In case the space is not enough, you can use one more section in the hatchway, but leave a small margin. 如果舱位不够,你们可以在舱口位再用一节梁子,但要留一个小空档。
hatchway
[ noun ] an entrance equipped with a hatch; especially a passageway between decks of a ship <noun.artifact>
Hatchway \Hatch"way`\ (-w[=a]`), n. A square or oblong opening in a deck or floor, affording passage from one deck or story to another; the entrance to a cellar.