RIM-2 Terrier

The Convair RIM-2 Terrier was a two-stage medium-range naval surface-to-air missile (SAM), among the earliest SAMs to equip United States Navy ships. It underwent significant upgrades while in service, starting with beam-riding guidance with a 10-nautical-mile (19 km) range at a speed of Mach 1.8 and ending as a semi-active radar homing (SARH) system with a range of 40 nmi (74 km) at speeds as high as Mach 3. It was replaced in service by the RIM-67 Standard ER (SM-1ER).

Terrier has also been used as the base stage for a family of sounding rockets, beginning with the Terrier Malemute.

The Terrier was a development of the Bumblebee Project, the United States Navy's effort to develop a surface-to-air missile to provide a middle layer of defense against air attack (between carrier fighters and antiaircraft guns). It was test launched from USS Mississippi on January 28, 1953, and first deployed operationally on the Boston-class cruisers, Boston and Canberra, in the mid-1950s, with Canberra being the first to achieve operational status on June 15, 1956. Its US Navy designation was SAM-N-7 until 1963, when it was redesignated RIM-2.

For a brief time during the mid-1950s, the United States Marine Corps (USMC) had two Terrier battalions equipped with specially modified twin sea launchers for land use that fired the SAM-N-7. The Terrier was the first surface-to-air missile operational with the USMC. The launchers were reloaded by a special vehicle that carried two Terrier reloads.

Initially, the Terrier used radar beam-riding guidance, forward aerodynamic controls, and a conventional warhead. It had a top speed of Mach 1.8, a range of 10 nmi (19 km), and was only effective against subsonic targets. Originally, the Terrier had a launch thrust of 23 kN (5,200 lb_f) and weight of 1,392 kg (3,069 lb). Its original dimensions were a diameter of 340 mm (13 in), a length of 8.08 m (26.5 ft), and a fin span of 1.59 m (5.2 ft). The cost per missile in 1957 was an estimated $60,000.

Even before it was in widespread service, the Terrier saw major improvements. The RIM-2C, named the Terrier BT-3 (Beam-riding, Tail control, series 3), was introduced in 1958. The forward control fins were replaced with fixed strakes, and the tail became the control surface. The BT-3 also had a new motor and featured an extended range, Mach 3 speed, and better maneuverability. The RIM-2D Terrier BT-3A(N) entered service in 1962 with a W30^{[verification needed]}1kt nuclear warhead, but all other variants used a 218 lb (99 kg) controlled-fragmentation warhead. The Terrier had 2 versions: BT-3(N) and HT-3. Only the BT-3A carried the nuclear warhead, BT-3A(N).

When fired, and after booster separation, its corkscrew contrail progressed to the center of the beam. Reception of its location in the beam was accomplished by a small turnstile antenna at the rear of the missile; this antenna also received the commands for detonation and self-destruct. The self destruct-command was sent a few milliseconds after the detonation command. The HT-3 was a SARH missile; it followed the reflected energy from the target. However, if jamming was encountered, it would passively home in on the jamming signal.

The Belknap class of DLG, redesignated CG, also carried the ASROC (Anti Submarine Rocket), which was launched from the same launcher as the Terrier. The Belknap class had three circular magazines in a triangle pattern. The bottom magazine contained the nuclear BT-3A(N) missiles and the Nuclear Anti-Submarine Rocket (ASROC). This was an additional safety feature in that it involved transferring the nuclear missile from the bottom ring to the upper ring and then to the launcher rails, which entailed many moving steps and time, preventing the accidental loading of a nuclear missile from one of the top two magazines.