1. Pre-Industrial (before the 19th century) 

Before the widespread use of electricity, cables and pipelines were supported in a more primitive way: 

Wooden or stone grooves: Early constructions (e.g., Roman aqueducts) used stone or wooden grooves to direct the flow of water, which can be seen as the prototype of bridges.

Simple metal supports: Before the Industrial Revolution, factories and mines used chains, hooks or simple brackets to hold steam pipes or ropes.

2. Driven by electrification and industrialisation (late 19th century - early 20th century) 

Demand for telegraph and power cables: In the mid-to-late 19th century, with the popularity of telegraph, telephone and power systems, the number of cables proliferated, and the traditional buried or overhead methods could no longer meet the demand.

Early metal raceways: In the 1880s, iron and steel mills began producing U-shaped or ladder-shaped metal raceways to support and protect cables.

Standardised production: At the beginning of the 20th century, the United States, Germany and other industrial countries began to develop standards for cable support systems, such as the U.S. NEMA (National Electrical Manufacturers Association) bridge specification.

3. Forming of modern bridge (mid to late 20th century) 

Material innovation: 

Steel bridge (galvanised, stainless steel) became the mainstream, corrosion-resistant and load-bearing capacity.

Aluminium alloy bridge (lightweight, corrosion-resistant) in the chemical industry, marine engineering is widely used.

Fiberglass reinforced plastic (FRP) bridge (insulation, explosion-proof) for special environments (such as petroleum, chemical industry).

Structure optimisation: 

Cable Ladder is suitable for large diameter cables.

Cable Tray for dense cabling.

Enclosed Tray provides better protection (dustproof, waterproof).

4. Intelligent and Future Trends (21st Century) 

Modular design: fast installation, expandable bridge system, adaptable to the needs of data centres, intelligent buildings.

Fire prevention and environmental protection: application of flame retardant, low smoke and non-halogen (LSZH) materials.

BIM (Building Information Modelling) Integration: digitalisation of bridge layout to improve construction efficiency.