Bang Fai (the Rockets)
Jaruat (Thai: จรวด) is the proper term for rockets used as missiles or weapons, but Bang Fai (Thai: บั้งไฟ) skyrockets are gigantic black-powder bottle rockets. Tiny bottle rockets are so-called because they may be launched from a bottle. In the case of the similar appearing Bang Fai, also spelled 'Bong Fai' (Thai: บ้องไฟ), the 'bottle' is a bong (Thai: บ้อง), a section of bamboo Culm used as a container or pipe (and only colloquially as a pipe for smoking marijuana.)
Related to the Chinese Fire Arrow, Bang Fai are made from bamboo bongs. Most contemporary ones, however, are enclosed in pvc piping, making them less dangerous by standardizing their sizes and black powder charges (which contest rules require be compounded by the rocketeers, themselves). Baking or boiling a bong kills insect eggs that otherwise hatch in dead bamboo and eat it, inside out. Skipping this step may cause the bong to disintegrate and melt the pvc piping. Vines tie long bamboo tails to launching racks. The time it takes for the exhaust to burn through the vines (usually) allows a motor to build up to full thrust; then the tails impart in-flight stability. Ignition comes from a burning fuse or electric match.
Bang Fai come in various sizes, competing in several categories. Small ones are called Bang Fai Noi (Thai: น้อย). Larger categories are designated by the counting words for 10,000, 100,000 and 1,000,000: Meun (Thai: หมื่น) "Saen" (Thai: แสน) and the largest Bang Fai, the Lan (Thai: ล้าน). These counting words see use in many contexts to indicate increasing size or value. Lan in this context may be taken to mean extremely large as well as extremely expensive and extremely dangerous: Bang Fai Lan are nine metres long and charged with 120 kg of black powder. These may reach altitudes reckoned in kilometers, and travel dozens of kilometers down range (loosely speaking, as they can go in any direction, including right through the crowd). Competing rockets are scored for apparent height, distance, and beauty of the vapor trail (Thai: ไอ). A few include skyrocket pyrotechnics. A few also include parachutes for tail assemblies, but most fall where they may.
Read more about this topic: Rocket Festival