The M-220 TOW Missile System

The TOW missile system is a U.S. designed series of anti-armor missiles and launchers. TOW is an acronym for Tube-launched, Optically-tracked Wire-guided. Variants of the TOW are used by infantry teams, on HMMWVs, on the Bradley Fighting Vehicle, the U.S. Marine Corps Improved Fighting Vehicle (IFV), on the Army Improved Tow Vehicle and on the Bell AH-1 Cobra attack helicopter platform. It has been supplanted on the AH-64 Apache by the newer Hellfire missile.

How it works

The TOW missile and launcher are fairly large. Although they can be lifted by an infantryman, they really need a team of two or three to move about and operate properly. They can be fired and directed either from a standalone launcher or as part of a system on a carrying vehicle. When used by foot soldiers, the launcher must first be erected and then loaded with a prepackaged missile canister. In vehicles, the missiles are placed in their racks prior to leaving base, and the guidance systems are wired into the vehicle's display/tracking systems.

When a TOW operater spots a target, he or she attempts to bring the target into view through a spotting scope attached to the launcher (or coaxial with it in a vehicle). Once the target is in the crosshairs, the range is checked; the TOW has a range of around 3.75km. If the target is in range, and at a good aspect, the round is fired. The missile is actually ejected from the launcher by a small pyrotechnic charge to avoid damaging the launcher and (more importantly) the operater from backblast; when it is several feet away from the launcher, its guidance fins have rotated out and locked into position. At this point, a sustainer motor rocket fires, propelling the missile towards its target.

The missile remains connected to the launcher through a pair of very fine wires, which unspool from a reel mounted in the missile canister. Guidance commands are sent through the wires, and can cause the control surfaces on the missile to deflect, changing its course. The obvious question, of course, is how does the guidance work?

It's actually a very elegantly simple idea. The operator looks through the spotting scope (or at a display attached to one) which has a crosshairs on it. His or her job is to keep the crosshairs centered on the target vehicle at all times. The missile itself shows up on the scope as well, as an enormous IR flare emitted by the rocket motors. To be sure it's visible, and to avoid confusion when there are multiple hot spots in view, the missile also carries an IR beacon which flashes back towards the launcher. The basic concept is that of a feedback loop. In addition to the operator, the guidance system 'looks' through the scope as well. It attempts, through the sending of guidance commands, to keep the hot spot of the missile exhaust centered bang onto the crosshairs. Therefore, as long as the crosshairs are on the target, the missile will fly there.

The most common problem with operating the TOW is that the operator will have to fight a natural urge to 'steer' the missile by overcorrecting and moving the crosshairs off the target ('past' it from the missile's POV). Since the missile is not responding to directional control movements but rather attempting to remain centered in the scope, such attempts at steering are doomed to fail.

The U.S. made several variants of these, from plain anti-tank to more sophisticated radar-tracking versions. The TOW 2A was introduced with a new warhead and logic set designed to defeat reactive armor. There is a follow-on, the TOW 2B, which will replace it. All earlier versions have been decommissioned from the U.S. armed forces. The missile is coproduced under license by Switzerland, however, so there are still supplies of the early Marks of the missile on the world arms market.

TOWs were first used in Vietnam in 1972. They performed quite well in Desert Storm as well, and continue to be the system of choice to give unarmored or lightly-armored vehicles an anti-armor capability. One advantage that they have over guns is that they can be fired from cover, if you have a decent idea of where your target is. They are also heavy enough to carry a large shaped charge warhead (HEAT) which makes up for their slow speed. Newer versions carry infrared night vision spotting scopes, allowing them to be used at night and in poor visibility. Finally, TOW 2Bs have been designed for 'improved lethality,' which this analyst takes to mean that they have a top-attack capability.

The missile system has been produced by (at various times):

  • Hughes Aircraft
  • Philco Ford Defense
  • ...and many other component contractors
Here are some basic specs from FAS.
  • Manufacturer: Hughes (missiles); Hughes and Kollsman (night sights); Electro Design Mfg. (launchers)
  • Size: TOW 2A Missile:
    • Diameter: 5.87 inches (14.91 cm)]
    • Length: 50.40 inches (128.02 cm)]
  • TOW 2B Missile:
    • Diameter: 5.8 inches (14.9 centimeters)
    • Length: 48.0 inches (121.9 centimeters)
  • Warhead weight 12.4 kg
  • Maximum effective range: 2.33 miles (3.75 kilometers)
  • Armor penetration: T-80 + / 800+ mm >700 mm
  • Time of flight to maximum effective range:
  • 2A: 20 seconds
  • B: 21 seconds
  • Weight:
    • Launcher w/TOW 2 Mods: 204.6 pounds (92.89 kilograms)
    • Missile Guidance Set: 52.8 pounds (23.97 kilograms)
    • TOW 2 Missile: 47.4 pounds (21.52 kilograms)
    • TOW 2A Missile: 49.9 pounds (22.65 kilograms)
    • TOW 2B Missile: 49.8 pounds (22.60 kilograms)
  • Introduction date: 1970
  • Unit Replacement Cost: $180,000