Bridge (cable tray) is a structural system used for supporting, protecting and laying cables, which is widely used in construction, electric power, communication, chemical industry and other fields. According to the different materials, structures and uses, the bridge can be divided into many types. The following are the common classification and characteristics:

1. Classification according to material

Steel bridge

Characteristics: high strength, good fire resistance, but need anti-corrosion treatment (such as galvanised, sprayed plastic).

Uses: industrial plants, substations and other strong electrical environment.

Stainless steel bridge

Characteristics: corrosion-resistant, high temperature-resistant, high cost.

Uses: chemical industry, ocean and other corrosive environments.

Aluminium alloy bridge

Features: lightweight, corrosion-resistant, good conductivity, but the strength is lower than steel.

Uses: data centres, communication rooms and other weak power systems.

Fibreglass Reinforced Plastic Bridge (FRP)

Features: insulation, corrosion resistance, light weight, but poor impact resistance.

Uses: acid and alkaline environments (such as sewage treatment plants).

Plastic bridge (PVC/PE)

Features: insulation, low cost, but low temperature resistance and strength.

Uses: light cable laying or temporary works.

2. Classified by structural form

Ladder type bridge

Structure: The cross-file is in the shape of a ladder, with good ventilation and heat dissipation.

Usage: large diameter cables or high heat dissipation demand scenarios (such as power cables).

Tray type bridge

Structure: flat plate at the bottom, both sides with edge, strong protection.

Usage: Commonly used for cable laying in buildings (e.g. shopping malls, office buildings).

Trough type bridge

Structure: fully enclosed metal slot box, dustproof, anti-interference.

Usage: Precision equipment or places with high shielding requirements (such as data centres).

Grid-type bridge

Structure: metal grid, open design, lightweight and flexible.

Use: integrated wiring system (such as optical fibre, weak power cable).

Combined Bridge

Structure: Flexible assembly of different components (e.g. tray + cover).

Use: complex laying requirements of the project.

3. Classification by function

Ordinary bridge

Standard structure, no special protection function.

Fireproof bridge

The surface is coated with fireproof paint or fire-resistant materials are used (e.g. fireproof channel box).

Usage: fire-fighting lines, high-rise buildings.

Anti-corrosion bridge

Material or coating resistant to corrosion (e.g. galvanised, stainless steel).

Shielded Bridge

With metal shielding layer, anti-electromagnetic interference (EMI).

4. Classified according to installation method

Suspended: hanging from the ceiling or bracket.

Wall-mounted: fixed on the wall.

Floor-mounted: installed on the ground or in the cable trench.