 The next landmark on the railroad past Pigpen Siding was Horseshoe Curve, a sharp curve in the shape of a horseshoe near the adjacent treeline, which was fashioned after the Pennsylvania Railroad's Horseshoe Curve near Altoona, Pennsylvania, and which restricted trains to 8 mph (13 km/hr).After leaving Horseshoe Curve, a second, lesser-used, siding was encountered, after which the line curved to the right and the Long Fill (about a five-foot (1.7 m) fill) where the best speed on the railroad could be made.