High Quality Content by WIKIPEDIA articles! The Singapore Self-Propelled Howitzer 1 (SSPH 1) Primus is a self-propelled howitzer armed with a 155 mm howitzer. Developed jointly by the Singapore Armed Forces (SAF), Defence Science and Technology Agency (DSTA) and Singapore Technologies Kinetics (ST Kinetics), it was introduced to the Singapore Artillery in 2004. Primus is derived from the motto of the Singapore Artillery In Oriente Primus (Latin: "First in the East").