Today’s Cryptologic Technician can trace their roots back to those enterprising Radiomen who taught themselves the Japanese Katakana code in the early to mid-1920s and established the first intercept station at Shanghai, China.
During the summer of 1927, five Marines attended Katakana training in Shanghai China and in September 1927 were transferred to Peiping China where, under the leadership of CRM Dorman A. Chauncey, established the second radio intercept station.

The Birth of Cryptologic Direct Support

The Marine detachment in Peiping performed the first known temporary deployment of Communications Intelligence personnel when two Marine operators, along with Chief Chauncey, deployed aboard the USS TRENTON (CL 11), and two additional Marine operators deployed aboard the USS MEMPHIS (CL 13) for the entire month of September 1928. Presumably this mission was to copy traffic from Japanese fleet exercises.

Early Formal Organization & Training

11.04.00 History of CT Rating and Officer Designators 2The success of these early intercept operations led to the establishment of a permanent school on the roof of the Main Navy building on Constitution Avenue in Washington DC where especially qualified Radiomen were trained to intercept and analyze foreign radio communications. During the 12 year life of this school at least 176 (150 Navy and 26 Marine), enlisted radio operators received their training. The group became known as the On the Roof Gang (OTRG). Many of these graduates formed the nucleus of the communications intelligence operations in the Pacific at the beginning of World War II.

The early ratings involved in the communications intelligence arena were what we now identify as “general service” ratings. Prior to World War II the majority of these ratings were Radioman and Yeoman. The need for qualified communications intelligence personnel greatly expanded during World War II and by 1943 the following ratings were part of the complement of the activities under the cognizance of OP-20-G:

  • Yeoman
  • Radioman
  • Specialist I (Punched Card Accounting Machine Operator)
  • Specialist P (Photographic Specialist)
  • Photographers Mate
  • Machinist Mate
  • Electricians Mate
  • Telegrapher (for teletype)

Skills Re-Assessment

11.04.00 History of CT Rating and Officer Designators 3In August of 1943 an analysis of the activities carried out by OP-20-G was conducted and the first effort to establish a rating for Communications Intelligence Enlisted Personnel was initiated. The analysis identified several distinct kinds of work which were not provided for under the ratings assigned. These activities were grouped in the following categories:

  • Cryptanalytical – Demonstrate the ability to use Cryptanalytic techniques and procedures.
  • Operation of Special Machines – Demonstrate proficiency in the operation of one or more types of analytical machinery.
  • Technical Research – Demonstrate the ability to solve practical problems in the specialized field.
  • Radio Intelligence – Demonstrate ability to handle practical problems in specialized field of Radio Intelligence.

11.04.00 History of CT Rating and Officer Designators 4After review and establishment of knowledge requirements for the various sub-specialties, the Specialist Q rating was established in early 1944 with the following branches:

  • Specialist Q (TE) – Technician
  • Specialist Q (IN) – Radio Intelligence
  • Specialist Q (RP) – Registered Publications

Note: Apparently the Operation of Special Machines and Technical Research sub-specialties were consolidated into Technician and, although not a part of the Communications Intelligence operation, Registered Publications clerk was added.

The Birth of the Communications Technician Rating

In 1948 the majority of the wartime Specialist ratings were disestablished. At that time the Communications Technician Rating (CT) was established; the Specialist Q ratings CR, TE, and IN were incorporated into the CT rating.  Four CT career fields were identified as branches:

  • A – Administrative
  • O – Communications
  • M – Maintenance
  • R – Collection

Although the CT rating comprised four distinctly different branches, the service member’s branch was not a part of the rating designator.

02.27.07 CAPT Jack Hotwitz.ANote: CAPT Holtwick, after serving as commanding officer of USS Platte (AO 24) was assigned to Headquarters, Naval Security Group as head of the Personnel and Administrative Department.  In that position CAPT Holtwick is credited with establishing the Communications Technician (CT) rating in the Navy with it various branches for enlisted personnel. 


In the 1956/1957 time frame, the CT rating was further sanitized when all the “General Service” ratings still serving in the Communications Intelligence field (Radioman, Teleman etc.) were converted to CT.

In 1960 two additional career fields were added to the CT rating: the Technical Branch (T) for non-morse operations and the Interpretive Branch (I) to identify linguists. Prior to 1960 the duties assigned to the T and I branch personnel had been assigned to various other branches.

Effective 1 May 1970 the CT rating was further refined when the addition of the “branch” to the CT rating designator. The third letter rating designator was added to better identify and manage each branch.

26 March 1976 BuPers Notice 1220 announced the change in title for the Communications Technician rating to the below six Cryptologic Technician ratings.  The purpose of this action was to bring the designation of the Communications Technician (CT) into consonance with the Warrant Officer (744X), Restricted Line (161X) and the Limited Duty Officer (644X) Cryptologic communities.

  • CTA –Administrative Branch
  • CTI – Interpretive Branch
  • CTM – Maintenance Branch
  • CTO – Communication Branch
  • CTR – Collection Branch (MM)
  • CTT – Technical Branch (SpecSigs, Classic Wizard, OPELINT, TechELINT)

1991 – CTR assumed Special Signals and Morse code

11.04.00 History of CT Rating and Officer Designators 801 Oct 2003 – EW rating converted to CTT rating.

Note: The origins of EWs date back to World War I when the British used coastal radio direction finders to locate and determine the direction of the German fleet before the Battle of Jutland. Since, the importance of technicians rapidly grew through World War II, the Korean War, the Cold War, and the war in Vietnam. In the 1970s the Navy began teaching radarmen and electronic technicians electronic warfare. Sailors holding the Navy Enlisted Classification to operate and maintain electronic warfare equipment were the first Sailors to be converted to electronic warfare technicians.

06 Feb 2004 – CTN – Networks rating established.

01 May 2005 – Cryptologic Officer Designators 1610, 1615, 164X AND 744X changed to Information Warfare Officer Designators.  1610 changed to 1810

01 Mar 2006 – CTO converted to IT rating for E1-E5 and 01 Oct 2006 for E6 and above

01 Oct 2007 – CTA converted to YN rating

2008 – CTM was disestablished and re-established in the same year

20 Apr 2010 – Cyber Warrant Officer Designator 743X established

22 Jun 2010: (ref NAVADMIN 206/10):

IDC designators are revised as the follows:

  • 180X – Meteorology/Oceanography (remains the same)
  • 181X – Information Warfare (disestablishes 161X and 164X designators)
  • 182X – Information Professional (Disestablishes 160X Designator)
  • 183X – Intelligence (Disestablishes 163X designator)
  • 184X – Cyber Warfare Engineer (New)
  • 185X – Any IDC Qualified officer billet (new)

All administrative changes for redesignation occurred 1 October 2010.

20 Oct 2015 – Information Warfare Technician Warrant Officer Designator changed to 781X, Information Warfare Limited Duty Officer Designator changed to 681X and Cyber Warrant Officer Designator changed to 784X.

10 May 2016 – officers with designators 181X, 681X, and 781X are designated as Cryptologic Warfare Officer.

11.04.00 History of CT Rating and Officer Designators 929 Sep 2016 – Navy Rating Modernization (ref: NAVADMIN 218/16).

CTI – B510, B511, B512, B515, B516
CTM – B520
CTN – B525
CTR – B540
CTT – B550

20 Dec 2016 – Effective immediately Navy suspends Navy Rating Modernization and all ratings are restored (ref: NAVADMIN 283/16).

Not All CTCs Are Cryptologists

On various Museum Ships, there may be references to CTCs For example, CTCs are included in the Casualty List of the USS ARIZONA (BB 63) Memorial. This designation refers to “Turret Captain.” The Turret Captain (CT) rate was terminated when Battleships and Cruisers that had turrets were decommissioned and all the gunship Aircraft Carriers had their turrets removed. The Turret Captain’s duties were to maintain, instruct, and take charge of the gun turret assigned. They were assigned to Aircraft Carriers, Battleships and Cruisers. Each turret was assigned a Chief Turret Captain, First Class Turret Captain, or both.

Source: John “Gus” Gustafson, CTRCM (ret)