Ọrụ nke Castle aku bụ idozi ihu na azụ axle nke ụgbọ ahụ site na ịtọgharị ihe nkedo site na ihu ihu ihu na azụ azụ, nke mere na etiti ahụ na taya ahụ na-edozi ọnụ. Iji gbochie nut si ịtọghe, Ga-eji ntụtụ pin site na oghere nut uzo bụ ofu, na cotter pin jide oghere nut ga-abụ site na etiti aro ịghasa, aro ịghasa na-emekarị mkpa egwu, ma dayameta nke oghere na oghere nut ka size nke oghere obosara, na ihe size nke gbawara n'etiti pin uzo omimi ekpebi nhọrọ, a hoputara na aro ịghasa na gbawara n'etiti pin na oghere nut na-kenha, aku site aro ịghasa jide n'ihu wheel na etiti, gbawara ntụtụ oghere site na ihe nkedo ihe nkedo, nkpuru ahihia, mee ka ahihia ahu ghara, ghara imeputa ugbo ala n'oge mmega ahu adighi.
