Duke Frederick's portable firepit

Duke Frederick of Holland of the West Kingdom shares his portable firepit design, which has been "approved for use at any site which permits the use of hibachis by the West Kingdom Fire Marshall." The online tutorial includes instructions with diagrams.

From the article:

The general design is shown to the left. It is a bowl which is a segment of a sphere suspended on a tripod which runs through holes in the bowl. In the bowl is a flat fire-grate made of expanded metal which holds the fire off the base of the bowl, keeping it cool and allowing a place for ashes to fall. The tripod additionally supports the grill on which you cook, or can be used to suspend a pot above the fir. The bowl is constructed of six fan-shaped plates which pivot on a central bolt and latch together with hooks to form a rigid structure. The fans are overlapped so that there are no open gaps through which coals might fall to the ground.