Chimodzi mwazinthu zodziwika bwino za mkono wa rock wa Kaiyuan womwe umayikidwa pa chofufutira cha Hitachi 1200 ndikutha kuteteza injini yayikulu.
Rock Arm, ngati mkono wosinthika wamitundu yambiri, ndi yoyenera kumigodi popanda kuphulika, monga migodi ya malasha otseguka, migodi ya aluminiyamu, migodi ya phosphate, migodi ya golide ya mchenga, migodi ya quartz, etc. Ndiwoyeneranso kukumba miyala yomwe ikukumana nayo pomanga zomangamanga monga zomangamanga ndi migodi yapansi, monga, miyala yamtengo wapatali, miyala yamtengo wapatali, mchenga wonyezimira. zotsatira, zida zamphamvu zamphamvu, kulephera kochepa, kulephera kwamphamvu kwambiri poyerekeza ndi nyundo zothyoka, ndi phokoso lochepa. Rock Arm ndiye kusankha koyamba kwa zida popanda kuphulika.