Seaport Container Berth Throughput Calculator

This calculator estimates how much container volume a single berth can handle (in TEU per day and per year) and how many vessel calls that berth can support, based on ship-to-shore crane productivity, operating hours, and the fraction of time the berth is actually occupied by a working vessel. It is intended for quick capacity checks and “what-if” planning by terminal operators, port authorities, and consultants—not as a substitute for a full berth, yard, labor, and marine services simulation.

What the calculator outputs

• Daily TEU throughput: the estimated TEU moved across the berth per day, given your inputs.
• Annual TEU throughput: daily throughput scaled to a 365-day year.
• Vessel calls per day/year: an estimated number of ship calls supported, using your average TEU per vessel call input.

Core idea

At a high level, berth throughput is driven by two levers:

1. Gross working rate when a vessel is alongside (how many container moves your cranes can complete per hour).
2. Effective working time (how many hours per day you operate, and what share of that time the berth is actually occupied by a vessel with active operations).

Formulas used

Let:

• c = number of ship-to-shore cranes assigned to the berth
• m = average moves per crane per hour (moves/hour/crane)
• h = operating hours per day (hours/day)
• o = berth occupancy (as a decimal, e.g., 70% → 0.70)
• S = average TEU exchanged per vessel call (TEU/call)

Daily TEU throughput is estimated as:

Annual TEU throughput is:

T_y = T_d × 365

Vessel calls per day is estimated by dividing daily TEU by the typical exchange per call:

V_d = T_d ÷ S

Annual vessel calls is:

V_y = V_d × 365

How to interpret each input

• Number of ship-to-shore cranes: The average number simultaneously working the berth when a ship is alongside. If crane assignment varies by vessel size, use a weighted average for your typical call mix.
• Average crane moves per hour: A practical, sustained average (not a peak). If you have separate “gross” and “net” crane rates, use the rate that best matches how you define occupancy (see limitations below).
• Operating hours per day: Scheduled operations window. For 24/7 terminals use 24; otherwise use your planned daily working hours.
• Berth occupancy (% of time a vessel is present): The fraction of the operating day during which the berth is occupied by a vessel and productive work is occurring. This is the biggest “reality check” factor: it captures gaps between vessels, berthing/unberthing, and non-productive periods you choose to include.
• Average TEU per vessel call: The typical TEU exchange per call (load + discharge), averaged across your service strings/call sizes.

Worked example

Assume the following:

• c = 2 cranes
• m = 30 moves/hour/crane
• h = 24 hours/day
• occupancy = 70% → o = 0.70
• S = 5,000 TEU/call

Daily TEU throughput:

T_d = 2 × 30 × 24 × 0.70 = 1,008 TEU/day

Annual TEU throughput:

T_y = 1,008 × 365 = 367,920 TEU/year

Vessel calls per day:

V_d = 1,008 ÷ 5,000 = 0.2016 calls/day

Vessel calls per year:

V_y = 0.2016 × 365 ≈ 73.6 calls/year

Scenario comparison (quick sensitivity)

The table below shows how throughput changes when you adjust one major driver at a time, using the worked example as the baseline.

Interpreting results (and avoiding common misreads)

• Throughput is not the same as “design capacity.” The calculator is a simplified berth-side estimator. Real terminal capacity is often constrained by yard density, truck/rail gates, labor availability, marine services, and weather.
• Occupancy and crane moves/hr must be consistent. If your moves/hr figure already accounts for breaks/delays (a “net” rate), then occupancy should represent time with a vessel alongside (not productive time). If your moves/hr is closer to a “gross while-working” rate, then occupancy should reflect the productive fraction of the day.
• TEU per call is an average exchange, not vessel size. Two ships of the same nominal capacity can have very different exchanges depending on transshipment share, import/export balance, and schedule integrity.
• Use the vessel-call outputs as directional. Dividing TEU/day by TEU/call assumes exchange volume is smooth and divisible; in practice, calls arrive in lumpy windows and require berth windows and tug/pilot availability.

Assumptions & limitations

• One “move” ≈ one TEU for estimation. In reality, containers may be 20ft (1 TEU) or 40ft (2 TEU), and twin-lift or tandem operations can change the relationship between “moves” and TEU moved.
• No explicit allowance for crane interference or vessel length constraints. Adding cranes may not scale linearly on shorter vessels due to crane interference, hatch cover work, and stowage access limits.
• Ignores yard and gate constraints. Even if berth cranes can achieve the calculated throughput, yard equipment, stack capacity, and gate/rail operations can cap sustainable volume.
• Occupancy is treated as an exogenous input. In real operations, occupancy is the outcome of arrival patterns, call size variability, berth windows, weather, and productivity. Very high occupancy targets (e.g., >80–85%) can increase waiting times and disrupt schedules.
• Maintenance and weather are simplified. You can represent them indirectly by reducing moves/hour or reducing occupancy, but the model does not separately simulate planned maintenance, wind stops, or labor stoppages.
• Uniform day-to-day operations. Annual values are computed by multiplying by 365; the model does not account for seasonality, peak weeks, or holiday staffing patterns.
• Average TEU per call is assumed stable. If your service mix changes (larger ships, different strings, more transshipment), update S and, ideally, also crane assignment and moves/hour.

If you need planning-grade results, treat this calculator as a first-pass screen, then validate with historical berth logs (productive vs non-productive time), a vessel-call distribution (not just an average), and yard/gate capacity checks.