the train engine is built with that angle in it so as its climbing the mountain, the water keeps the boiler tubes covered with water. Train stops just short of halfway up and takes on more water for steepest part of mountain 37* grade up ahead to be sure boiler tubes are covered. Engine burns about 1> 1.5 tons coal ascending the mountain. About a hour ride up. Not going fast at all, slow and steady. Engine stays as where its located to passenger car, brakes on pass car, plus engine uses its drive pistons, compression of air to control descent. they are not directly coupled together. pushes car up, engine is its oown brake, passenger car is pushing ever so lightly to barely touching, on engine as they descend mountain.