Cruise control: successful launch sees UK ready for Tomahawk Block IV missile

At precisely 0913 h local time on 21 June 2007, a submarine-launched Tomahawk Block IV cruise missile slammed into a simulated target site at the Eglin Air Force Base (AFB) land test range, Florida, concluding a 650 n mile test flight begun in the Gulf of Mexico 75 minutes earlier.

Discharged from one of the five torpedo tubes in the bow of HMS Trenchant, a UK Royal Navy (RN) Trafalgar-class nuclear-powered attack submarine (SSN), the missile had broached, transitioned to cruise flight, and then navigated to its target using a combination of GPS updates and digital scene-matching area correlation. Arriving in the target area, it entered a terminal dive to impact within inches of its intended aimpoint.

British Flight Test [BFT] 8 was an outright success, and paves the way for the Torpedo Tube Launch (TTL) Tomahawk Block IV variant to enter service with the RN during the first half of 2008. But while the flight test was just one hour and 15 minutes in duration, the journey that culminated in a pinpoint strike at the Eglin AFB range has been somewhat longer and more difficult than stakeholders on both sides of the Atlantic had foreseen. In particular, a series of TTL Tomahawk test failures required Raytheon Missile Systems, as lead developer and manufacturer, to conduct a root-and-branch review of the Block IV design, re-engineer parts of the missile, and make significant improvements in production quality control.

The RN remains the only service outside the US Navy (USN) to have acquired the Tomahawk cruise missile, introducing the Block IIIC variant of the weapon into service aboard appropriately configured SSNs from December 1998. Just four months later, HMS Splendid, operating submerged in the Adriatic, became the first RN unit to use Tomahawk in action, employing its newly acquired capability for precision strike from the sea as part of NATO's intervention Operation 'Allied Force' against Serbian military forces in Kosovo.

Significantly, the UK did not procure just the weapon and its associated submarine fire-control system. It has also bought into the USN's entire mission-planning infrastructure, being fully interoperable to the extent that target files and mission-planning data can be exchanged seamlessly between US and UK cruise missile support authorities.

Following Kosovo, the RN has subsequently fired an undisclosed number of Tomahawk missiles (reliable sources suggest more than 100) in campaigns in Afghanistan and Iraq. What the evidence of the last eight years suggests is that although the RN Tomahawk programme was originally justified on the basis it offered a long-range precision strike capability by which to exercise high-level 'coercive' diplomacy, it is now accepted as a weapon of genuine tactical utility.

This is certainly the perception of the USN, and is reflected by the development of the latest Tomahawk Block IV marque, conceived as the Tactical Tomahawk. Designed to meet requirements for a more responsive and flexible capability, the Tactical Tomahawk concept was developed jointly by Raytheon and the USN to improve effectiveness against time-critical targets, while at the same time significantly reducing the cost of the all-up-round. 510 of 1,865 words