In 1874, R. C. Rapier read a paper on the fixed signals of railways before the Institution of Civil Engineers in London [Min. Proc. ICE v.38, pp 142-247 (1873-4)]. This comprehensive paper was ever after referenced as giving the best account of early signals, and of the state of the art. In America, it prompted the American Society of Civil Engineers to appoint a committee on railway signals consisting of J. Dutton Steele, Octave Chanute, and Charles Fisher, who sent out a questionnaire requesting information on the systems of signals in use on their roads. The answers to this request were analyzed, and the Chairman, J. Dutton Steele, reported the results to the society a little more than thirteen months after Rapier's paper was read. This paper did for American signals what Rapier's had done for British.
There was, however, not much to report. The Franklin Institute, and Ashbel Welch, had made some studies in 1866 and 1867. Welch's report, adopted by the Western and Southern Railway Association in 1872, recommended the fail-safe principle, the manual block on double track, drawbridge and switch signals operated by the mechanism itself, humane treatment of flagmen, and uniformity of signals and regulations. None of this existed, of course, and Welch's own primitive manual block system was the only one in the country. It has always been the custom of railway managers to ignore engineers, since they much prefer learning by painful experience.
Steele briefly notes the automatic signals of T. S. Hall, and the advertisements of Siemens Brothers of London for automatic signals. The United States was already being considered fertile ground for signal sales, since little was made domestically. He defines some signaling terms, "as the American nomenclature does not appear to be very clearly defined in its application to signals." This was a kind way to refer to total ignorance. Most of the terms he defined were those that later became naturalized, but a few are unusual enough to bear repeating here. A vane was a board with two faces painted different colors that was rotated a half-turn to give its two aspects. Balls are light balls and lamps of various colors hoisted to a mast head. Vanes and balls are distinctly American, and disappeared when signaling became rational. A target was a 'disc' rotating a quarter-turn, or else (!) stationary. The unfamiliar semaphore was also defined, not very clearly. He probably had never seen one.
Steele disappoints us when he says he will not burden us with a mass of detail, but select those items that best show the variety of practice. He proceeds company by company, beginning with the anthracite-hauling Phildelphia and Reading, probably a favorite since he was from Pottstown. Blocks, he says, are used at tunnels and single-track intervals, but not generally. A curves and other dangerous points, 'signal towers' 30 to 50 ft. high have been constructed, from which a signalman can keep a lookout and signal to trains by means of two vanes on the top of the tower having (!) three sides, painted red, white, and blue for danger, safety, and caution. The two vanes are separated by a black screen, so that each can only be seen from its proper direction. A night, a lamp illuminates the vanes. At tunnels, the towers are connected by a telegraph wire for blocking. The towers look like squat lighthouses, even to the railed walkway around the upper story where the vanes were displayed behind glass. This was almost surely the origin of the term 'signal tower' in American parlance, which is unknown in Britain.
Similar towers controlled crossings at grade, including that of the Reading and the Philadelphia and Trenton (Ashbel Welch's company). These had vanes at right angles on the same axis showing red for one road and white for the other. Whistle signals were: one - apply brakes, stop; two - release brakes, start; and three - back. These, of course, are identical to the later standard. Hand signals were also the ones we know, and the signal colors were red, white, and blue. Torpedoes were used as stop signals. There were a few semaphores as station signals (not, unfortunately, illustrated), but no switch indicators. The towers were an extraordinary feature, used nowhere else.
The Philadelphia, Wilmington and Baltimore had whistle posts of surprisingly modern appearance, as well as some disc signals that cannot be understood from Steele's drawings. The drawbridge signal, displaying red and white lights and boards, is interesting. The ball signals show a pulley to each side of the mast, illustrated with no balls, with one high ball on the left, with two high balls on the right, and a high ball on both left and right. The balls are all labeled as red. These may well have descended from the New Castle and Frenchtown, and were probably used at the junction near Wilmington. Against this conclusion is the fact that they do not appear in the road's 1854 rule book, nor on the time card. 'Standard fuses' (fusees) are said to be used as danger signals; they were not used in 1854.
The New York Central and Hudson River is stated to be worked mainly by hand signals. Whistle signals were different and conflicting on the Central and Hudson River portions. Semaphores are mentioned as used at the 'several entrances to New York.' This refers to the brand-new Toucey and Buchanan interlocking at Spuyten Duyvil. Red balls are signals to westward trains, white balls to eastward, 'in some cases.'
The Boston and Providence, Eastern, and Maine Central apparently used a confusion of ball signals: black balls with red lights, red balls with red lights, white balls with white lights, black balls with white belts and red lights were used with different meanings at different locations, even on the same railroad. The popularity of the ball signal in this region is well-known; the last was still in service in 1960 in New Hampshire. The B&P - B&A crossing near Boston was signaled by G. F. Folsome's box signal with blinds in the two directions, only one of which could be displayed at a time. The same whistle and color signals as already mentioned seem to be common, but with variations. 'Bean's Atmospheric Signal' is reported to guard a crossing near Boston, showing that patent signals were already appearing, but no further mention is made of them.
The Detroit and Milwaukee, and the Lake Shore and Michigan Southern, use three-position semaphores as station signals. The signal illustrated is a primitive single-arm slotted-post semaphore, obviously English, with the arm pointing to the left, and a rotating lamp on top, showing red and green. The green is said to mean 'all right,' but it really means 'caution,' as in British practice of the day. There are high switch targets, showing a red disc and a red light for an open switch, the edge of the disk and a green light for a closed switch. Red and green flags are used for stop and caution. The British influence is obvious in the use of the semaphore and the green color.
For the Pennsylvania Company (the Fort Wayne, lines West) 'double semaphores' are mentioned. These are certainly the crossing targets of the form later familiar, an arm pivoted at the center, with lamps hung from its ends. Other than the few examples mentioned, fixed signals are said to be very rare in the West, but hand, color, and whistle signals were widespread and nonuniform. The West, of course, means Ohio and such.
The Erie used ball signals at crossings. The one illustrated was a large tin ball painted red, with a red glass waist. A lamp was hung inside the ball for the night aspect. When the ball was hoisted, it meant Stop. When let down into a wooden chamber close to the ground, it meant Proceed. White balls were also used for proceed, a better practice. At the Erie's Bergen Tunnel (just west of the Hudson) targets were provided at each end, and there was a telegraph wire between the signalmen. The quoted rule for operating the tunnel allows one train to follow another after 15 minutes if the preceding train is not reported clear, but not two. This permissive practice is a reflection of the heavy traffic, or to the unreliability of the wire.
The Pennsylvania is scarcely mentioned, except that the early high switch indicator is shown, and termed a 'good English switch signal,' which it was not. Steele attributes this advance to British practice, and it was certainly much needed in the United States. The Pennsylvania was instrumental in introducing the high switch indicator. Remember, the Reading had none, high or low. The Baltimore and Ohio did not return the questionnaire, but probably had no fixed signals at all, relying completely on hand signals, as was the common practice. No fixed signals were reported from the South or the Far West, and none probably existed.
Steele now expatiates on the information contained in Rapier's paper, approving of the increase in uniformity of signals occasioned by the semaphore, and then going on to interlocking, which, as he states, had previously made no headway in the United States. He notices that the Pennsylvania and the New York Central have installed interlocking near New York, but is not well-informed. The first Scientific American article on the subject was only then on the newsstands, and the second was not to appear until December. He could have gone up and looked, of course.
Several good points appear in Steele's summing-up, including even that signals should normally stand at danger, and that block signals can actually increase the capacity of a double-track line, as well as repeating Welch's cogent earlier recommendations. His lack of direct experience shows in his recommendation for vane signals, long recognized as inferior by British engineers. He mentions that laws already exist requiring trains to stop at grade crossings and drawbridges, and that signals that block one road while simultaneously clearing the other are desirable. Such signals, like the crossing target, indeed did soon come into wider use. The danger of such a signal's being changed in the face of a train that was not noticed approaching was brought out in the discussion of the paper. In the area of crossing signals, the United States was on its own; grade crossing were avoided almost completely in Britain.
Tunnels, he states, must be worked by the block system, instancing the Hoosac Tunnel, five miles long, where he suggests a block post in the middle. I would not like to be the operator there. He refers to major tunnels, of course, not the short ones you can see through. The Southern Pacific was soon to install an automatic tunnel block in California, the first fixed signals in the Far West.
In the discussion, Steele relates how nonuniformity of signals contributed to the Norwalk drawbridge accident, the first bad railway accident in the United States. At that time, the New York and New Haven used two blasts of the whistle for apply brakes, and one for release brakes. Other roads did the opposite, which later became the standard. The engineman, observing the draw out of position, frantically whistled for brakes, but the brakemen heard only one sound, the two blasts having merged in the haste. This demonstrated just how important it was to have one blast for brakes. The lesson was not appreciated for a long time.
The paper shows, reading between the lines, that fixed signals were nearly totally absent from American railways except at a few crossings, junctions, and drawbridges in the Northeast where indigenous or imported solutions had been applied. These consisted mainly of crossing targets, ball signals, vanes, and their night-time equivalents. They were all individually and manually operated, as were all switches, even those in main lines. Operation relied on hand and lamp signals that were not standardized. Signal colors were red for danger, white for safety, and blue for caution, if a third color was thought necessary. Isolated signals were used at stations, like similar ones in England thirty years earlier. It should be realized that we are talking about 1875, not 1855, and the railway system had become more mature, heavier, and faster. The early days of American railways were definitely over by this time.
By 1875, the Pennsylvania had adopted and refined Welch's block system, and was extending it over its complete main line. No other company adopted it, except for short, isolated sections. There were only two interlockings in regular service, one at East Newark on the Pennsylvania, and one at Spuyten Duyvil, on the New York Central and Hudson River. The British practice of green for caution was just now becoming common, though blue hung on here and there (the Chicago and North Western used blue for caution for some time). The closed track circuit had just been invented, by Dr. Robinson in 1872, but was not to be applied to any extent until after 1880. A few, rather unsatisfactory, automatic signals by T. S. Hall, and Daniel Rousseau, were being tried.
The Centennial Summer of 1876 was to boast the first power interlocking, even though mechanical interlocking had barely started. The idea did not prove practical, but it led, through George Westinghouse's persistence, to practical power interlocking in the 1880's. British practice, mostly through the affiliation of Union Switch and Signal and Saxby and Farmer, and by a stream of talented immigrants, became American practice as well. The comprehensive display of Saxby and Farmer at the Exposition helped this development. The typical American lower-quadrant semaphore arm with a tapered blade and a single red roundel had not yet appeared, but the 1870's were years of decision in American signaling practice. The seeds of later developments were planted, and a thorough revolution took place.
Steele's report appeared in Trans. Am. Civ. Engr., IV 147-240 (1875).
T. C. Clarke, et al., The American Railway (Secaucus, NJ: Castle 1988, reprint). P&R signal tower cut, p. 214.
Composed by J. B. Calvert
Created 9 May 1999
Last revised 28 July 2004