Port, airport and terminal planning and operations
This domain tests capacity arithmetic and bottleneck reasoning for container terminals, air cargo and passenger terminals: you should be able to convert throughput into berths, yard slots, gates and aircraft movements.
The capacity chain
A terminal is a chain of constrained resources: berth and quay cranes, horizontal transport, yard stacking, gate and rail. Capacity of any link = rate × time × utilisation. Berth productivity is quoted in moves per vessel-hour; a move is one crane cycle, not one TEU (a twin-lift move may handle two). Yard requirement follows Little's Law, L = λW, applied in TEU-days.
Worked example
A terminal handles 6.0 million TEU/yr with average container dwell of 4 days and an average stack height of 5 TEU per ground slot.
- TEU-days in yard = 6,000,000 × 4 = 24,000,000 per year.
- Average TEU in yard = 24,000,000/365 ≈ 65,753.
- Ground slots required = 65,753/5 ≈ 13,151.
If dwell falls to 3 days, slots fall to about 9,863 - a 25% release of land with no change in throughput. That is why dwell time is a planning lever, not just an operational statistic.
Vessel example: a 14,000 TEU ship exchanging 60% of capacity (8,400 moves) with 6 cranes at 32 moves/h and 88% utilisation gives 6 × 32 × 0.88 = 169 moves/h, so about 50 hours alongside - assuming no hatch-cover or crane-split losses, which a good answer states explicitly.
Airports
Runway capacity depends on fleet mix, wake-turbulence separations and taxi routeing; declared capacity is expressed in movements per hour and allocated through slot coordination (IATA Level 3 at congested airports). Terminal planning uses space standards per passenger and level-of-service bands (IATA ADRM) for check-in, security, immigration and baggage reclaim; baggage system capacity is driven by peak-hour bags and sortation rate.
Traps that cost marks
- Confusing TEU with moves, or annual throughput with peak-day throughput.
- Using average dwell without recognising import/export/transhipment dwell differences.
- Ignoring gate and berth-window peaks and landside access.
- Quoting design capacity without utilisation or availability assumptions.