The BOMA engines from Indonesia were the only model powerplants ever to enter series manufacture in that country. They came into existence through the efforts of one man, Mr. Tan Hien Tjong, who was a member of the local model flying club in Pasuruan on the Island of Java. Mr. Tjong was employed at the nearby State-owned P. M. BOMA heavy engineering works. He wished to do something to make model engines available to his fellow Indonesian modellers, since the importation of such engines was prohibited by government regulations.
In 1960 Mr. Tjong somehow came into possession of an example of the 1956 Russian-made MK-12S 2.5 cc diesel. After securing the permission of his employers to use their equipment after hours during his spare time, he made a small number of copies of this model. In recognition of the support received from his employer, he named the engine the BOMA 250. A photograph of this model was featured in the November 1960 issue of "Aeromodeller" magazine.
The evident success of this unit encouraged Mr. Tjong to commence the development of his own home-grown designs. In 1964 he commenced production of a 1.5 cc plain bearing reed valve diesel which he called the BOMA 150. This was followed in 1969 by a 3.2 cc plain bearing front rotary valve diesel called the Tiga Serangkai (Series Three) 35 model, shortened to T.S. 35. It is unclear why the BOMA name was dropped from this model - perhaps the support of Mr. Tjong's employers had been withdrawn. Regardless, both of these designs were featured in articles by the ever-knowledgeable Peter Chinn.
In 1970 or shortly thereafter, Mr. Tjong disappeared, never to be heard from again. It appears likely that he fell victim to the widespread persecution of Indonesian residents of Chinese extraction which took place during this period. Many fled to China, but others were killed by mobs. Mr. Tjong's fate is unknown.
A more complete account of the BOMA venture may be found elsewhere on this website. My thanks to Swedish enthusiast Sten Persson for the provision of much of the above information.
