Design and Verification of Class B₁ (d₀, t₀, a₁) Cables for Rail Transit Ring Networks

In an urban rail transit power supply system, the reliability of rail transit ring network cables is decisive for the entire line. Given the varying conditions of different lines, an investigation into laying methods and operational requirements for these cables was conducted. Based on the investigation, the design and calculation of metal shielding cross-sectional area for a specific cable were introduced. Furthermore, technical processes were employed to achieve critical properties, including waterproofing, rodents and insects resistance, UV resistance and flame retardancy. Performance tests confirmed that all key indicators met relevant standards, providing a solution for rail transit ring network cables, featuring waterproofing, rodent and insect resistance, UV resistance and flame retardancy of Class B₁ (d₀, t₀, a₁).