Ladder: On shipboard, all stairs are called "ladders," except for literal staircases aboard passenger liners. Most "stairs" on a ship are narrow and nearly vertical, hence the name. From the Anglo-Saxon hiaeder, meaning ladder.
[Source: http://www.desertanchor.com/glossary.htm]
The space under a staircase is called a spandrel.
stringers
Handrails or bannisters
They are metalloids.
Bed room
the ships carrying emigrants were called "coffin" ships
The elements on the stair case are called metalloids.
Coffin ships were called coffin ships because lots of people died on them
Because they were ships? Do you mean longships? They were long and thin.
It is usually called a landing.
The decorative wood on a staircase is called "wainscot"
A ships accountant is called a "PURSER"