The Cryptologic Technician Rating

Today’s Cryptologic Technician can trace his 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.

What is a “Rating”?

Cryptologic Technician rating insigniaA Navy rating is defined as an occupation that consists of specific skills and abilities. Each rating has its own specialty badge which is worn on the left sleeve by all qualified men and women in that field. In the Navy and Coast Guard, pay grades E-4 through E-9 fall within a rating and reflect a distinct level of achievement within the promotion pyramid. There are:

  • General ratings
  • Service ratings
  • Emergency ratings

During the summer of 1927, five Marines attended Katakana training in Shanghai. In September 1927, they were transferred to Peiping where, under the leadership of Chief Radioman (CRM) Dorman A. Chauncey, they 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. Two Marine operators, along with Chief Chauncey, deployed aboard USS TRENTON (CL-11)1, and two additional Marine operators were deployed aboard 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

The 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 D.C. 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 know 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 communications intelligence 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

In August of 1943 an analysis of the activities carried out by OP20G 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 into 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.

After 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) Technician2
Specialist Q (IN) Radio Intelligence
Specialist Q (RP) Registered Publications

The Birth of the Communications Technician Rating

There was no CT rating designator prior to 1948.

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.3 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 rate designator.4

Prior to 1948, when an individual was advanced to Chief Petty Officer, the "Chief–C" preceded the rate designator. Radioman Chief was CRM, Yeoman Chief was CY.


Further changes to the Communications Technician rating occurred as the Chief of Naval Personnel, the Bureau of Personnel (BUPERS), and the Naval Security Group evolved.

1956 – 1957 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.

Two additional career fields were added to the CT rating:5

  • Communications Technician (Technical)—CTT for Non-Morse operations
  • Communications Technician (Interpretive)—CTI to identify linguists
1 May 1970 Effective this date, 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 Chief of Naval Personnel issued BUPERS Notice 1220 announcing a change in the title from Communications Technician to Cryptologic Technician. The change brought the designation of the CT into consonance with the Warrant Officer (744X), Restricted Line (161X), and Limited Duty Officer (644X) communities which were all identified as “Cryptology.”
  • The Cryptologic Technician (Administrative) (CTA) branch was merged with the Yeoman rating (YN) and was disestablished.
  • Advances in technology made the CTO branch obsolete and it was removed from the list of ratings.
2004 The new Cryptologic Technician (Networks) (CTN) branch was implemented to monitor, identify, collect and analyze information; provide data for digital network products, and conduct computer network operations worldwide in support of Navy and Department of Defense national and theater level missions.

Not All CTCs Are Cryptologists

On various Museum Ships, there may be references to C-TCs. For example, C-TCs are included in the Casualty List of the USS ARIZONA (BB-63) Memorial. This designation refers to “Chief-Turret Captain (C-TC).” The Turret Captain (TC) 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.


1The classification “CL” is that of a Light Cruiser.

2Apparently 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.

3The Specialist Q (RP) was incorporated into the Teleman rating.

4Two additional branches established in the early days: Y (Clerk) and S (Special Devices Operator and Technician). “Y” was disestablished in 1948 and “S” was disestablished in the mid 1950s.

5Prior to 1960 the duties assigned to CTI and CTT branch personnel had been assigned to various other branches.