短語詞組短語swing boat davit 旋轉(zhuǎn)式艇架outreach of boat davit [船]吊艇架跨距luffing type boat davit 搖倒式艇架gravity -type boat davit 重力式吊艇架loading capacity of boat davit [船]吊艇架額定負荷 返回 boat davit