My 2 cents worth regarding the TT-4.....
The TT-4 (A) was a 1949 design. It really wasn't designed to replace the
Model 15s in
use at the time (TT-5), but was more or less accepted by the Army as it
to be both "tactical" and "light weight", compared
to all the other clunkers available
at the time. This was predicated on the fact that the Army had
approached the Teletype
Corp to produce light weight equipment for use in the field by the Army.
said "no" to the proposal because their (then) current lines
of equipment were so
successful, both commercially and militarily, and their production lines
were at 100%
capacity (they had no more production capability and could not expand or
Note also that the Model 15/19 designs dated from the mid-1930s, and
Army wanted something a bit newer in the post WW II period. The Army
something that was a "military" model, or at least
military-specific, since this was
going to eventually become a DoD-wide equipment-design system in years
A year or two after the TT-4 came out, Kleinschmidt brought out the
of the TT-76 as a complimentary piece of equipment to go with the TT-4.
essentially replaced the Model 19s (TT-7s) iniatially in tactical
installs and later
in some fixed stations. The TT-4/TT-76 combinations worked pretty well
Army, although, for some years, it was common to (still) see
older Model 15 printers working with the newer TT-76s, or Model 14
with a TT-4, especially in later-era AN/GRC-26B RATT rigs.
(Prior to the introduction of the TT-76, there existed a Teletype Corp
(I don't recall its' designation or model number). This machine was
in field applications because it was light weight, small, and consisted
of a standard Teletype Corp Model 15 motor, standard Model 15 keyboard
a tape perforator.....and was used to simply cut tapes. There was no TD
(We still had a few of these in Germany in the early 60s -- excellent
Many of these older and newer machines were used in fixed CommCenters as
well, in all types of configurations and combinations.....
The Army however, was not entirely satisified with the TT-4/TT-76
fixed CommCenters. No one really knows why. A refined version was
We later knew it as the AN/FGC-25X, which was billed as a complete
(unlike the TT-4/TT-76 which were separate components and not a
"set", and which
could be combined with other, older models of equipment).
It was the later TT-98 (TT-100) that actually replaced the Mod 15, and
as most of
us know, the TT-98 and TT-76 were "standard" configurations in
assemblages in later years. Some fixed stations also used them, and
these combination machines were billed as AN /FGC-21s). (The real
which did exist, was an entirely different machine using the same
but also a mixer unit from a Model 19 for use with the PYTHON One-Time
Looking thru my "stuff" in regard to the early TT-4s, it is
likely the Army's bigger
need at the time was for a small, light weight printer for use in the
field in a time
before all of the factory-built comm shelters came into being.....
Recall that during WW II and thru most of the 1940s, teletypewriters
mostly at Corps level and higher in the field, largely due to their
and bulk. Most of the equipment then in use was commercial-grade Model
gear. Such equipment did not lend itself well to either fast-moving
nor to the dust and dirt, and rough handling normally associated with
field duty. One must understand that the Army, especially during
maneuvers and exercises, always preferred the nastiest, harshest, most
undesirable climates, weather, and the like for troop training. The
here is that THAT was how real wars were likely to be fought anyway, and
the troops and their equipment had to stand up to it.
The concept of the field teletype probably started with the Army during
The "field" teletype was usually set up in one of two
a. a teletype machine(s) set up and operating in the back of a 2 1/2 ton
usually without a shelter or van assemblage. Most of these truck-mounted
teletypes were simply set up in the bed of the truck -- under the canvas
of the truck itself with whatever electrical and signal lines running
from a ground
location to the equipment in the bed of the truck. Very primitive by the
we got to know later on when factory-built shelters came into being.
b. a teletype, usually a Model 15 (printer) might also be set up the
but in a tent. Sometimes, more than one Model 15 might be in use at the
time ("different circuits").
Both of these set-ups were likely the forerunner of what later became
AN/PGC-1. The AN/PGC-1 was essentially a TT-4 printer, a wooden crate
it was packed in, and operating accessories (paper, ribbon, etc). Once
in the field, the wood crate became the table on which the TT-4 was set
use. Not sure if the AN/PGC-1 included a Terminal Telegraph unit (TH-5)
would have served as an early, tube driven, "modem" of sorts.
Both the Army and the Marine Corps used the AN/PGC-1 in the field.
In these configurations, there were often no off-line tape prep
traffic processed might be 'received" from somewhere else, usually
Any traffic that had to be "originated" was usually typed
online directly by the
op. The concept of the self-contained CommCenter had not yet been
Neither had the separation between "tactical CommCenters" and
operations, as both were more or less considered one and the same.
During the Korean War, things began to change. Shop-built shelters came
to house and operate this equipment. Most of these were made of wood and
like huts placed on the back of a large truck. As time developed, the
refined for different types of uses by different types of units and by
the end of the
Korean War, several variations has been produced and were in regular use
So far as I know, the first mobile or tactical teletype shelters used by
were the highly successful AN/GRC-26A series and most of these were used
early HF RATT. These rigs were mounted on the bed of a 2 1/2 truck and
provided with a trailer-mounted 5 or 10KW generator for power which the
pulled. Models of trucks varied over the years from the old G735 Diamond
to the late-date M-35A1s and 2s thru thye 1960s when the GRC-26s were
phased out (culminating in the AN/GRC-26D which contained all
teletype gear). All of the GRC-26-series shelters were of wood
weather-proofed and held up well under heavy field use. A few later
some metal sides and roofing.
Along with the GRC-26s came other shelters, these being intended for
operations other than RATT. The most notable here was the AN/MSC-29
CommCenter van, which used the same prime-movers and generator sets as
26s, but which had considerably more teletype equipment installed (aboug
of Klineschmidt gear, 8 TT-4s and 8 TT-76s, plus the capability for
Terminal Telegraph equipment, a field telephone switchboard (SB-22), a
safe, a small desk, operating accessories, patch panels, power hocks,
purpose-installed outside binding posts for various line and circuit
The AN/MSC-29 was a unique piece of equipment in that is was designed
multi-purposes. At Division and Corps levels, it could be used as a
relay van, or it could be used as a terminal station. In any event, it
had a great
deal of capability and could support 4 full-duplex or 8 half duplex
TTY circuits. Having worked in these vans extensively over the years,
common equipment and "staples" of many signal units throughout
the US Army
for many years, including the Vietnam War years. As the need for
and message traffic increased over the years in field units, it was
see two (2) AN/MSC-29s set up back-to-back operating a large Signal
at Division level, or in the case of an Army Corps, with as many as 28
of them lined
up in 2 rows, also back to back, operating a field Major Relay station
(i.e. as with
VII Corps, 34th Sig Bn in Europe).
I do not believe any other services operated the AN/MSC-29s.
Aside from the 29 vans, the Army had, over the years, developed many
teletype vans. Not far behind was the Air Force which developed its' own
CommCenter vans (and the Air Force also used the AN/GRC-26Ds in the
and 60s, but theirs were usually mounted on an International Harvester
truck bed, in a day long before the ground-mobile "mobilizers"
I can find no record of the Marine Corps ever using the larger
Likely, these would not have been practical for an assault force on the
but they worked fine for a slower-moving occupational force, or for
semi-fixed (static) situtations in a field or fixed environment.
Hope this info is helpful,
Kleinschmidt manuals available at http://rattrig.com/manuals/tm%27s.htm
It looks like the contract date is "51", so it was probably made
in the mid 50's. In 1967 in RVN, the Army was using TT-4A, B & C
models. The TT-4 was the new Kleinschmidt Co.'s first product and was
accepted by the Signal Corps as their standard teletypewriter c1950 to
replace the Teletype Corp. M15.
Note the hooks on the side of the bottom plate that are not used to secure
the cover. They are to allow you to strap it to your pack frame for
"easy" transportation! (after all it is "portable":
TT-4 is major component of AN/PGC-1)
Looks like a "parts" machine, or leave the cover on!