Port Layout, Berths, and Waterfront Structural Design
Port layout converts cargo demand into geometry - berth length and depth, apron and yard, breakwater shelter - and into the structural system that carries ship, crane and cargo loads.
Berth geometry
- Berth length is roughly 1.1 × LOA of the design vessel plus 15–25 m of mooring and clearance allowance; a larger allowance may be needed where mooring is difficult.
- Water depth = maximum draught × (1.10–1.15) plus squat, under-keel clearance, siltation and wave allowance and dredging tolerance; for 14.5 m draught this lands near 16.5–17.5 m.
- Apron width must hold crane rails, backreach, truck lanes and hatch-cover storage: 40–50 m for ship-to-shore container cranes.
Terminal layout
- Crane outreach must cover the widest vessel at design heel; rail gauge and crane spacing fix the apron module and the yard transfer route.
- Yard capacity in TEU per hectare depends on stacking height and equipment: RTG stacks 4–5 high, straddle carriers 3–4, reach stackers fewer. Rough planning uses 20–25 ha per 1,000 m of quay.
- Berth productivity in moves per ship-hour is the real capacity driver; quay length alone overstates what a terminal can handle.
Structural systems
- Open piled jetties suit soft ground: deck on vertical and raking piles, with berthing energy absorbed by fenders rather than by the structure.
- Fender selection: berthing energy E = ½ mv² with added mass and eccentricity factors; the fender's rated energy at the permitted deflection must exceed design energy with margin.
- Mooring loads from wind and current are checked against bollard capacity and spacing for the design vessel, using standard OCIMF-type coefficients.
Worked example
Design vessel 366 m LOA, draught 15.5 m. Depth = 15.5 × 1.10 + 0.9 squat + 0.5 siltation = 18.45 m, rounded up to 18.5 m below chart datum. Berth length = 1.1 × 366 + 20 ≈ 423 m. At 28 moves per ship-hour and 1.2 million TEU per year at 60% occupancy: berth-hours required = 1,200,000/(28 × 0.6 × 8,760) ≈ 8.1, so a single berth is far too few - the layout must be phased across several berths.
Traps
- Computing depth from mean draught at neap tide rather than maximum draught at the design condition.
- Treating berth occupancy as a simple inverse of utilisation without allowing for arrival variability and ship waiting cost.