Abridgment of interconnection and power development in Chicago and the Middle West

The development of power stations in the Chicago District is described, showing how small stations have been replaced, and the energy supply for light, power, and traction consolidated by the use of high-voltage lines. The interconnections between stations and the developments of recent years and for the immediate future are outlined. This includes cables at 66,000 and 132,000 volts, with circuit capacities of 60,000 kv-a. A station in Central Illinois, near the coal supply, is being tied in with the Chicago District. Interchange of energy between companies is conducted under an agreement, which is an important factor in the success of interconnection. Some of the operating problems are outlined briefly.