Introduction of Fire-Resistance Optical Fiber Cable for Railway Transportation 

With the increase in operation length, the corresponding demands for communication devices for rail transit keep increasing.

Optical cables are widely used in rail transit for their excellent safety, electromagnetic compatibility, reliability, multi-interfaces, and extensibility. Meanwhile, the security of rail transit has become more and more critical.

For the optical cables, the most severe accident is fire. Once the cable is damaged by fire, the communication might be interrupted, making it impossible to monitor the signals and control the essential devices, thus making it difficult for rescue, real-time monitoring, and equipment control.

Therefore, the communication cables are required to guarantee regular communication in the case of emergencies.

Based on flame-retardant & fire-resistant optical cables, ZION has developed optical cables for rail transit.

The cables can maintain regular communication and operation of critical equipment, send alarms and minimize losses caused by fire.

■ Product Series of Fire-Resistance Optical Fiber Cable for Railway Transportation

■ Classification

Non-metallic Protection

• GYFZY

  Fully non-metallic design, featuring a fire-resistant layer and flame-retardant sheath.

  It is suitable for environments where metal interference needs to be avoided, such as areas with high electromagnetic interference (EMI). 

Single Armor Design

• GYTZA

  Single APL (Aluminum-Plastic Laminate) armor with a single flame-retardant sheath.

  It is suitable for general railway line installations, offering basic mechanical protection and fire-resistance capabilities. 

• GYZS

  Single fire-resistant layer with single PSP (Steel-Plastic Composite) armor and a single flame-retardant sheath.

  Compared to GYTZA, it enhances both fire-resistance and mechanical strength.

Double Armor and Double Protection Design

• GYTZA53

  APL + PSP double armor with double flame-retardant sheaths. This design improves mechanical protection over GYTZA,

  making it suitable for harsher installation environments, such as underground or areas with high mechanical stress. 

• GYZS53

  Double fire-resistant layers with double PSP armor and double flame-retardant sheaths.

  This further enhances fire-resistance and mechanical protection, ideal for high-security-level railway communication systems.

Ultra-high Protection Design

• GYZS53+33

  Double fire-resistant layers, double PSP armor, additional single steel wire armor, and three flame-retardant sheaths.

  This design is suitable for extreme environments, such as tunnels, subways, or high-risk fire zones.

• GYFZA04+33

  Combines APL + steel wire armor + fire-resistant layer + anti-termite layer + flame-retardant sheath.

  In addition to fire and mechanical protection, it also offers pest protection, making it ideal for tropical and high-humidity railway environments.

■ Specific Application Scenarios

• For subway systems, tunnels, or hazardous railway environments → Choose GYZS53, GYZS53+33 (highest fire protection level). 

• For mountainous, underground railways, or high-stress areas → Choose GYTZA53 (double armor protection). 

• For areas with high electromagnetic interference or lightning protection needs → Choose GYFZY (fully non-metallic structure). 

• For regions with termites or high humidity → Choose GYFZA04+33 (anti-termite + fire protection).

■ Multiple Standard References

Railway Industry Standards

EN 45545-2

Material fire performance testing for railway transport systems, including optical cables, is the focus of this standard. Standards for cables that have this certification suggest that a cable with a high flame propagation, producing low smoke emissions, should be selected. Additionally, it must give off a minimum amount of toxic gas upon burning. 

• Applicable models: Safe, wires such as GYZS53 and GYZS53+33.

IEC 60331

Fire-resistance evaluation on these cables is done according to this standard, and any indication that they can pass the test should mean that the cables can also continue their transport of signals during a fire incident. These cables need to be very resistant in environments where fires are likely, such as tunnels and substations. 

• Applicable models: The wires should have a fire resistance layer, namely GYTZA53, GYZS and GYZS53.

GB/T 12666

Chinese standard for rail interface focuses on transport industry optical cables design, installation, and testing specifications. There must be provisions for fire exposure, mechanical resistance, and versatility towards environmental elements. 

• Applicable models: Most cables for railways including GYFZY, GYTZA, and the GYZS series.

Optical Cable Industry Standards

IEC 60794

Determining all the technical requirements and laying out the optical cable testing protocol is the work of this standard. It contains the examination for the physical toughness, capabilities to function in varied climate, and adequateness of the cable in case of fire. This technique guarantees that this cable can outplay extreme weather conditions such as high temperatures, wetness, which demands great resiliency. 

• Applicable models: All models like GYFZY, GYPTA53, GYZS53 and so on that demand the durability in extreme environments.

IEC 60332

The cable flammability is covered by this standard. It determines how the cable is burning and verify the compliance of the cable with the regulations to prevent flame propagation and ensure smoke generation is minimized. 

• Applicable models: GYFZY, GYZS53 and GYTZA53 must be in compliance with the fire-resistance standards.

RoHS

Environmental regulations compliance of the optical cables is ensured by the Restriction of Hazardous Substances Directive is through restricting hazardous materials such as lead, mercury, cadmium and chromium. 

• Applicable models: RoHS applicable for all models, GYFZY, GYTZA, GYZS, GYZS53.

Other Related Standards

UL 1581

This standard in the United States ensures that optical cables continue functioning and maintain their safety in addition to their mechanical and electrical properties even when under high temperatures and/or fire situations. 

• Applicable models: High-protection cables like GYZS53, GYTZA53 and wires classified as fire-resistant.

NF F 61-100

French standards are applied for high voltage data cables that are to be installed over ground and underground in areas filled with tunnels and highly dangerous conditions. 

• Applicable models: Wires conforming with fire protection regulations like GYZS53 and GYZS53+33.

Summary 

Fire-resistance and mechanical protection: Models such as GYZS53, GYZS53+33 are approved by EN 45545-2 and IEC 60331 requirements for a high-length railway environment. 

Durability and environmental adaptability: Electrical standards IEC 60794 and IEC 60332 are to make sure cables like GYFZY, GYTZA, and GYZS53 withstand tough physical conditions and fire hazards. 

Environmental compliance: The standards of RoHS and UL 1581 are applicable for cables like GYTZA and GYFZY. These cables are in compliance with international environmental and safety requirements.