In rail transport, distributed power (DP) is a generic term referring to the physical distribution—at intermediate points throughout the length of a train—of separate motive power groups. Such "groups" may be single units or multiple consists, and are remotely controlled from the leading locomotive. The practice allows locomotives to be placed anywhere within the length of a train when standard multiple-unit (MU) operation is impossible or impractical. DP can be achieved by wireless (RF connectivity) or wired (trainlined) means. Wired systems now provided by various suppliers use the cabling already extant throughout a train equipped with electronically controlled pneumatic brakes (ECP). History Since the 1960s, railroad distributed power technology has been dominated by one company, Harris Controls (originally Harris Corporation — Controls & Composition Division, later purchased by General Electric—the division now known as GE Transportation) who have manufactured and marketed a patented radio-control system with the trade-name of Locotrol, which is the predominant wireless DP system in use around the world today. With its origins in the early days of SCADA technology for the remote control of pipelines and electric utilities, and from an early concept of Southern Railway President D.W. Brosnan, Locotrol was a product of the North Electric Company (Galion, Ohio) which was later purchased by Radiation Inc. (Melbourne, Florida) and—in turn—purchased by Harris Corporation (also headquartered in Melbourne). The nascent technology was first tested on the Southern Railway in 1963, and the first production systems were installed on the Southern Railway in 1965. In the early years of this technology, WABCO also had—for a relatively brief period—a competing system called "RMU" (Remote Multiple Uniter), which was installed on a few North American railroads. However, this system did not prevail and soon went out of production. Prior to the advent by North Electric of the proprietary Locotrol name, the product was referred to as "RCE" (Radio Controlled Equipment) or "RCS" (Radio Control System) and the lead and remote units as "master" and "slave". The colloquial master and slave terms, though, were not formally used by the manufacturer. In some U.S. railroad parlance, Locotrol trains are referred to as "radio trains". Advantages and disadvantages The greatest benefit of distributed power—and the reason for development of the original concept—is the reduction of draw-gear draft forces, permitting a wholesale increase in the size of trains without exceeding draw-gear strength, through the use of mid- or end-of-train locomotives. There are also