lattice-bar

from The Century Dictionary.

• noun In structural work, particularly bridge work, one of the slender diagonal members which connect the two opposite parallel members or flanges of a structural iron or steel beam, column, or strut, and which are arranged in two or more distinct, continuous, zigzag lines, the bars of one line crossing those of the other: in distinction from lacingbars, which form a single, continuous, zigzag line, no two members of which cross one another.