Ladder may refers to cable ladder. Ladder is used to support large number of large cables between two points. Cable Ladder material shall be selected based on environmental and installation conditions. Several types of material are available such as stainless steel, GRP, galvanized steel.
Metallic cable ladder shall be furnished with grounding equipment to avoid static electricity stored on the ladder. Ladder shall be protected with cover for installation where there is possibility of fallen objects ( liquid spill, debris, etc.) on the ladder that may impair the cable.
Besides supported by ladder, cable may also be support by tray or by channel for fewer number of cable.
Below picture shows cable ladder picture.