A Visit to an Interlocking Tower

An Interlocking Plant and

The Man in the Tower

Accelerate Train Movement

by Tag A. Long

HAVE you watched a train worm its way through a network of yard tracks, apparently “pick” out the right one, and finally go out on the main line, seemingly with no one around to “throw” the switches? For, of course, the train really doesn’t pick out the right path to follow. A “tower man” (or perhaps a “tower lady”) does that. He, or she, is the interlocking plant operator--the “pilot,” who keeps the trains on the right tracks and guides them until they have a clear board ahead.

Ever since I made that trip with the circus, ’way back in the summer of 1927, I’ve had more respect for the “razorbacks” --the men who load and unload the flat cars. And from that time on, I believe I began to appreciate more fully the work which is being done on our railroad by the men behind the scenes. To these men, who rarely come in contact with the traveling public, belongs a full share of credit for the part they contribute in the safe and proper operation of trains.

An interlocking plant, according to the Book of Rules, is an assemblage of switch, lock and signal appliances, interlocked. That is a comprehensive statement which covers a multitude of things. The purpose of the interlocking plant is to place under a unified control the handling of a large number of switches and signals which permit the movement of trains from two or more tracks. The interlocking minimizes the possibilities of accident and speeds up train movement over the district controlled by it. The term, “interlocking,” applied to such a device as this means that the action of each switch, signal and lock is dependent upon the action of the other switches, signals and locks in the plant. A switch cannot be moved without affecting other parts of the mechanism.

I know you’ve met men like E. L. Whitehead, first trick operator at Bluestone. One of those kindly, jolly fellows with whom you want to make friends right off the reel. He’s one of them. Smokes a pipe and looks you squarely in the eye, with a merry twitch around the corners of his mouth most of the time. He’s a medium-sized man and his hair is slightly tinged with gray. When he talks, you get the impression that he knows what he’s talking about. He’s not over-talkative.

No, I couldn’t help liking him, as soon as Signal Supervisor C. G. Harris, who accompanied me to his “hang-out,” had introduced us. He was standing in front of an array of levers that looked like the mechanism of a battleship when I walked in. Mr. Harris told me he was then lining up the track through the interlocking plant so a train could pass through.

After Mr. Whitehead had finished I managed to get him to say something.

“These levers and ‘gadgets’ you see here, Mr. Long,” he began, “are hooked up with four switches, five Cross-over tracks and a total of 19 signals. These devices are necessary to govern train movements to and from the east- and westbound main tracks, to and from the Pocahontas Branch and siding, which jut out from the eastbound main track here at the tower; the Bluestone Branch, which branches off of the eastbound main tracks a short distance west of the tower, and the old eastbound main track and, making a loop, rejoins the new eastbound main at Ruth.

“Now the two switches and three crossovers, which are located too far west of the tower to be seen distinctly, are operated and locked by an electric current from a lever here in this tower. The other two crossovers and the two remaining switches near the tower are operated and locked mechanically by these long levers, which must be moved by the ‘armstrong’ method. In other words, when I pull this lever to a certain position it moves the switch. And when I pull this other lever it locks the switch. You understand that much, don’t you?

“Yes sir, that sinks in,” I said.

“But--I cannot move this lever if a train is approaching the switch after I have given it the signal to proceed, because the switch is locked. The presence of the train on the rails near that switch and in the block makes it impossible to unlock it in the usual manner. The reason for this is the fact that the train shunts out the current necessary to unlock this lever here in the tower. If, for any reason, the train becomes disabled and cannot move any farther and it is necessary to move the switch, the electro-mechanical device, which you see here just above the levers, can be operated and it will unlock the switch lever. This device works on a clock-work principle and from one-half to one minute is required for this device to complete its action. That acts as a safeguard. For if I should start to wondering whether the Athletics will beat Washington today with my hand on that time release, I’ll have time to make up my mind before any serious damage can be done.

“As you know,” he continued, “our train movement depends very largely upon our automatic block signals and interlockings. This plant is fully protected by these signals. Their normal position is at ‘stop.’ Suppose, for instance, that a train is approaching the tower on the westbound main track and is supposed to take the Pocahontas Branch for Pocahontas. If everything is clear on the eastbound main track (which this train must cross), I move a total of six levers, three to move the switches and crossovers and three to lock them up. After I have done so, I move one of the signal arms to ‘clear’ position and another to ‘proceed with caution,’ and the route is lined up for the train to go to the Pocahontas Branch. After I have made this arrangment it is impossible for me to throw any other switches or give any other signals which would conflict with the movement of this train to the Pocahontas Branch.”

I happened to look out of the window just at that moment and noticed the side track which led off of the Pocahontas Branch at the tower. An impish thought struck me.

“But suppose you would forget to throw the lever which controls the side track switch? Then the train would run into the siding, wouldn’t it?” I asked.

“Well, in the first place I am not supposed to forget, Mr. Long,” he replied with a twinkle in those gray eyes of his, “and in the second place if I did forget, the signal which the engineer receives would indicate to him that he must proceed at slow speed prepared to stop for any obstruction on on the track. This signal is always given automatically, when the switches are lined up for the siding.”

Everybody makes mistakes, but 23 years of experience in an interlocking plant will make anyone very perfect. Mr, Whitehead went to work as a telegraph operator on the Pocahontas Division at the age of 16. After several changes in location he came to Bluestone Junction as telegraph operator and tower man in 1907, where he has remained until the present time. He thoroughly understands his job and, believe me, he gets the trains through his plant promptly. Occasionally emergencies arise with which he must deal quickly and intelligently, but a cool head and a clear-thinking brain enable him to master the most difficult situations.

When he’s not working, you can find him over at Pocahontas, where he makes his home, When the weather is not too cold he’s out of doors caring for his flower garden and lawn, recognized as the most attractive in Pocahontas. Yes,he’s a Veteran. He attended the first annual meeting at Ocean View and says he had a “swell” time.

To understand how the tower man measures up to his duties, I’ll try to give you a little glimpse of the situation at Bluestone. When business is normal, just about 150 trains pass through the plant every 24 hours. This doesn’t sound so improbable when it is remembered that the tower controls the movement of trains over the eastbound and westbound main tracks, two branch line tracks and the old eastbound main line track. There are 14 regularly scheduled freight and passenger trains which pass through the plant every 24 hours. In addition, 22 branch line trains go in and out of the plant every day. These branch line trains run from Bluestone to Pocahontas and back again, thence to Boissevain, the terminus of the Pocahontas Branch, back to Bluestone, and from Bluestone to Simmons,Matoaka, Wenonah, with side trips up the Goodwill and Crane Creek Branches.

The misleading feature of these branch line trains is the fact that they are composed of only two units of equipment. Every time they reach a certain point, they change numbers and start out again as an entirely different train.

The passenger and through freight train movement makes up just about half of the traffic running via Bluestone Junction. The other half is composed of extra coal trains from the West going to Bluefield and coal movement from the Bluestone and Pocahontas Branches, This coal train movement is rather intricate, too. Coal is assembled from mines along the Bluestone Branch at Clift Yard and at Simmons. Electric locomotives bring the loads from Clift Yard through Bluestone Junction to Flat Top Yard, which is located about three miles east of Bluestone. Here the eastbound coal loads are assembled into long trains and moved on to Bluefield. The westbound coal is picked up at Flat Top Yard by westbound trains. Coal from the Pocahontas Branch is also moved electrically to Flat Top Yard through Bluestone Junction. However, in order to facilitate the movement of this coal from the two branches, a number of trips are made by the electric locomotives back and forth through Bluestone. All of which increases the number of trains for which the tower man at Bluestone must be on the lookout and must handle through this interlocking district.

In addition to being an interlocking tower operator, Mr. Whitehead performs the regular duties of a telegrapher. He “O. S.’s” trains to the dispatcher, delivers necessary train orders to the crews, and keeps a record of each and every train as it passes his office. As everybody knows, the operator is the dispatcher’s “nerve” through which he keeps in contact with train movement over the line. In performing this function, Mr. Whitehead is no exception to the general rule. He sends mes- sages and his office is a general information bureau for train crews, signal maintainers, section foremen, etc.

I was watching Mr. Whitehead take a train order from the dispatcher when the ringing of a bell attracted my attention.

“What does that mean, Mr. Whitehead?” I asked.

“That means a train is coming,” he replied.

Pointing to a large glass-covered track diagram above his levers, he said: “See that little light there? Well, that indicates the exact position of the train that caused the bell to ring. The light burns because the train has established contact between the two rails in a certain block. These rails carry an electric current. The bell was rung from the same source. The purpose of the bell is to call my attention to the approach of a train, so that I may have time enough to line up the tracks properly and to give the proper signals. It mav interest you to know that the absence of the same electrical circuit which rang the bell and flashed the little light is responsible for the movement of the signal arm from clear to stop position when a train is in the block protected by this signal. I say ‘absence of’ because the presence of the train on the rails shunts out the current from what is called a ‘relay.’ This relay prevents the current from flowing to the signal mechanism and allows the signal arm to fall. This is why it is impossible for me to change the signal indication after a train is in the block. Simply because all of the physical strength in my body cannot force current to flow into the signal mechanism.

“Yes, this interlocking tower is just about as ‘fool-proof’ as it is possible to make it,” Mr. Whitehead continued. “As long as one follows instructions and the dictates of common sense, the chances of accident are pretty slim. It is only when the interlocking mechanism is superseded by a voluntary action on the part of the tower man or the train crew that any serious error can be made.”

Often when one ponders over the intricacies of a machine, the mind forms questions, which, on the surface, seem perfectly logical, but which, with a little further thought, fall to pieces and seem idiotic. Such a question was one of several which I popped to Mr. Whitehead. This was it:

“Why do you have to pull so many levers when you want to line up the track? Why wouldn’t one do the work?”

He was patient, however.

“In the majority of cases,” he replied, “when I move one switch it is necessary to move another one, because the position of other switches between the track from which the train is emerging and its destination would lead it off of the desired route.”

After he had finished explaining he sat silent for a moment. It seemed as if his attention was being entirely devoted to rings of blue smoke emanating the bowl of his pipe. But the expression in those gray eyes told me he had something else to say if given the opportunity.

“Everybody seems to have something to say to you as they go by, Mr. Whitehead,” I led off. “I suppose you have quite a few friends in this neck of haven’t you?”

“Yeah, I was just fixing to tell you that friends mean a lot to a fellow on a job like mine. Come to think of it, though, I guess I ought to have a few friends around here. I’ve been here long enough. It’s worth a lot to work with fellows who know you and with folks you know and like.”

I agreed with him thoroughly.

N&W Magazine, August 1930, pp. 514-516