Busan Transportation Corp. has completed field validation of a rigid overhead contact line system (R-bar) for direct-current sections — the first such application among Korea's urban railways — and will begin full-scale replacement of aging contact lines on Busan Metro Line 1.
The plan aims to overhaul the core power infrastructure of Line 1, which opened more than 40 years ago, using domestically developed technology while simultaneously improving urban railway safety and maintenance efficiency.
Busan Transportation Corp. said Thursday it had installed an R-bar system on a 140-meter test section of the Nopo inbound-outbound track on Busan Metro Line 1 and verified its stability under actual train operating conditions.
Contact lines are the core equipment supplying power to urban railway vehicles. Concerns over aging have been raised continuously for Busan Line 1, which has been in operation for more than 40 years since its opening in 1985.
The R-bar applied in this project is a rigid-type structure in which the contact wire is fixed to an aluminum alloy bar. It is typically used in confined spaces such as underground urban railway tunnels. While the existing compound catenary system suspends the contact wire in the air, R-bar fixes it directly to a rigid structure.
The corporation has been pursuing localization of DC 1500V R-bar technology since 2021 together with LS Cable & System as a national project led by the Ministry of SMEs and Startups, and succeeded in localizing the technology last year.
The existing system carried a relatively high risk of wire breakage due to continuous tension and required long restoration times after incidents. R-bar, by contrast, is structurally less prone to breakage and is comparatively easier to maintain and repair in emergencies.
Management efficiency is also expected to improve significantly. According to the corporation, the number of maintenance inspection items will be reduced to 34 from the current 52. Retrofit costs for underground tunnel sections are also expected to fall by about 30 percent compared with the existing method.
After completing field verification this year, the corporation plans to phase in replacement of contact lines across all underground sections of Busan Metro Line 1 by 2031, excluding the Dadaepo Beach extension. The work will begin with a 4-kilometer stretch between Beomeosa and Dusil next year.
"By replacing aging contact lines, we have laid the foundation for enhancing urban railway safety and maintenance efficiency," Busan Transportation Corp. President Lee Byung-jin said. "We will push ahead with the improvement project without disruption to ensure stable train operations."
