A built-up frame to provide extra strength consisting of a web plate with flanges on its edges placed several frame spaces apart, with the smaller, regular frames in between.
Isakhelo esenzelwe ukunika inkxaso kubuphinyephinye bepleyiti enesangqa sentsimbi esidibanisa ezinye iintsimbi ekupheleni kwazo. Ithi ifake indawo ezininzi ezivulekileyo ngokwahlukeneyo, ze ibenezakhelo ezincinci nezilungeleleneyo.