Codes Used in Early Wireless Telegraphy
By Paul Bock,
K4MSG of Hamilton, Virginia
Click here for other articles by Paul posted to the LARG Internet Site
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Preface By Paul Bock - K4MSG - December 16, 2008
This article may be of interest to the LARG members. I sent this one to John Maxtone-Graham, renowned author of books on maritime history, whom I met and heard lecture while on the cruise from which I just returned. He's a very nice man, very knowledgeable on maritime history and a real "Titanic" history buff.
We left the U.S. on Nov. 18 and spent 3 days in Rome, then went on board the Grand Princess and spent the next 3 weeks cruising the Mediterranean, down the west coast of Africa, across the Atlantic to South America, then up through the Caribbean to Fort Lauderdale, arriving last Saturday morning. We flew home from there Saturday afternoon.
Didn't do any hamming but it was interesting to visit some of the places I've worked over the airwaves like Italy, the Vatican, Spain, Gibraltar, Morocco, Senegal, Brazil, French Guiana (Devil's Island), and Dominica. Very nice trip, I could get used to that laid-back lifestyle real fast. :-) Best Regards, Paul - K4MSG - December 16, 2008
Follow-On Comments By Paul Bock - K4MSG - January 17, 2009
The article that was published on early wireless codes
had several errors including misidentification of a ship (it was USS Chester, a Navy cruiser, and not SS Chester, a commercial ship) and some minor errors in how the codes were used and their relationships
to one another.
This is a corrected version which is more accurate. There is also some interesting information at
the bottom of the article on the code requirements for Navy radio operators in WWI. Those guys had to be GOOD! Best Regards, Paul - K4MSG - January 17, 2009
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In a New York Times interview dated 19 April 1912 the surviving wireless operator of RMS Titanic, Harold Bride, made some interesting comments regarding his difficulties in achieving efficient wireless communications after his rescue and delivery to RMS Carpathia. In the interview Bride singled out the wireless operator on the American Navy cruiser USS Chester for the latter's ineptitude, particularly his inability to copy "Continental Morse" rapidly and efficiently. In order to clarify the problem of differences in telegraphic codes at the time of the Titanic disaster the following historical background and explanation may be of help.
When Samuel F.B. Morse invented his land-based telegraph around 1840 he also developed a "code" made up of dots and dashes to represent letters, numerals and punctuation. This code, which came to be called "American Morse Code" or simply "Morse Code," was used on American railroads and by the land-line telegraph messaging service (e.g., Western Union) until it was eventually phased out completely in the 1960s. It is also sometimes euphemistically referred to as the "railroad code."
In Europe in 1848 a similar code was developed in Germany and thereafter variously referred to as the "Continental Code," "Continental Morse," "International Morse," etc. It is of similar construction to American Morse code - 15 of the 26 letters of the alphabet are identical in the two codes - but there are also significant differences. Eleven of the letters, nine of the numerals, and all of the punctuation marks use different dot-and-dash combinations in the two codes, and to make matters worse American Morse deviates in some instances from maintaining a standard time relationship between the length and spacing of the various elements of the code (dot, dash or space). The Continental Code, on the other hand, uses a very strict timing relationship in this regard for all letters, numbers and punctuation. The aggregate effect of these differences is to make it somewhat more difficult for an operator to become proficient in both codes.
As maritime use of wireless began to grow in the period between 1900 and 1912 the Continental Code became the default standard for transatlantic ocean-going vessels (and was coincidentally the standard code for all Morse-code types of communications throughout Europe) but in America the coastal ships continued to use the American Morse code. This created the possibility of confusion that could have hindered communications between ocean-going vessels and coastal vessels during an emergency.
To make matters worse, in the early 1900s the U.S. Navy developed its own code for use by Navy wireless operators. This code shared only four letters with Continental Morse and three with American Morse. The not-too-surprising result was that Navy operators, while proficient in their own code, could hardly be expected to know both American Morse and Continental Morse as well and in fact this shortcoming was evident at the time of the Titanic disaster. The Navy operator on the USS Chester - and perhaps other Navy operators on other unnamed U.S. ships - was singularly inept in Continental Morse as reported by Harold Bride in his interview.
All of this confusion regarding codes came to an end after the Titanic disaster when the international community adopted the Continental Code as the universal code to be used for maritime wireless (later radio) telegraphy. This eventually extended to all wireless communications with the name ultimately changed to "International Morse Code." It was sometimes called the "Radiotelegraph Code" in the amateur radio community and even occasionally still referred to as the Continental Code as late as the 1950s (the Boy Scouts of America sold a code-training key-with-buzzer kit that had the "Continental Code" embossed on the bakelite body of the device). American Morse was confined to land wire-line use only and that primarily in the United States, and the Navy Code disappeared completely.
NOTE: Navy radio operators were still required to know American Morse Code even after the adaptation of the Continental Code for wireless use, primarily because U.S. coastal ships continued to use American Morse for some years after 1912. The code tests for Navy Radiomen during WWI were 25 wpm Continental and 15 wpm American Morse for Petty Officer 2nd Class, 27 wpm Continental and 20 wpm American Morse for Petty Officer 1st Class, and 28 WPM in both codes for Chief Petty Officer.
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