For example, the Chicago City Railway, also designed by Eppelsheimer, opened in Chicago in 1882 and went on to become the largest and most profitable cable car system. As with many cities, the problem in flat Chicago was not one of incline, but of transportation capacity. This caused a different approach to the combination of grip car and trailer. Rather than using a grip car and single trailer, as many cities did, or combining the grip and trailer into a single car, like San Francisco's "California Cars", Chicago used grip cars to pull trains of up to three trailers.