The BGM-71 TOW (“Tube-launched, Optically tracked, Wire-guided”) is an American anti-tank missile. TOW replaced much smaller missiles like the SS.10 and ENTAC, offering roughly twice the effective range, a more powerful warhead, and a greatly improved semi-automatic guidance system that could also be equipped with infrared cameras for night time use.
First produced in 1970, TOW is one of the most widely used anti-tank guided missiles. It can be found in a wide variety of manually carried and vehicle-mounted forms, as well as widespread use on helicopters. Originally designed by Hughes Aircraft in the 1960s, the weapon is currently produced by Raytheon.
Design and development
Initially developed by Hughes Aircraft between 1963 and 1968, the XBGM-71A was designed for both ground and heliborne applications. In 1997, Raytheon Co. purchased Hughes Electronics from General Motors Corporation, so development and production of TOW systems now comes under the Raytheon brand. The weapon is used in anti-armor, anti-bunker, anti-fortification and anti-amphibious landing roles. TOW is in service with over 45 militaries and is integrated on over 15,000 ground, vehicle and helicopter platforms worldwide.
In its basic infantry form, the system breaks down into a number of modules: a folding tripod mount, a launch tube (into the rear of which encased missiles are inserted), a mandatory daysight tracker unit, which can be augmented with an optional AN/TAS-4 or AN/TAS-4/A gas-cooled night sight (or an all-in-one tracker unit on the M41 ITAS version), and a traversing unit, which mounts onto the tripod and carries the launch tube and sight, that also includes the weapon’s trigger and the bridging clamp, which mates with the missile’s umbilical data connector. In addition to this main assembly, there is a separate fire control system (FCS) module, which performs all guidance calculations, and a battery pack to power the system. These two modules link to each other, with the FCS then linked to the daysight with a cable.
When the target is sighted and the trigger is pulled, there is a 1.5-second firing delay while the missile spins up its internal gyroscope and the thermal battery reaches operating temperature. Once this concludes, the launch motor fires through the rear nozzle propelling the missile from the tube: this soft-launch motor fires for only 0.05 seconds and burns out before the missile has exited the tube. As the missile exits the launch tube, first four wings just forward of the flight motor spring open forwards, followed by four tail control surfaces, which flip open rearwards as the missile completely exits the launch tube. As the wings fully extend at about 7 meters from the launcher, the flight motor ignites, boosting the missile’s speed to approximately 600 miles per hour (~1,000 kilometers per hour) during its burn time. At 0.18 seconds after launch, around 65 meters from the launcher, the warhead is armed by G-forces from acceleration by the flight motor, a safety feature intended to protect the operator if the flight motor fails to ignite. The flight motor burns out 1.6 seconds after launch, with the missile gliding for the remainder of its flight time. After the tracker captures the missile, IR sensors bore-sighted to the daysight tracker continuously monitor the position of an IR beacon on the missile’s tail relative to the line-of-sight, with the FCS generating course corrections which are sent via the command link to the missile’s integral flight control unit. The missile then corrects its flight path via the control surface actuators. The operator keeps the sight’s crosshair centered over the target until impact: if the missile fails to strike a target, the command wires are automatically cut at 3,000 meters on the original TOW and 3,750 meters on most current-production TOWs. An automatic wirecut also occurs if the tracker fails to detect the missile’s thermal beacon within 1.85 seconds of launching.
The TOW missile was continually upgraded, with an improved TOW missile (ITOW) appearing in 1978 that had a new warhead triggered by a long probe, which was extended after launch, that gave a stand-off distance of 15 in (380 mm) for improved armor penetration. The 1983 TOW 2 featured a larger 5.9 kg (13 lb) warhead with a 21.25 in (540 mm) extensible probe, improved guidance and a motor that provided around 30% more thrust. This was followed by the TOW 2A/B, which appeared in 1987.
Hughes developed a TOW missile with a wireless data link in 1989, referred to as TOW-2N, but this weapon was not adopted for use by the U.S. military. Raytheon continued to develop improvements to the TOW line, but its FOTT (Follow-On To TOW) program was cancelled in 1998, and its TOW-FF (TOW-Fire and Forget) program was cut short on 30 November 2001 because of funding limitations. In 2001 and 2002, Raytheon and the U.S. Army worked together on an extended range TOW-2B variant, initially referred to as TOW-2B (ER), but now called TOW-2B Aero, which has a special nose cap that increases range to 4.5 km. TOW-2B has top attack capability. Although this missile has been in production since 2004, no U.S. Army designation has yet been assigned. Wireless versions of the TOW-2A, TOW-2B and TOW-2B Aero have been developed that use a “stealthy” one-way radio link, identified with the suffix “RF”. These missiles require no special alterations to the launcher, since the RF transmitter is encased along with the missile and uses the standard umbilical data connector.
In 1999, TOW received the Improved Target Acquisition System (ITAS).
The TOW missile in its current variations is not a fire-and-forget weapon, and like most second-generation wire-guided missiles has Semi-Automatic Command Line of Sight guidance. This means that the guidance system is directly linked to the platform, and requires that the target be kept in the shooter’s line of sight until the missile impacts. A fire-and-forget TOW variant (TOW-FF) was under development, but was cancelled by the Army in 2002.
In October 2012, Raytheon received a contract to produce 6,676 TOW (wireless-guided) missiles for the U.S. military. Missiles that will be produced include the BGM-71E TOW 2A, the BGM-71F TOW 2B, the TOW 2B Aero, and the BGM-71H TOW Bunker Buster. By 2013, the U.S. Marine Corps had retired the air-launched TOW missile.
- XBGM-71A / BGM-71A TOW missile produced by Hughes
- BGM-71B BGM-71A variant; increased range
- BGM-71C BGM-71B variant; System implementation (ITOW)
- BGM-71D BGM-71C variant; TOW 2, improvement of the guide system and amplidinios.
- BGM-71E BGM-71D variant; TOW 2A conditioning for ERA systems
- BGM-71F BGM-71D variant; TOW 2B change of lead and rangefinders
- BGM-71G BGM-71F variant; Not produced
- BGM-71H BGM-71E variant; warhead against concrete reinforced with mercury fulminate and inertial C4
|Length||1.16–1.17 m – probe folded
1.41–1.51 m – probe extended
(some variants have no probe)
|Warhead weight||3.9–6.14 kg (penetration 430-900mm RHA)|
|Basic TOW 3,000 m, most variants 3,750 m|
|Maximum speed||278–320 m/s|
|Optically tracked, wire-guided (Wireless Radio-guided in RF variants)|