a new method of sending corrections to the missile that was far easier for the gunner to use, especially against moving targets. Vigilant went on to see widespread use in several nations including the United States. Swingfire and TOW The basic idea of under-cover fire remained of interest, and the Royal Armament Research and Development Establishment (RARDE) was given £250,000 a year to continue research into the basic concepts. As part of the resulting Project 12, they developed two basic concepts, Quickfire and Swingfire. The former appears to be a fast-action weapon, but few details have been made public. The latter was designed to allow it to be fired from under cover, like Orange William. As the company already had experience in the indirect fire role, and fearing it would otherwise lead to the breakup of their missile team, Fairey was issued a new development contract in October 1959. The basic idea of the Swingfire concept was that thrust vectoring of the rocket exhaust allowed the missile to make extreme maneuvers, including a right-angle turn immediately after launch. This was especially useful in urban settings like Berlin; the gunner could take the sight up to from the launcher and position themselves along potential lines of approach, while the launcher parked down a side street or alleyways. The missiles could be fired without the launcher ever exposing itself to the enemy, and the gunner could easily remain hidden in a foxhole or building. While the rocket smoke would still give away the rough location of the launcher, the enemy would be unable to return fire. As the Warsaw Pact greatly increased its number of tanks during the 1960s, the long-range missile was once again considered important. The Soviet plan was to simply overrun NATO forces using sheer numbers, so a weapon that could attrit these forces before they reached friendly forces was highly desirable. The US Army was equally interested in such a system, and in July 1961 the two countries signed the Rubel-Zuckerman Agreement for further development. Under this plan, the US would concentrate on short-range rapid-fire weapons, while RARDE would continue Swingfire development for the long-range role. Of the several concepts studied in the US, the BGM-71 TOW was ultimately selected. TOW used a semi-automatic guidance system that was very easy to use and capable of easily tracking moving targets, but had limited accuracy in long-range use and had