Xiamen Sugang Bridge Lighting Project

Project overview

An outdoor architectural lighting project for Xiamen Sugang Bridge, a major coastal infrastructure landmark in Fujian Province. The project required IP67-rated linear LED systems engineered for marine salt spray exposure, typhoon-level wind loads, extreme thermal cycling (-5°C to +55°C surface temperature), and motorist glare control — while creating a distinctive nighttime landmark silhouette visible across Xiamen Bay. Mihoray supplied corrosion-resistant linear LED fixtures with marine-grade driver enclosures and documented structural attachment engineering.

Client needs

• Distinctive nighttime landmark identity visible across Xiamen Bay at distances exceeding 2km
• Marine-climate durability withstanding salt spray, typhoon conditions, and coastal humidity cycling
• Controlled luminaire glare that does not impair motorist vision on the bridge deck or approach roads
• Maintenance strategy suitable for at-height access on bridge pylons and deck edges with intervals exceeding 5 years
• Structural attachment engineering documented for bridge authority approval without compromising structural integrity

Technical challenges

• Maintaining IP67 waterproof integrity at expansion joints where bridge structure moves up to ±25mm under thermal expansion and traffic loading
• Preventing accelerated corrosion of housings, connectors, and mounting hardware in marine salt air environment with >3mg/cm²/day chloride deposition
• Engineering luminaire photometry that creates landmark visibility from 2+ km while maintaining BUG (Backlight-Uplight-Glare) ratings compliant with roadway safety standards
• Designing maintenance access strategy for fixtures mounted at 15-40 meter heights on bridge pylons where access requires traffic control and specialized equipment
• Ensuring LED color stability after 30,000+ hours in an environment combining high UV exposure, salt spray, thermal cycling, and vibration from traffic

Mihoray solution

Project results

• Bridge nighttime silhouette visibility confirmed at 3+ km across Xiamen Bay — exceeding the 2km design target
• Zero waterproof failures or corrosion incidents after 18 months of continuous marine environment exposure including two typhoon seasons
• Motorist glare assessment passed by highway authority with comfortable margin — no reported visibility complaints from road users
• Maintenance inspection at 12 months confirmed all seal integrity and no measurable corrosion on housings or hardware
• LED color shift measured at <2 SDCM after 12 months continuous operation — within acceptable limits for long-term architectural consistency

Project background

Xiamen Sugang Bridge is a major coastal infrastructure crossing in Fujian Province, connecting districts across Xiamen Bay. As a prominent landmark visible from multiple viewing angles — including the Xiamen waterfront promenade, approaching vessels, and surrounding elevated roads — the bridge authority commissioned architectural lighting to establish a nighttime civic identity. The marine environment presents extreme challenges for lighting systems: chloride-laden salt spray accelerates corrosion, typhoon-season winds exceed 150 km/h, surface temperatures cycle from -5°C (winter nights) to +55°C (summer afternoon sun on steel deck), and ultraviolet exposure degrades many polymer materials within 2-3 years.

Design approach

Mihoray's engineering approach prioritized long-term durability over initial cost, recognizing that any maintenance intervention on a bridge requires traffic control measures costing significantly more than the lighting components being serviced. Every design decision was evaluated through a total-cost-of-ownership lens: marine-grade materials that cost 40% more initially but eliminate the need for 5-year replacement cycles; modular construction that allows individual fixture exchange without disturbing adjacent units; and over-engineered sealing that provides margin beyond the rated environmental exposure. The photometric design balanced three competing requirements: landmark visibility (high output toward water), roadway safety (controlled glare toward drivers), and environmental responsibility (minimal upward light waste). Asymmetric reflector geometries with secondary optic shields resolved all three requirements simultaneously.

Installation process

Bridge lighting installation required coordination with highway authority traffic management plans. All at-height work on pylons was performed using underbridge inspection units (UBIUs) during controlled traffic-flow periods. Mounting brackets were pre-engineered in collaboration with the bridge's structural engineer to attach at approved loading points without drilling new holes in primary structural members — all fixings use existing bolt positions or clamping systems. Linear fixtures were pre-assembled in 2-meter modules in Mihoray's facility, with all electrical connections and sealing completed under factory-controlled conditions. On-site work was limited to mechanical attachment and inter-module plug connections, minimizing time at height and eliminating field wiring that could compromise waterproof integrity.

Technical specifications

Product: Marine-Grade Linear LED Fixture, asymmetric optic. LEDs: High-power SMD, 48 LEDs/m. Power: 24W/m. Voltage: 48V DC (for long cable runs to drivers). CCT: 4000K neutral white. CRI: ≥80 (Ra). IP Rating: IP67 (fixture body and connectors). Housing: 6063 anodized aluminum + nano-ceramic coating. Hardware: 316L stainless steel with nylon isolation. Driver: IP67 marine-grade enclosure, surge protection 10kV. Optics: Asymmetric reflector, BUG B1-U0-G2 rating. Wind resistance: Designed for 180 km/h. Operating temperature: -20°C to +55°C (ambient). Module weight: <3kg/m for single-person handling. Expected lifespan: 60,000h L80. Certifications: CE, RoHS, IP67, salt spray test 2000h.

Project outcome

The Xiamen Sugang Bridge lighting project establishes Mihoray's expertise in marine-environment outdoor architectural lighting for infrastructure-scale projects. The combination of corrosion-resistant materials, expansion-tolerant sealing, motorist-safe photometry, and maintenance-efficient modular construction addresses the full spectrum of challenges unique to coastal bridge lighting. This project serves as a technical reference for bridge authorities, infrastructure contractors, and lighting consultants evaluating LED systems for marine-environment landmark structures where 10+ year service life between major maintenance interventions is expected.

Products used