The U.S. Navy began its development of sea-launched cruise missiles in 1972. The program aimed to provide a ship and submarine-launched missile for attacking ship and land targets. In 1975, General Dynamics was awarded a contract for their ‘Tomahawk’ design. More than 35 years later, the 2,000th Tomahawk cruise missile was fired during the Libyan mission, Operation Odyssey Dawn.

Tomahawk Block IV TLAM-E shown in flight.

Since the 1970s, numerous variants have been produced. The Block I versions included the Tomahawk Land Attack Missile-Nuclear (TLAM-N, TLAM-A, RGM/UGM-109A) and the Tomahawk Anti-Ship Missile (TASM, RGM/UGM-109B). Block II variants include the TLAM-C (RGM/UGM-109C), designed to attack hardened targets; and the TLAM-D (RGM/UGM-109D) designed to attack ‘soft’ targets such as aircraft and troop concentrations. Block III updates included new electronics allowing for coordinated attacks. Block IV missiles, the most modern version, are capable of loitering in flight for hours and possess a two-way datalink designed for receiving updated mission information of course corrections.

 Block I

There were two original Tomahawk designs; The nuclear-tipped TLAM-N and the conventional munitions TASM.

TLAM-N

When nuclear Tomahawk missiles were conceived, they were seen as another dimension to strengthen deterrence. The U.S. already possessed silo-based intercontinental ballistic missiles (ICBMs), bombers/air-launched missiles, and submarine-launched ballistic missiles (SLBMs). Even though the TLAM-N were submarine-based, creating redundancy with SLBMs, the flight trajectory was much different than ballistic missiles. This added dimension and potentially complicated defense planning for the Soviet Union.

Tomahawk missile shown at launch.
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The U.S. Navy originally planned to buy 758 TLAM-N missiles, but only 367 were produced. By 1991, President George Bush announced that TLAM-N missiles would be placed in storage. Almost twenty years later, the Obama administration’s Nuclear Posture Review (2010) moved to eliminate the TLAM-N.

All of the Tomahawk variants are 5.55 m in length (without booster), 0.5172 m in diameter, 1,315 kg in weight (without the booster), and can travel at M0.72. TLAM-N missile is capable of carrying a W80 200 kT nuclear warhead 2,500 km. The missile is guided by a combination of inertial navigation and TERCOM. The TLAM-N is estimated to have an accuracy of 80 m CEP.

BGM-109G Gryphon

The BMG-109 Gryphon (Sometimes called Griffin) is a road-mobile, ground-launched, variant of the well known Tomahawk series of cruise missiles. Development began in the early 1970s, and it became operational in 1984. Several years later the INF Treaty was signed and ratified which banned intermediate-range ground-launched cruise missiles. The system was completely destroyed by 1991 in accordance with the treaty provisions. ¹

BGM-109G Gryphon TEL vehicle.

This Ground-Launched Cruise Missile (GLCM) had a range of 2,500 km and could reach speeds of approximately 800 kph. ² The missile was 6.4 m in length, 0.52 m in body diameter, and 1,470 kg in launch weight. The Gryphon carried a single W-84, 10 to 50 kT nuclear warhead. The missile utilized inertial navigation and TERCOM. The United States deployed 322 missiles aboard 95 TEL vehicles. There were also 121 non-deployed missiles and 28 TELS.

TASM

The TASM is the anti-ship variant equipped with an active radar seeker, rather than TERCOM. TASM (and other versions except the TLAM-N) carries a 454 kg warhead. Compared the TLAM-N, the range is significantly shorter at 460 km.

The TASM was a very agile missile capable of various flight patterns. It could fly high altitude (up to 450 m) or low altitude trajectories; it could fly a ‘sea-skimming’ route; or a pop-up high-angle dive in the terminal phase.

In 1994, all TASM missiles were removed from warships and later converted to Block IV versions.

Block II

In late 1970s, the U.S. Navy sought a precision land attack cruise missile capable of a much smaller CEP. Two Block II versions were produced including the TLAM-C and the TLAM-D.

TLAM-C

The primary role of the TLAM-C was to destroy or inhibit large, hard targets. The TLAM-C carried a 454 kg warhead capable of targeting naval bases and airfields. The TLAM-C was used extensively in Operation Desert Storm. Official numbers indicate that over 300 Block II variants were fired, including 27 TLAM-D missiles. During Gulf War (1991), Tomahawks achieved an 85 percent success rate.

An upgrade for the TLAM-C was completed in 1986, which introduced the Digital Scene Matching Area Correlation (DSMAC) navigation system, designed for the TLAM-C and TLAM-D versions. The Block 2 version has a range of 1,300 km when ship-launched, and 925 km when submarine-launched. The accuracy was dramatically improved to less than 10 m CEP.

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TLAM-D

The TLAM-D has the same guidance and accuracy as the TLAM-C, but it is designed to strike softer targets such as aircraft and air defenses. The TLAM-D was originally equipped with a Combined Effects Bomblets (CEB) submunitions warhead that consisted of 166 small armor piercing, fragmentation and incendiary devices. The payload could be released against three targets in succession. The CEB warhead is no longer used and has been replaced with a fragmentation unitary warhead.

The TLAM-D has three terminal flight trajectories. It could fly horizontally into the target; it could dive vertically into the target; or, it can detonate directly over the target. ³

TLAM variant shown in a horizontal impact.
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Block III

Block III upgrades included a combination of mechanical and technological improvements. These included the following:

• Reduced the time required for mission planning from 80 hours to one hour with the introduction of a GPS navigation system. Unfortunately, this prevented the mission from being modified mid-flight. ⁴
• The ability to loiter over targets while waiting for other assets to arrive.
• New turbofan which uses three percent less fuel, and produces 20 percent more thrust.

Block IV

The Block IV TLAM-E is the most modern, operational variant of the Tomahawk series of land attack cruise missiles. The TLAM-E was designed to maintain the high accuracy of previous versions, while increasing the flexibility and operational control. Prior Tomahawks were often fired in groups to ensure that the target would by neutralized. The other missiles often struck a pile of rubble, thus wasting an average of one million per missile. The TLAM-E is capable of being redirected to other targets by a two-way datalink. This is increasingly important as more countries invest in TEL vehicles capable of what is often called “shoot and scoot.” ⁵ Other important improvements include:

• Increased range to 1,600 km.
• Improved high anti-jamming GPS system.
• An electro-optic sensor capable of damage assessment.

Approximately 3500 Tomahawk missiles have been ordered or delivered since production began in the 1980s. The Block IV is the only version still manufactured. Most of the other Tomahawk variants have been, or will be, converted to the Block IV capability. ⁶