Gantry Crane Reeling Cable — High-Speed Outdoor Drum Cable for STS, RTG, and Shipyard Portal Crane Power, Control, and Fiber Optic Transmission

Gantry Crane Reeling — The Most Demanding Cable Application

A gantry crane — particularly an STS (ship-to-shore) container crane — subjects its reeling cable to a combination of stresses that no other industrial application approaches:

1. Speed: 120 m/min main hoist — 2 m/s cable speed on the drum, 24 hours a day, 7 days a week
2. Load: The cable must carry its own weight over a 50+ m lift height, plus dynamic acceleration loads when the spreader picks up or sets down a 40-ton container
3. Environment: Direct sun, salt spray, rain, and wind on an exposed dock with zero weather protection
4. Cycles: 200 000+ reeling cycles over a typical 5–7 year cable life — 100+ cycles per day
5. Combined signals: Power for the main hoist motors + control signals for limit switches and brakes + fiber optic for crane management system (CMS) and remote diagnostics — all in one cable

A gantry crane cable failure is not a maintenance inconvenience. It stops a container terminal. At $2 000–5 000 per hour in lost terminal productivity, the cost of a cable failure far exceeds the cost of the cable itself.

Three Crane Types — Three Cable Requirements

STS (Ship-to-Shore) Container Crane

• Power: Main hoist 6/10 kV or 0.6/1 kV (depending on crane generation), 95–400 mm²
• Lift height: 35–55 m above quay, 15–20 m below quay (total 50–75 m)
• Control: 12–36 cores for spreader, brakes, limits, and auxiliary functions
• Fiber: 6–12 fibers SM for CMS, OCR (optical character recognition), and remote diagnostics
• Environment: Direct marine exposure — salt, UV, wind
• Special requirement: The cable must handle the transition from vertical hoist movement to horizontal trolley movement without twisting

RTG (Rubber-Tired Gantry) Crane

• Power: 0.6/1 kV, 35–95 mm² (diesel-electric) or 6/10 kV (all-electric)
• Lift height: 15–18 m (1-over-5 container stacking)
• Control: 12–24 cores for gantry drives, steering, and spreader
• Fiber: 6 fibers for CMS and yard management system interface
• Environment: Outdoor container yard — dust, sun, rain, occasional salt spray (coastal terminals)
• Special requirement: Cable reel mounted on the crane structure, moving with the crane — wind and vibration loading on the reel mechanism

Shipyard Portal Crane

• Power: 0.6/1 kV, 50–185 mm² — heavy-lift capability for ship blocks
• Lift height: 30–80 m depending on vessel size
• Control: 12–24 cores for multiple hoists and trolley functions
• Fiber: 6–12 fibers — increasing in modern cranes for automation
• Environment: Coastal shipyard — salt, welding fumes, abrasive grit from blasting
• Special requirement: Very high lift heights → very heavy cable → very high tensile demand on steel core

Fiber Optic Integration — The Modern Requirement

Every new gantry crane installation now includes fiber optic in the reeling cable. The optical fibers carry:

• CMS data: Load cells, motor temperatures, bearing vibration — continuous condition monitoring
• OCR and automation: Container number recognition and automated crane positioning data
• Remote diagnostics: Crane manufacturer access for troubleshooting without site visits
• Yard management: Real-time container inventory and position data to terminal operating system

The fibers are integrated into the cable's core assembly in a gel-filled stainless steel loose tube:

• Stainless steel tube: Provides crush resistance and hydrogen barrier for the fibers
• Thixotropic gel filling: Prevents water ingress along the tube if the cable jacket is damaged
• Excess fiber length (EFL): The fibers are slightly longer than the tube — allowing the tube to stretch under cable tension without straining the fibers
• Bend-insensitive fiber (G.657): Single-mode fiber optimized for the tight bend radii of reeling applications

Why Choose Yichi Cable Gantry Crane Reeling?

• Crane OEM experience: We supply to major crane manufacturers — our cables are designed to their specifications, not generic catalog products
• Fiber optic integration: Our in-house fiber cabling capability means the fiber elements are integrated during cable manufacturing — not added as an aftermarket modification
• Combined cable engineering: We design the complete cable — power + control + fiber — as one integrated assembly. Conductor sizing, core arrangement, and tensile reinforcement are calculated for the combined cable weight
• Marine certification: DNV GL, ABS, and Lloyds certification available — required for many port and shipyard installations
• Global port references: Our gantry crane cables are operating in major container terminals worldwide — proven in 24/7 service