wheels on the rails, due to the unequal diameter of the wheel at all points? There is, if we imagine the wheel divided into three parts at rightangles to its axis (Fig. 3), and each piece free to move by itself, and whose diameters are situated at a, b, and c, respectively; and it is quite evident that as the portion (a) makes one revolution it will travel over a less distance than the portion (b) would, and similarly the portion (c) will travel farther than the portion (¿) in one revolution, but on account of it being all one, the portion (a) travels farther than it otherwise |
