Written by James S. Farrior, W4FOK CFO #431

Commercial telegraph operators used to have two types of CW circuits. One was a “high speed” circuit, up to 400-wpm, which used punched transmitting tape and printed inked receiving tape (called “slip”). The other was the familiar operator with his bug and “mill”, with its speed set as that which the operators could send and receive for long hours.

 

The receiving operator never had a chance to hear code being sent much over 45-wpm. Some news services could send at slightly higher seeds, but since such broadcasts were copied simultaneously by many operators, it was not worth while to send it at a speed above that at which all of the operators could produce clean copy. What I’m saying is that there was no practical reason, and usually no available means, for typical telegraph operators to learn to copy or read code at very high speeds.

The old “high-speed” circuits produced inked slip at a rate that would keep several transcribing operators busy. The slip, after inking, was run across a sort of “bridge” just above the keys of the mill (typewriter) keyboard, and the operator had a floor pedal that allowed him to adjust its speed. The speed limit of the moving slip was the operator’s typing speed.

 

A trained operator could read the slip faster than his sustained typing speed. For instance, I remember that while typing as fast as possible, I could scan ahead to see what was coming, so as not to get surprised by some unfamiliar word, name, or number. I would have them figured out by the time they came across the bridge and were typed. The operator did all of this without a high degree of conscious concentration, and meanwhile could think of other things while doing it.

When I first began copying slip, it was below my fastest typing speed, because I observed the dots and dashes that made up each character. However, after some experience, I began to recognize the characters by their appearance without being consciously aware of the underlying code. After some additional time, entire words and groups of words were read at a glance. It was much the same as reading print, except that the characters were written in a different way. My output was limited by my maximum sustained typing speed.

 

There is some similarity in copying slip and in copying the code: the eye reads the slip and the ear “reads” the audible code. Some people can learn to read slip at a very high speed, just as some people can learn to read printed text much more rapidly than others. One limit on the speed of reading slip is the fact that the length of the word on the slip is longer than a word in normal print. To minimize this problem, the speed of the slip as it was being inked was adjusted to make the characters as short as practical so as to make the words shorter and more readable. Just like we learn to read print, we could have learned the “appearance” of the characters, without being concerned about dots and dashes.

Also from Jim Farrior, some additional comments:

 

In early 1941, while working at WVR, the Army's 4th Corps Area Net Control Station in Ft. McPherson, Ga., I snapped a photo of Jack Ivy transcribing slip. Jack was perhaps our fastest manual and "high speed" operator. He could transcribe slip for hours at about 80-wpm and he seldom made an error.

The "high speed" circuit was between WVR and WAR, the national Net Control Station in Washington, D.C. Message handling within the Corps Area was done by conventional radiotelegraphy.

The "bridge" over the mill, across which the slip was drawn, can be seen in the photo. A motor driven reel, not seen because of insufficient light, was located at the left. The slip, which is visible in the photo, was pulled across the bridge at a speed that was controlled by a foot switch, and was wound on the reel as it was transcribed.

As the inked slip came from the recording head, it was not wound on a reel, but was allowed to "spill" onto the floor. A transcribing operator would go to the recording head, grab the free end of the recorded slip and quickly wind a "figure 8" ball of slip around his thumb and little finger of his left hand. He would tear off the ball at a point between messages and take the ball of slip to his transcribing position, where he would thread the inside end across the bridge at the top of his mill. The ball of slip, which held a number of messages, would be placed upon the floor.

Several transcribing positions, such as the one shown in the photo, were kept busy. Typically, to provide variety, the operators would rotate between punching transmitting tape on a Kleinsmidt perforator, operating the sending head, operating the recording head, transcribing slip, and operating a normal manual telegraphy position.

When the transcribing operator would reach the end of a message form, he would drop a blank form in the mill's platen so that when the message was pulled out, the blank form would be rolled into place automatically. Thus, with one quick motion, the operator would remove the completed message form from the mill, place it in the clamp holder that can be seen just over the typewriter, and roll the new form into place for beginning the next message. A similar thing was done at the manual operating positions, and an office worker would continuously collect the messages from all of the clamp holders, so that they could be delivered or given to another operator for forwarding.

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