Coordination between each site was overseen by the Directorate of Technical Development (DTD) under Dr. Zaman Sheikh (a chemical engineer) and Hafeez Qureshi, a mechanical engineer. The DTD was established by Munir Ahmad Khan in 1974 at the Metallurgical Laboratory and was tasked with development of tampers, reflective and explosive lenses, optics, and triggering mechanisms that are crucial in atomic weapons. First implosion design was built by TPG in 1977 and the DTD eventually conducted the cold-test on 11 March 1983, codename "Kirana-I". Between 1983 and 1990, PAEC carried out 24 more cold tests of various nuclear weapon designs and shifted its focused towards tactical designs in 1987 that could be delivered by all Pakistan Air Force fighter aircraft.