Question regarding signal code books and signal corps

[Gary]

The semi-ironclad Keokuk was sunk in Charleston Harbor during Admiral DuPont's failed attack. Besides salvaging its guns, the Confederates also salvaged the signal code book. However, they were unable to understand it and used deception. Luckily, a Union signal officer was held prisoner in Charleston and a Confederate donned the blue coat of the yankees and misled the Union PoW into believing that he was a recently appointed signal officer and that he was going to be exchanged soon. He explained that he needed to learn the signals and thus was taught them by his fellow prisoner. Upon being exchanged, he promptly taught his fellow Confederates and thus the Confederates at Charleston were able to read the signals between the Federal Navy & Army. (See Col. Charles H. Olmstead's “Reminiscences of Service in Charleston Harbor.” SHSP, Vol. XI, April-May, 1883, Nos 4-5, 161.)

So, here's my question. If one has the signal code book, why the deception? Shouldn't one be able to understand it straight from the book or is there something more elaborate here? Thanks in advance.

[indguard]

Perhaps it was because they only had the coded messages but not the key to the code?

Oooor, the story is bunk?

[Gary]

Charles Olmstead mentions the incident in “Reminiscences of Service in Charleston Harbor.” SHSP, Vol. XI, April-May, 1883, Nos 4-5, 161. So does Major Robert Gilchrist in his booklet, The Confederate Defense of Morris Island.

[indguard]

Interesting. Cool story, regardless.

Still, I'd suggest that doesn't automatically make it true. Remember, there were decades after decades filled with books that told the BS stories of General Gordon when a BUNCH of them were simply made up to spice his book up!

Anyway, maybe my first thought was right? It seems to me that they just didn't have the key to the code, but had the code itself.

[Gary]

The book should have been the key, but it wasn't enough for the Confederates to have read the messags. After the deception, they were able to read the messages between Union General Gillmore commanding the ground forces and Admiral Dahlgren who commanded the blockading squadron. This was especially helpful when they learned of the amphibious assault against Fort Sumter and prepared a warm reception for the visiting Yankees.

[tompritchett]

Makes me wonder whether or not there was a layered code. First, a code for translating the signals into words which have no apparent meaning and then a second code that relates the words to specific military terms. Very similar to what the Navy did with the Navaho code breakers. Not only were the operators talking in Navaho but they were using code words rather than the actual words for the messages (e.g. the Navaho word for turtle for "tank").

[Sgt_Pepper]

They didn't use it as another layer of code, they used it because there was no alternative. As there is no word for tank in the Navaho language, nor any other modern term (and why should there be?), it was necessary to subsititute some other word for the object, thus the use of tortoise (chay-da-gahi) for tank et cetera.