PART B - TRI-SERVICE TACTICAL COMMUNICATIONS
Overview. TRITAC is a tactical command, control, and communications program. It is a
joint service effort to develop and field advanced tactical and multichannel switched
communications equipment. The program was conceived to achieve interoperability between
service tactical communications systems, establish interoperability with strategic
communications systems, take advantage of advances in technology, and eliminate duplication in
separate service acquisitions. Each component of the program is assigned to one of the services
to develop and acquire for the entire defense community. The major components assigned to the
Army are the AN/TTC-39 family of voice switches and the AN/TYC-39 message switch,
multichannel transmission equipment, and user voice and message processing terminals and
devices. To accommodate the need for a tactical communications system at EAC, HQ DA
directed that the heavy TRITAC components would operate at those command levels. This EAC
architecture is the essential link that facilitates and ensures timely, secure, two-way
communications between strategic command authorities and their tactical fighting forces.
TRITAC Equipment and Capabilities. The TRITAC system consists of switching
equipment, transmission equipment, and network control facilities.
a. TRITAC switching equipment. This equipment provides automatic switching
service, reconnecting analog and digital uses between tactical and Defense Communications
System (DCS) switches, and between U.S. and NATO national switches.
(1) Circuit Switch AN/TTC-39 is the heart of the multichannel switched network. It
provides a means of connecting telephones, message traffic, and data users in both the secure and
nonsecure modes in the EAC area network. It comes in several versions.
(a) The V2 and V4 versions can secure up to 600 customers. They are housed in
two S-280 shelters ( switching shelter and a control shelter). Either version requires two 5-ton
and two 212-ton trucks to transport its equipment. A 60-kw generator supplies needed power.
Figures 1-23 and 1-24, pages 1-32 and 1-33, illustrate the interior view of a V2 or V4 switch.
(b) The V3 version has a 300-line capacity. It is housed in a single S-280 shelter
(switching shelter) and requires one 5-ton and two 2 1/2-ton trucks to transport its equipment.
Power is supplied by a 30-kw generator. Figure 1-25, page 1-34, shows the interior of a V3
(c) The alpha version (AN/TTC-39A) has a 744-line capacity. It is housed in a
single S-280 shelter and requires one 5-ton and two 2 1/2-ton trucks to transport its equipment.
Power is provided by a 30-kw generator. Figure 1-26, page 1-35, illustrates the interior of a