N&W telephone "block" lines

[NW Mailing List]

Dr. Scheer asks about the arrangement of "block lines." May I offer a few observations, since I have inquired about this topic for years and have personally observed many block lines it in use. 

First, in my time on the N&W (1964-1979,) what was called the "block line" was a "round robin" arrangement where ever station was cut in (just like the "Train Wire" a.k.a. the "Dispatcher's Wire.") The Dispatcher's Wire was for his use exclusively. Business which did not pertain to the movement of trains was conducted on the "Block Wire." Really, that was a misnomer because trains weren't being "blocked" on the block line, and I think the term "block line" was just a not-so-accurate hold-over from the old days. 

But I think that the set up had been different before the advent of Automatic Block Signals, when trains were manually blocked from block station to block station (whether by Telegraph or telephone.) 

Unfortunately I never met and conversed with any N&W men who had manually blocked trains on the main line before the advent of Automatic Block Signals, but I have had conversations with men who manually blocked trains by Telegraph on other busy railroads (principally the Reading and the PRR) in the 1915-1925 era, and information they furnished is probably a good index as to how it was done on the other big railroads as well. These men told me that in telegraph days there were ALWAYS dedicated Block Lines between a block station and the adjacent block stations on either side. For example, say that a portion of track is controlled by block stations A, B and C. B always had a dedicated "East Block Wire" to A, and a dedicated "West Block Wire" to C. No other parties had access to these dedicated circuits, only A and B, or B and C. 

When I came "up north" to work in 1979, most of the towers were still in operation between New York and Washington, and between Philadelphia and Pittsburgh, and I found without exception all these towers had a dedicated telephone "Block Line East" to the next tower, and a dedicated "Block Line West" to the next tower. Of course, a lot of this was high-speed, 4-track territory handling a hundred or more trains a day, and seconds counted and the communications had to be instantaneous. 

Western Electric made a dandy "telephone concentration unit" for this purpose, and it accommodated ten telephone circuits. You have seen one in my Telegraph Office, but I'll attach a photograph. It was a box with miniature levers on the front (called "keys" in telephone work.). Pushing a key upward enabled the towerman to connect his headset to any of the lines which came into his tower/block station. In addition to a key, each line coming into the tower had a small light which lit when another station had rung the tower on one of the incoming lines. At the far right was an eleventh key, the ringing key, which rang the bell or buzzer and lit the lamp in the station being called. "Concentration Unit" was technical parlance, and most men referred to the device as a "Lamp and Key Box." 

Why might ten lines be coming into a single tower? Well, line one is always for the DS (Train Dispatcher) and in the case of a junction, or a location where Train Dispatching territories split, a tower may work with as many as three Train Dispatchers. Dispatcher's circuits usually had red indicator lamps on the concentration unit, whereas other lines had white. In electrified territory, one line always went to the Power Director. Two lines would be the Block Line East and the Block Line West. If a branch line were involved, there might be a Block Line to the next tower or block station down the branch. And one line was always the "Wayside Phone" line on which a conductor, signal maintainer or section foreman could ring the tower from a phone box. (If you will permit me one additional observation, east of Harrisburg on the PRR this was called the "Wayside Phone," but west of Harrisburg it was called the "S&S Wire." "S&S" stood for "Signal and Siding," because each signal and each switch to a siding had a telephone connected to the towers. I was one place which had one of the keys on its Lamp & Key Box marked "Bridge Line." I inquired as to what that meant and was told "Every signal bridge has a telephone on it, and all those phones are connected to that line. In other places, they call it the S&S Wire.") If the tower were near a major yard, there would probably be a "short line" telephone circuit to the yardmaster represented on the Lamp & Key Box. And if movements to/from another railroad were made at that location, there would likely be a telephone line to some office on that railroad (tower or Train Dispatcher.) So you can see that ten lines coming into a tower was not unrealistic. I have been in towers where more than ten lines came in, and there were TWO Lamp & Key Boxes. 

Another genuinely fascinating topic is "rings" on magneto phone lines. Generally there was a card posted in telephone boxes showing what the rings were for that location, e.g. "Ring three shorts for tower to the east; Ring two longs for tower to the west." In one place I worked, if the tower wanted to raise any conductor or section man standing near a telephone box, the ring was five shorts. Of course, no one ever needed to ring the Train Dispatcher, as he was constantly connected to the Train Wire. To raise the DS, you only needed to push the transmit button and say "Roanoke, Glade" or "Crewe, Lowry" and he would answer you when he had time. But remember that in the quintessential days of railroading, only the operators/towermen talked to the dispatcher... Conductors and all others talked to the operator/towerman. 

The above information is not N&W-specific, but I think it might help you get the gist of how communications were handled in the days when we still had stations and towers along the railroad. 

<< Photo Attached >> 

-- abram burnett 


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