Flush manholes are of two types: one to be applied in outer decks and BHD with a cover thickness of 18mm and one with an extra thick cover of 26mm to be applied in the tank top.
Flush manholes are of two types: one to be applied in outer decks and BHD with a cover thickness of 18mm and one with an extra thick cover of 26mm to be applied in the tank top.
平置人孔分两种,一个用于露天甲板和舱壁,厚度18mm,另一种是非常厚的26mm用于内底,
不知道是不是这个意思