Country of origin |
United States |
Entered service |
1987 |
Weapon caliber |
84 mm |
Projectile |
84 x 462 mm |
Weight |
6.7 kg |
Projectile weight |
? |
Warhead type |
HEAT |
Length |
1 020 mm |
Muzzle velocity |
290 m/s |
Sighting range |
500 m |
Range of effective fire (against tanks) |
300 m |
Range of effective fire (against area targets) |
500 m |
Armor penetration |
400 mm |
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The Alliant
Techsystems M136 is a license-built copy of
AT4
anti-tank weapon, with a few modifications to the original design
made at the behest of the US Army. It was procured as a replacement
for the
M72 LAW anti-tank rocket launcher, and was eventually procured
by the other branches of the US armed forces as well.
For all the press the
M136 receives that make it almost synonymous with the US Army today,
it was not a weapon they had intended to buy, as it had three
qualities that the Army's procurement system generally regarded as
deal-breakers; it was not originally an Army project, it was not
based on an Army idea, and it originated from a foreign nation. In
1980, the Army would have been especially insulted by the notion of
buying a variant of the AT4, as they were already grooming a
preferred weapon in the same class for service with the US military
--- the
FGR-17 Viper. However, the Viper program gradually fell to
pieces over time, as all of its objectives ultimately backfired; it
produced a weapon that was not only no more powerful than the M72
LAW (the main objective of the Viper program had been increased
armor penetration), but it was also much less reliable, much less
safe to operate, and cost more by 1982 (at $787 by May of 1982, the
Viper's unit cost was 10x as high as the $78 the Army's 1976 promise
for what it would cost by the mid-1980s). So furious was Congress,
that they not only totally defunded the Viper program, but also
ordered the Army to buy a weapon that was already developed. As no
such alternative was available from the US arms market, the Army was
forced to shop abroad.
While the Marines opted for a reloadable weapon to replace
the M72 LAW, the US Army insisted on a disposable weapon. They ended
up evaluating the British LAW 80, the West German
Armbrust, the
French APILAS, and the Swedish
AT4. The Norwegian M72A5 was also
evaluated in the competition, but mostly for a frame of reference.
The Armbrust had been the best performer right from the start, but
for anyone observing the Army's treatment of that weapon in previous
years, it was obvious the Armbrust would not be selected (the Army
director of combat support systems, General Lawrence F. Skibbie, had
previously made policy for the Army that any alternative to the
Viper was not to exceed 5.44 kg (12 lbs) in weight or 760 mm (30 in) in length ---
the Armbrust, that had been offered to the Army as a Viper just
prior to the announcement of the mandate, weighed 5.9 kg and was 79
cm long). The result of the competition had been a tie between
the AT4 and the Armbrust, despite the AT4 being louder than the
other weapons (the Armbrust was exponentially quieter, and almost
smokeless and flashless), having the largest backblast area (the
Armbrust had almost none, due to its use of a countermass), and
being bulkier (the Armbrust was the smallest, barring the M72A5). So
naturally, the AT4 was formally announced as the winner in late
1983. It was then formally designated as the M136.
While the Army was satisfied with the performance of the AT4,
they requested a number of ergonomical improvements. These
modifications included hard rubber shock absorbers on the muzzle and
venturi, a new sling arrangement, a new foregrip, and new sights.
The Swedish Army observed these alterations, and were impressed
enough to have some of them introduced into the production model AT4
as well; as such, there are now few differences between the AT4 and
M136. In compliance with the Barry Amendment (a law that obligates
the US military to procure only US-made resources), a license to
produce the AT4 was awarded to Alliant Techsystems, who to this day
are the sole producer of the M136, and the weapon finally became
operational with the US Army in 1987.
The appearance of the M136 is almost identical to the AT4. A
couple of obvious indicators are the clip-on sights (if provided),
and a gold-colored band around the barrel (some AT4s seem to have
these as well, but few M136s are without them). Also, some AT4s were
produced and sold without hard rubber shock absorbers, but every
M136 has them.
The composition, projectile, backblast area, and firing
procedures for the M136 are the same as those of the AT4. In fact,
except for other information noted below, all other data on the AT4
applies to the M136 as well (which is quite fortunate, as discerning
one from the other is difficult at best).
The main difference between the two weapons is the attachable
optics. While AT4s typically employ proprietary telescopic sights
made by SAAB-Bofors, the M136 is fitted with sights produced by
several different US companies. The standard telescopic sights for
the M136's MIL-STD-1913 rail mount are the Raytheon AN/PAS-13E
passive thermal sight, and the L3/Insight AN/PEQ-15 laser and night
vision sight. The PVS-4 night vision sight, the PAQ-4A infrared
sight, and the PEQ-2 laser aiming sight are also compatible.
Interestingly, these same sights are all used on the
M141 BDM as
well, despite that weapon being an 83 mm rocket launcher; this
suggests the M141's projectile flies on almost the same trajectory
as that of the AT4 and M136.
As with the AT4, the M136 has a warhead configured to greatly
increase lethality after penetration through enhanced "Beyond Armor
Effects". Though also like the AT4, no two sources seem to agree
exactly how much RHAe it penetrates --- figures run from as low as
356 mm, to as high as 450 mm.
The first combat use of the M136 was in Operation Just Cause
(the 1989 US Invasion of Panama), followed by the 1991 Persian Gulf
War. It displayed good performance against armored vehicles and
light structures in these conflicts, but it was found to be wanting
when fired at thick-walled and hardened structures. These drawbacks
soon became painfully evident in the 1992 Battle of Mogadishu, when
US Army troops stranded in that city were forced to fight a long and
grim urban battle against hordes of gunmen attacking primarily from
nearby buildings.
US military M136s saw much additional combat throughout the
1990s and 2000s, notably in Operation Restore Democracy (the 1998 US
Invasion of Haiti), the Afghan War, the Iraq War, and the Syrian
Civil War. These conflicts further confirmed that the M136 was
adequate for use against all armored vehicles the US armed forces
were likely to encounter, but it was still wanting in engagements
against personnel and structures, which after initial operations
were virtually the only opponents that US troops encountered.
These and other experiences eventually led to the development
of the Swedish AT4-CS, which has a countermass allowing for firing from an
enclosed area, and a variety of different warheads to include HEDP
munitions for use against structures. In 2010, the US Army announced
that all M136s acquired in future purchases will employ the
countermass of the AT4-CS.
As of 2016, Alliant Techsystems has produced over 300 000
M136s (a production run mirrored by SAAB-Bofors' AT4 in Sweden) for
both the US military and export. At present, a new M136 costs
$1 480.
For a list of equivalent
weapons, see the
AT4 page.
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Article by
BLACKTAIL
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