1. Primary Anchorage Specifications
| Designation | Position (±5m) | Dimensions | Depth Below CD | Seafloor Composition | Max Occupancy | Design DWT | Special Provisions |
|---|---|---|---|---|---|---|---|
| Gaosha Outer A1 | 22°12’34″N 113°04’56″E | 2,200m × 1,700m | 18.5-22.1m | – Upper layer: Soft clay (SPT N=8) – 2m depth: Stiff silty clay (N=17) – Friction angle: 25° per CPT |
6 vessels (min 500m spacing) |
300,000 MT | – Typhoon mooring pattern required – Dedicated VLCC swing circle |
| Xinhui Chemical C4 | 22°07’50″N 113°00’30″E | 1,100m × 950m | 11.5-13.2m | – Homogeneous clay (PI=28) – Undrained shear strength: 45kPa – Sensitivity St=2.1 |
4 vessels (min 300m spacing) |
50,000 MT | – Vapor barrier mandatory – Bonded repair team standby |
2. Hydrodynamic Conditions
| Parameter | Gaosha A1 | Xinhui C4 | Measurement Standard |
|---|---|---|---|
| Tidal Range (MHWS-MLWS) | 3.2m (max 3.8m springs) | 2.6m (max 3.1m springs) | MSA Tide Tables 2024 Vol.3 |
| Peak Current Velocity | – Flood: 2.8kts @285°T – Ebb: 3.2kts @105°T |
– Flood: 2.1kts @250°T – Ebb: 2.5kts @070°T |
ADCP Surveys 2023 (MSA-HYD-234) |
| Wave Climate (1-year storm) | – Hsig: 2.4m – Tp: 6.8s – Direction: SSE |
– Hsig: 1.8m – Tp: 5.2s – Direction: SE |
ERA5 Reanalysis Data 2024 |
3. Anchor Holding Capacity Analysis
| Anchor Type | Gaosha A1 (kN) | Xinhui C4 (kN) | Test Methodology |
|---|---|---|---|
| AC-14 (10t) | 3,200 (5:1 scope) | 1,850 (5:1 scope) | DNV-RP-E301 App.B |
| Stevin (12t) | 4,100 (6:1 scope) | 2,300 (6:1 scope) | OCIMF Mooring Equipment Guidelines |
| Safety Factor | 1.67 (ULS condition) | 1.82 (ALS condition) | IMO MSC.1/Circ.1455 |
4. Operational Services
| Service Provider | License Number | Capacity | Response Commitment |
|---|---|---|---|
| Zhuhai Salvage (Towing) | MSA-T-4402 | – 6,000HP ASD tugs (2 units) – 80t bollard pull |
30min at QRF status |
| Sinopec Bunkering | MOT-F-7715 | – 5,000m³ bunker barge – ISO 8217:2023 compliance |
12hr advance notice required |
5. Navigational Warnings
- Gaosha A1: UXO clearance completed 2023-09 (MSA Notice JM2023-45)
- Xinhui C4: Submarine cable corridor (500m exclusion)
- All anchorages: Squall warning system activated May-October
