open railing

This can have open railings or be enclosed in glass, or a combination.

A circular metal staircase with an open railing of tubes led up to the gunhouse.

They had wandered into a more sheltered area, where the open railings were replaced by bulkheads on either side.

The railings in Louis Kahn buildings tend to be parapets, but where he is obliged to use an open railing the design is as simple as possible.

Perhaps the simplest open railings are those of the great Adirondack camps, whose builders mimicked X-shaped wrought-iron railings in unpeeled rustic tree trunks.