Originally Posted by HolySmoke
Steel drum used here for most UDS builds are 22.5" (571mm) x 34.5 (876mm) 55 gallon steel drum. You might reconsider your sizing on products
height of ash box, burner and umbrella is 250 mm, effective hight above umbrella is 876-250=620mm. My skewer height is 500m. You can have two bars as PBC to hang the skewers. There are two meat hooks on each skewer. I think the length of skewer of 500 mm is good.
Air inlet duct shall be 160 mm to make the ash box in center. 150mm shall be OK too. Leave space on other side of ash box 170mm.You can place a water bowl there
The size of burner and ash box need to be tested and optimized. If you add 1" lining on walls of UDS by ceramic clay, the burner shall be big enough for 10+ hours at 225F.
The first picture is a UDS made from kitchen soap barrel, 17 1/2" x 17 1/2"
stainless steel, wall thickness 1.5 mm, or gauge 17