RAILROAD SIGNALS of the U.S.
SIGNAL TIMELINE
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FEW SIGNIFICANT HISTORICAL SIGNAL EVENTS
1828? - The Liverpool and Manchester RR in England is given credit to have used the first form of "signaling", having used policeman to stand at intervals along the right-of-way to signal passing trains as to the occupancy of the track ahead, in addition to keeping people off the track (4)(P.17) 1834
- Again, it is generally believed that the Liverpool and Manchester
was the first to use fixed wayside railroad signals, consisting of a
post with an iron bar holding a flag, which could be rotated to show
if the track ahead was occupied or not - if the flag was parallel to
the track, it meant the track was clear… perpendicular, it was not.
(4) (P.17) 1841
- First semaphore used on the London and Croydon Railway in England
(1)(P. 169) 1860 - The "gate signal" was developed as a crossing signal to protect the intersection of two railroads. The gate could swing to block either of the tracks, and could include a lantern for night time operation. (1)(P.136) 1860's
- the Smashboard signal was developed expressly to prevent entry to
an open drawbridge (1)(P.136)
1865
- The Reading and Philadelphia used white/blue/red to signify
proceed/caution/danger
1870 - First interlocking plant - Trenton NJ on the United New Jersey Canal and Railroad Companies, built by Saxby and Famer of London…. American rights for Saxby & Farmer was secured by Toucey & Buchana Switch Co of Harrisburg PA (1)(P.169) 1870's - The Pennsylvania RR, well known for a long list of "firsts", was among the first to use semaphore signals for interlocking. (4)(P.39) 1871 - The Hall Signal Co was founded by Thomas Seavey Hall (this is according to a reference to Brignano and McCullough in "The Search for Safety", a publication put out by US&S). (4)(P.36) 1871 - Pennsylvania RR absorbed the Camden & Amboy, and block signal installation was completed between Jersey City and Philadelphia 1872
- basic track circuit invented by Dr. William Robinson, but not used
in any extent till after 1880
1873 - Daniels Rousseau's automatic signals installed on 3 miles of the NYNH&H, extended to 16 miles by 1876, but soon abandoned due to fatal flaws (2) ~1874 - The "crossing target" or "tilting target " signal was invented on the Pittsburgh, Fort Wayne and Chicago RR. (2) 1875 - The Boston & Albany RR had equipped 44 miles of track between Boston and Worcestor with Hall disc signals. (4)(P.39) 1875 - An organization met in Chicago, thereafter called the General Time Convention of Railway Managers, and recommended adopting a standard time for the railroads (1)(P.129 1878
- Dr. Robinson founded the Union Electric Signal Co
1882
- The Pennsylvania RR installs its first electro-pneumatic lower
quadrant semaphores. (4)(P.39)
1891
- Pattenall goes to work for the B&O RR, came from US&S (4)(P.60)
Late 1890's - Hall developed a "rotating semaphore" signal, where the blade was attached to a motor, and as long as the blade was moving, the engineer could proceed, if it was not, the engineer had to stop the train. At night, the signal was lit by a red light light, and if it was steady, the train had to stop, it is was flasing, the engineer could proceed. Tested successfully on the Delaware, Lackawana, and Western RR, but never used much. (1)(P.149) 1892
- The Board of Trade in England required the use of green instead of
white for "proceed". (3)
1893 - The CNW RR replaces white with green for proceed in their 1893 rulebook, pre-dating the NYNH&H change in 1895, to whom credit is usually given to as being the first. (3) 1895
- A wig-wag style signal was invented by D. H. Wilson in February.
(8)
1901 - From a questionaire sent out by the Railway Signal Association, it was found that the average distance from the distant signal to the home signal was 1444 feet, and to the interlocking tower was 1750 feet 1903 - The Patenall three aspect upper quadrant semaphore signal (invented by L. F. Loree and Patenall this year) was adopted as standard by the ARA, and was the majority of new installations till 1940. (2)(3) 1903
- First AC track circuit and vane relay - US&S
1904 - It was reported in a 1908 article in Railway Gazette magazine, that there were 4,697 "enclosed disc" type signals employed in automatic block signaling service, the majority of which were manufactured by Hall. (4)(P.39) 1906 - From a questionaire sent out by the Railway Signal Association, it was found that for 15 roads queried, approx one-third of the mileage in the U.S., the average distance from the distant signal to the home signal was 3745 feet, and to the interlocking tower was 4025 feet. 1906 - The first of the three aspect upper quadrant semaphores was installed on the Pennsylvania RR between W Philadelphia and Elwyn PA. (3) 1906-1908 - Research by corning into lenses and colors, and they came up with the current green-yellow-red, replacing white-green-red 1907 - Interstate Commerce Commision established a Block Signal and Train Control Board, went out of exisitence in 1912 and it's function handled by the Safety Division…. In 1917 the name of the organization was changed to the Bureau of Safety of the ICC 1908
- Upper quadrant signals became the recommended standard.
1913
- The Pennsylvania RR starts electrification (9) 1915 - The Pennsylvania RR introduces (expirements) with the first version of the PL (position light) signal and it is nick-named a "tombstone" signal because the top of the signal was round and the signal resembled an old tombstone…… also, later adopted on it's affiliates the N&W and LV (9) 1915
- The ARA adopted the idea of classifying routes by allowable speed,
hence, speed signaling was developed. (2)
1918
-
By the end of WWI, white
for proceed was out and prohibited by the I.C.C.
1918
- Hall enclosed disc
(banjo) signals were no longer shown in the New York Central RR
rulebooks, as well as three arm lower quadrant semaphores (being
replaced by two arm upper quadrant semaphores). (2) 1921 - CPL's first used in their modern form on the B&O and affiliates. The first B&O section to get them was between Deshler and Hamlet OH. (4)(P.62) 1921
- The Pennsylvania RR's PLs started taking the shape and
configuration were are accustomed to today (9) 1924
- First remote controlled gravity hump yard - US&S and
1927 - GRS came out with the first Centralized Traffic Control machine, again, invented by Sedgwick Wright. CTC combines interlocking with automatic block signaling. (4)(P.63) 1927
- The first CTC installation was on the New York Central Ohio
Division between Stanley and Berwick OH. (4)(P.63)
1930 - The Pennsylvania RR introduced pedestal signals (9) 1930
- Searchlight signals with compound lenses appeared
1953
- The CNW replaces a white marker with a red marker on distant
signals. (3)
1967 - The Pennsylvania RR places their first signal to the left of the track it governs, on the Williamsport-Buffalo line, also placd 2 PL signals on a bracket post at CP-Lake IN (10) 1968
- American Standard purchases US&S and makes it a separate division
(7)
1998
- "GRS" becomes part of Alstom when it acquired Sasib, and the GRS
name went away
2000 - The CSX takes down the semaphores along the Monon route in Indiana and auctions them off at a closed and secure location in Rushville IN on July 8th. 2002?
- The last operating ball signal in New Hampshire is taken down.
I know schools don't like to have their students use Wikepedia as a reference, but it's so convenient… with that said, here's where I found my info: (1) Trains and
Technology: The American Railroad in the Nineteenth Century by
Anthony J Bianculli Another good signal reference book: Railway Signaling by Everett Edgar King (1921): http://books.google.com/books?id=I4Q5AAAAMAAJ&pg=PA14&lpg=PA14&dq=position+light+signal&source=web&ots=4OYZr-Kisf&sig=TblDwCGux5zMvNbHi-3LVkiq9Hw#PPA11,M1 US&S history:
http://www.switch.com/i_history.html
Interesting series of short notes on
signals:
http://www.rsme.org/signals.htm#(Part%201)
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NEW 12/15/2007
Last Modified:
27-Jan-2010