EXPERIMENTS OF TRAIN RESISTANCES ON THE ERIE RAILWAY.
In experiments made with a freight train on the Erie Railway in 1881, reported by Mr. F. M. Wilder to the Railway Master Mechanics’ Association, it was found that the total resistance on a level track was from 3.25 to 4.5 pounds per ton at speeds under twenty miles an hour. These figures will approximately represent the resistance due to wheel and axial friction in summer; but this resistance will be higher during cold weather, when the oil in the axle-boxes gets frozen. Track in bad condition will also tend to increase the wheel resistance, and improperly constructed trucks and wheels will entail the use of more power to move the train. Where trucks are so defective that they do not maintain the wheels revolving in parallel planes, the flanges of some of the wheels will rub on the rail, increasing the resistance. Wheels out of round; those having the axle out of center, however slight; wheels of different size on the same axle; and numerous other car-truck disorders,—all contribute their share in making a train pull hard.