Comfort on Sharp Curves - In 1889, the sophisticated resort of Langenschwalbach – today Bad Schwalbach – received a rail connection. The line to Wiesbaden had grades of around 3.3% as well as curve radii of a minimum of 200 meters / 656 feet. The Prussian State Railways has passenger cars of a new type built just for this curving right-of-way. Unlike the usual commuter service passenger car designs of that time with almost always two or three rigidly mounted axles, the Langenschwalbach cars were equipped with two-axle trucks. This design turned out so well that they were built from 1892 on for almost 35 years without changes.