1. Project Background & Critical Challenges
Geographical & Load Profile:
50km route connecting Tokyo CBD and Yokohama industrial zone, traversing high-density urban areas, soft coastal soil, and seismic zones.
Peak load: 2,700MW with N-1 contingency requirement (per TEPCO standards).
Environmental Constraints:
Corrosion: Coastal salt spray (Yokohama) + industrial pollution (SO₂ >0.1ppm).
Space Limitation: Compact hardware design required for urban tower foundations.
Seismic Demand: Hardware shear resistance ≥ Intensity 8 (Japan seismic code).
2. SH Power Solution
2.1 High-Strength Corrosion-Resistant Components
Bolt Systems:
BM34 Series HDG Bolts: Tensile strength 30,000 lbs, rolled threads for fatigue resistance. Passed ISO 1461 500h salt spray test.
Custom -C1.5 Low-Temp Version for Yokohama: Impact toughness ≥27J @ -50°C.
Anchoring Hardware:
GUY CLAMP JS930: Dual-sleeve design for 3/16-7/16″ strands. Anti-slip force >225 lbs/100pcs. Solved soft-soil anchoring.
AS80WBNC Anchor Shackle: Wide-body (Dim A=3.75″), 80,000 lbs ultimate strength. Reduced foundation load by 30%.
2.2 Conductor Fixing & Insulator Interface
| Hardware Type | Model | Technical Features | Project Fit |
|---|---|---|---|
| Deadend Clamp | DC-130-35 | Aluminum body + ductile iron keeper, 35,000 lbs ultimate strength | 40% lighter vs conventional, suited for confined spaces |
| Suspension Clamp | SC16225 | Grooved conductor channel, 25,000 lbs clamping force, anti-galloping | Suppressed conductor oscillation (>15m/s in Tokyo Bay) |
| Insulator Link | BC50 Ball Clevis | Forged steel, ANSI 52-8 ball socket, 50,000 lbs strength | Compatible with composite insulator S348104VX |
2.3 Seismic & Redundant Design
Anti-Loosening Mechanisms:
BNC34 Concave Locknut: Mechanical lock with 1/2-turn wrench torque. Passed JISC 1252 seismic test (0.5g acceleration).
SRW34 Spring Washer: Compensates wood shrinkage. Preload retention >90% (tested).
Redundancy:
Critical nodes use BOEDA3420 Double Arming Eye Bolt (20,050 lbs strength) for mechanical redundancy.
3. Engineering Value Validation
Corrosion Life: HDG coating >86μm (exceeds JIS H8641). Zero corrosion reports in Yokohama after 8 years (TEPCO 2023 inspection).
Installation Efficiency: Modular hardware (e.g., SATC106 suspension clamp) reduced aerial work time by 40%, shortening schedule by 15 days.
Failure Rate: Annual hardware failure <0.02 incidents/100km (industry avg: 0.1).
Conclusion
SH Power provided fully customized line hardware with high-strength anti-corrosion materials, seismic locking, and compact designs for Tokyo-Yokohama. Achieving zero main-grid hardware failures under extreme conditions, it sets an industry benchmark for urban transmission in East Asia.
