CSLC-V

COMSEC Logistics Support - Vietnam

The history of COMSEC Logistics Support in Vietnam was driven by the growth of US Army involvement in Vietnam. As the Army role increased, so did their need for COMSEC support. The purpose we served (our Mission) was all about secure communications. The ability to communicate without the enemy being able to understand what was being transmitted.

Everything about COMSEC support was classified. The equipment, codes, methods and procedures were all closely guarded. The people directly involved with the mission all held crypto clearances. Who we were, what we did and how we did it were not to be disclosed to anyone.

Those unfamiliar with these organizations will benefit from some definition of terms.

Terms	Definition
COMSEC	An acronym for "Communications Security"
COMSEC Logistics Support	Control, accounting, maintenance and distribution of all COMSEC equipment, codes and materials. (This was the Mission of the CLSC-V).
CLSC-V	COMSEC Logistics Support Center - Vietnam The organization tasked with the overall COMSEC Logistics Support Mission in Vietnam. Control of all COMSEC materials moving into or out of Vietnam was the responsibility of the Center.
CLSU	COMSEC Logistics Support Unit A detached unit of men and equipment tasked with the COMSEC Logistics Support Mission in the area of Vietnam where they were located. These units were primarily focused on Tactical COMSEC equipment and materials.
Tactical Communications	Battlefield communications between ground forces, air support, artillery, river boats and command organizations. COMSEC equipment allowed the creation of secure voice radio nets, critical for corrdinated combat operations.

Narrative of the History

SKYTROOPERS OF 1ST CAVALRY DIVISION PREPARE TO BOARD ASSAULT HELICOPTERS FOR PLEI ME COMBAT SIGNALMEN WITH TASK FORCE OREGON ON PATROL	In the early days of US involvement in Vietnam (Pre 1962), there were very few communications security steps taken by Allied forces in Vietnam. Most of them were fixed station applications at Communication Centers (Comm Center). Field combat level communication security was mostly nonexistent. Radio traffic between the few forces that existed were usually transmitted in the clear or using manual codes. Manual coding and decoding of radio messages was a slow and cumbersome process, thus it was not usually done. The belief at the time was the enemy was unsophisticated and laked the equipment and knowledge to monitor our communications. This was shown to be a mistake over time. (See Chapters 7 & 8 of "Division Level Communications" study on the Center for Military History website for their story of the Communications Security Threat and the Army response to that threat.) At the time, it was the Us Army Pacific Command - Command Issuing Office (USARPAC CIO in Hawaii) that was tasked with all COMSEC matters under USARPAC command. They setup a Field Army Issuing Office (FAIO-V) in the Cholon district of Saigon to serve the needs at the time. Thus COMSEC logistics support in Vietnam was born. (Max - we will want to change this paragraph once you get the early story updated.) No matter where the Command of the units supporting COMSEC Logistics fell, the Control of COMSEC materials and equipment always came back to the FAIO and USARPAC CIO in Hawaii. The USARPAC Command Issuing Office (CIO) ultimately reported back to the Army Communications Security Logistics Agency at Ft. Huachua, Az. That was the US Army world wide control authority for all COMSEC matters. At one point, the CLSU's were lead by a team of two officers. A 1st Lieutenant was the Commanding Officer, and a Warrant Office as the Crypto Custodian. The Crypto Custodians reported to the CLSC-V were the Commanding Officers reported to the command organization in existence at the time.
CALIBRATING EQUIPMENT AT 1ST SIGNAL BRIGADE CAN THO SITE	The first regular signal unit stationed in Vietnam at the time (1962), was the 39th Signal Battalion. At the time, the 39th Bn was tasked as “responsible for the cryptographic distribution service and maintenance support for all US Army and South Vietnamese units in Vietnam”. Their maintenance capability was limited to board swapping with higher level repair requiring returning the equipment for Depot repair in the US. In 1964 the buildup of US troops in Vietnam began and would continue until 1967. Suddenly, whole Divisions of the US Army were being redeployed to Vietnam. Prior to this, most US troops were concentrated from Saigon south to the Mekong delta region. The incoming organizations were being deployed all over the country. Along with the combat units came some General Support Groups (53rd and 80th General Support Groups) that had COMSEC components. Around the same time, Signal Support Detachments from the US Army Depots in the US were sent to supply higher level repair capabilities. (Sacramento Signal Depot, Lexington-Bluegrass Army Depot, Tobyhanna Army Depot and Ft. Gordon Army Depot) Through redeployment and reassignment, these COMSEC components were all brought together under the control of the CLSC-V. Detachments formed from these units were created and positioned to be close to the forces they supported. Thus forming the units that would eventually be called the CLSU's.
COMBAT PHOTOGRAPHER OF 221ST SIGNAL COMPANY GETS A HELPING HAND FROM VIETNAMESE CIVILIAN MAN-PACKED RADIO OPERATED BY COMBAT SIGNALMAN IN 1965	Somewhere before 1966 the FAIO-V was split out of the 39th Signal Bn and re designated the 706th Signal Detachment. The 1st Signal Brigade came in country in April 1966. Then the 160th Signal Group came in April 1967. The 706th was deactivated and replaced by the 57th Signal Company, which was assigned to the 160th Signal Group of the 1st Signal Brigade. At this point, the COMSEC Support system in Vietnam was up and running. There were considerable efforts being spent on improving and securing the facilities of the CLSU's, but the units themselves were generally stable. As our tours of duty were 1 year, most of the personnel activity was a replacement rotation of new troops replacing those whose tour was done. It was a matter of performing the mission and maintaining the personnel needed to do so. At some point (help here Max) the use of Identification Friend or Foe (IFF) gear began to be used on helicopters and fixed wing aircraft. This equipment, its codes and materials were rolled into the CLSC-V mission. The CLSU's would ultimately be tasked and staffed to supply the logistics support for this equipment as well. The Vietnam Studies section of CMH website has a section "COMMUNICATIONS ELECTRONICS 1962-1970" that outlines the 1st Signal Brigade's role in Vietnam. There is a small, vague reference to our organization in this study. We were a very small and unknown part of the 1st Signal Brigade, which was a small part of the overall Army involvement in Vietnam. However, we fulfilled a critical role in support of the US fighting man in Vietnam.

The following chart shows the number of US Army troops in Vietnam over time (Source:CMH Logistics Environment) and when key changes in our organization were made. As many major Army units redeployed to Vietnam, the demand for COMSEC support grew as well. Incoming Divisions that had COMSEC components saw those groups reassigned into the CLSC-V organization. Therefore, there is a long list of unit designations that became what we knew as COMSEC Logistic Support in Vietnam.

References

The following sources have been used as reference in building this history.

1. Letter from Max Cram, CW4, USA, Ret. Max served multiple tours in Vietnam, always with COMSEC Logistics Support. He was stationed in Hawaii before the buildup, he supported early operations from Hawaii and he was involved in the building of the support network as the needs grew. He authored this letter in response to our plea for history for our website. Although he titled it 2nd CLSU, he describes the formation of the entire COMSEC Logistics support system. Many thanks to Max for sharing the information with us and helping me get the story right. (Denny 1/23/2007) (Max - I list the existing letter here just to show you what I have in mind. We will either put your new letter here or delete the reference if you are not ready when we first publish.)

2. Center for Military History is the on line site for the US Army's Historical Section, the unit charged with research and documentation of Army operational history. ( If you want the WHOLE story, this is the site for you.) The Vietnam War and Vietnam Studies sections were of great help. (Chapters 7 & 8 of the "Division Level Communications" document of Vietnam Studies gives a very good narrative on the issue of Communications Security and the Security Response. This is why the CLSC-V organization was created.)