Appendix E CHRONOLOGY OF TRAIN CONTROL DEVELOPMENT The history of train control technology in rail 1832 The first fixed signal system in America rapid transit is interwoven with railroad engineer- was installed on the New Castle & ing. Most of the train control techniques applied in Frenchtown RR, The signals were ball- rail rapid transit have their origin in railroading, shaped objects mounted on masts at 3- from which they are either borrowed directly or mile intervals. The signals were raised adapted to the special circumstances of the urban and lowered by a signalman to indicate setting. For this reason, many train control permissible speed—low meaning stop engineers consider ATC in rail rapid transit simply and stay and high meaning proceed at an extension of the field of railroad signaling. full speed, The latter indication gave rise However, there are some distinct differences, both to the expression “highballing.” in the technology and its application. The 1843 The first mechanical interlocking was similarities and differences are evident in the installed at Bricklayer’s Arms Junction in chronology of train control development presented England. It was a simple machine oper- here. ated by a signalman who worked the The development of signaling and train control switches with his hands and the signals technology may be separated into two periods, with with his feet. 1920 as the dividing point. Before 1920 the major 1851 Morse code electric telegraph was first areas of technological advance were interlocking used in train operation for sending train control and block signaling (manual and automatic). orders on the New York & Erie RR. After 1920, the demand for moving heavier traffic at higher speeds and with increased safety led to 1853 The Philadelphia & Reading RR installed major developments such as centralized traffic con- signal towers for giving information to trol, continuous cab signaling, coded track circuits, approaching trains on the occupancy of and automatic train control. Generally, innovative the track in advance. signaling and train control technology for rail rapid 1853 Open-circuit manual block signaling was transit was derived from railroads and lagged first used in England. behind railroad application by about 10 years. There were some notable exceptions; the development of 1860 Gate signals were initiated in America. automatic junction operation and automatic train A stop indication was displayed by plac- dispatching was pioneered in rail rapid transit. Very ing a red banner or disc on top of the gate recently, since roughly 1960, there has been some during the day. A red light was displayed experimentation with techniques and equipment at night. solely for rail rapid transit and small people-mover systems. 1863 Closed-circuit (fail-safe) manual block signaling, using the space interval The major source of this material is American method of operation, was first employed Railway Signaling Principles and Practices, in America on the United New Jersey Chapter l—History and Development of Railway Canal & RR Co. between Kensington, Pa. Signaling, published by the Association of (Philadelphia), and Trenton, N.J. American Railroads, Signal Section, 1954. Supple- mentary information, particularly on rail rapid tran- 1866 The first automatic electric block system sit technology in recent years, was assembled from was installed on the New Haven System various sources, including manufacturer’s at Meriden, Corm. Hall enclosed disc sig- brochures, local transit agency reports, and techni- nals, open circuit, were operated by track cal journals. instruments. 215 1868 The Pennsylvania RR used a type of trains was in use on the New York, New train order signal which was under the Haven & Hartford RR and the New York control of the train dispatcher who could Central & Hudson River RR. When oper- set it in the stop-danger position at any ated automatically by a treadle device on remote station by means of a selective the rail, the passing train released a device operated over the regular Morse pointer which started to move around a telegraph circuit. dial divided into three segments each representing 5 minutes. The pointer 1870 The first interlocking machine in movement was controlled by an escape- America was installed at Top-of-the- ment so that it moved across the dial in a Hill, a junction at Trenton, N. J., on the period of 15 minutes. Headway for the Camden and Amboy Division of the train ahead was thus indicated up to 15 Pennsylvania RR. minutes. 1871 A system of automatic block signals, 1885 The first electric detector locking for in- comparable with presently used equip- terlocked track switches was installed by ment, was installed on the New York & the Pennsylvania RR at the Pittsburgh, Harlem RR and the Eastern RR. Pa., terminal by using depression trips to 1872 The first installation of closed d.c. track ground the indication circuit. circuit, invented by Dr. William Robin- son, was made at Kinzua, Pa., on the 1889 The first electric interlocking employing Philadelphia & Erie RR. dynamic indication, invented by John D. Taylor, was installed at East Norwood, 1873 The Robinson closed-circuit track block Ohio, at the crossing of the Baltimore & for switch protection was first put into Ohio Southwestern RR and the Cincin- use on the Philadelphia & Erie RR. nati and Northern RR. 1876 The first power interlocking of the Burn 1893 The first low-voltage, direct-current, pneumatic type was put in use on the motor-operated automatic semaphore Pennsylvania RR at Mantua “Y,” West block signals were installed on the Philadelphia, Pa. Central RR of New Jersey in Black Dan’s 1876 The Boston & Lowell and the Boston & Cut, east of Phillipsburg, N.J. They were Providence RRs introduced the Robin- two-position lower-quandrant signals son electromechanical signal for with the motor and driving chain outside automatic blocking, controlled by direct the mast. current track circuits. 1900 The first three-block indication was in- 1880 The first automatic train stop was placed stalled on the Pennsylvania RR between in trial service on the Middle Division of Altoona and Cresson, Pa. The signals the Pennsylvania RR. A glass tube in the were two-position, lower-quadrant, train air line located on the locomotive home and distant automatic semaphores, near the rails was designed to be broken by a “track trip” set in operating position 1900 In Acton Town, England, an illuminated when the signals were in the stop posi- track diagram was first used in connec- tion. tion with resignaling on the District Ry. due to electrification, It dispensed with 1881 The first interlocking of the hydraulic separate track indicators and brought type was installed by the Union Switch & together all track occupancy information Signal Co. at Wellington, Ohio, for a on the plan of tracks and signals, thereby crossing of the Wheeling & Lake Erie Ry. facilitating the work of the signalman with the Cleveland, Cincinnati, Chicago handling traffic. & St. Louis Ry. 1901 The Taylor Signal Co. put in service the 1885 The “Dutch Clock” device for establish- first electric interlocking embodying the ing time intervals (headways) between “dynamic indication” principle, at Eau 216 Claire, Wis., on the Chicago, St. Paul, 1912 Cab signals were first used on an electric Minneapolis & Omaha Ry. railway, the Indianapolis & Cincinnati Traction Co. ● 1901 The Boston Elevated installed special 1914 polarized d.c. track relays. This was the The cam controller for control of power first attempt to operate track circuits on a application to d.c. propulsion motors was railroad where propulsion power was first used in the Chicago Rapid Transit supplied by electricity and the rails were co. used as the medium for current return. 1915 The American Railway Association adopted rules which permitted train 1901 The Boston Elevated made the first per- operation on single track by controlled manent installation of an automatic train manual block signal indications, super- stop system, which consisted of seding timetable and train orders. mechanical wayside trips engaging brake control apparatus on the moving car. 1919 The Buffalo, Rochester & Pittsburgh Ry. made the first trial installation of the 1903 The North Shore RR of California made General Railway Signal Co. intermittent the first installation of a.c. track circuits inductive train stop system. This system for automatic block signals. used magnetic induction to transfer sig- nals from wayside controls to train 1906 The first signal system with a.c. track equipment. circuits on a road using a.c. propulsion 1920 The first installation of automatic speed power was installed on the New York, control in the US. was that of the Regan New Haven & Hartford RR, The track Safety Device Co. intermittent electrical circuits were the two-rail type, 60 Hz, contact ramp-type train control system with impedance bonds. Propulsion cur- on the Chicago, Rock Island & Pacific RR rent was 25 Hz. between Blue Island and Joliet, Ill. 1907 The first automatic interlocking for the 1923 The Pennsylvania RR placed in service, protection of a railroad crossing was in- experimentally, the first installation stalled at Chester, Va., at a crossing of anywhere of the continuous inductive cab the Tidewater & Western Ry. with the signal and train control system coveting Virginia Railway, Power & Light Co. 43.5 miles of single track and 3.4 miles of two-track, between Lewistown and Sun- 1909 The Erie RR installed automatic signal- bury, Pa. It was the first instance where ing for train operation by signal indica- vacuum tubes were used for purposes tion on a two-track division, 139.7 miles other than in communication circuits. in length, which directed trains to: (1) This installation also was the first time stop and hold main track, (2) take siding, that cab signals were used in lieu of (3) proceed on main track regardless of wayside signals for operating trains by superior trains.