AA autocannons. Moreover, their lack of protection rendered them highly vulnerable to improvised explosive devices (IEDs) or small-arms fire, and many were lost together with their crews in 1979 due to intense street fighting and ambushes in rural areas. Commandeered tracked Caterpillar or wheeled civilian Bulldozers of American and Spanish origin were also employed by the Guardia during the battles for Masaya and Managua to clear paths on rebel-held urban neighbourhoods by demolishing buildings turned into bunkers by the guerrillas. Order of battle as by 1978–79 Ground Forces In January 1978 National Guard overall strength peaked at about 25,000 officers and enlisted men under the direct personal command of their Chief Director and President of Nicaragua Major general Anastasio Somoza Debayle (a.k.a. 'Tachito'). Often described as something closer to a corps of feudal retainers (or an occupation force) than to a modern national army, the GN was primarily organized for internal security and Counter-insurgency (COIN) operations rather than national defense, with most infantry units being assigned static garrison duties, and consequently its conventional military value was very low. Out of this total some 10,000–12,500 served in the ground forces proper (including women in the military and PNGN), but only about 7,500 were combat troops, organized into one Presidential Guard battalion, one armoured battalion, one mechanized infantry battalion, one mechanized company, one engineer battalion, one Military Police battalion, one field artillery battery and one anti-aircraft battery, plus sixteen security companies. All the aforementioned units were deployed in traditional Spanish colonial fashion in fortress-like cuarteles (Quarters; barracks-cum-garrisons) in the main cities, including the national capital of Managua. The Headquarters of the GN's General Staff was placed at the heart of the government quarter of Tiscapa Hill near downtown Managua, allocated in an underground bunker-style complex built after the 1972 Nicaragua earthquake; the quarter's adjacent facilities also housed the main offices' of the Guardia's own administration, signals, engineering, medical, logistics and military justice support services, and the main military schools. Managua was also home to most of the GN's main tactical units such as the Batallón de Guardia Presidencial (BGP, Presidential Guard Battalion), the Patrulla Presidencial (PP, Presidential VIP protection unit), the Primero Batallón Blindado (PBB, 1st Armoured Battalion), the Batallón de Combate General Somoza (BCGS, General Somoza Combat Battalion), the Batallón de Ingeniería (Engineer Battalion), the Batallón de Policía Militar (BPM, Military Police Battalion), and the Artillery Batteries. The Compañías de Seguridad