How do you calculate derated lift capacity?

Multiply moves per cycle by available cycles for gross capacity, then multiply by availability and first-pass rate. Here 4 x 480 x 90% x 97% gives 1,676 good moves.

What is the difference between gross and good capacity?

Gross capacity (1,920 moves) assumes every cycle runs and lands cleanly; good capacity (1,676) subtracts 192 moves lost to downtime and 51.8 lost to first-pass failures.

What is a good crane availability figure?

Well-maintained ship-to-shore cranes target 90% or higher; the 90% used here is a realistic planning figure, and each point below it erases available cycles directly.

Why does first-pass yield matter for cranes?

Every misplacement, twistlock hang-up, or aborted lift is a move that consumed a cycle but did not count. At 97% first-pass, about 51.8 of the 1,920 gross moves are lost to rehandles.

How much capacity do the losses cost?

In the example, downtime removes 192 moves and yield issues remove another 51.8, so gross 1,920 becomes deliverable 1,676 — a combined 12.7% derating.

Should I plan to gross or good capacity?

Always to good capacity. Committing a stowage plan to 1,920 moves when only 1,676 are realistically deliverable is how berth windows slip and vessels wait.

Port, Crane & Terminal Equipment calculator

Lift Capacity Derating Calculator

Lift Capacity Derating calculates the realistic, deliverable move capacity of a crane over a period after downtime and first-pass-success losses are subtracted from the gross theoretical throughput. Terminal planners and equipment managers use it to set honest berth productivity targets rather than quoting nameplate capacity that never survives contact with real availability and rehandle rates. Gross capacity assumes every cycle runs and every move lands cleanly; derating strips out the cycles lost to breakdowns and the moves lost to misplacements, twistlock faults, or aborted lifts. The result is the number planners should actually commit to a vessel stowage plan.

What this calculator does

Estimate lift capacity derating for port, crane and terminal equipment using production-ready inputs so teams can confirm whether capacity can cover demand before committing the schedule.
Use it when lift capacity derating in port, crane and terminal equipment is being asked to take on more work and you need to know if there is room.
It computes gross capacity from moves per cycle and available cycles, then derates it by availability and first-pass success to give deliverable good-move capacity.

Formula used

Gross lift capacity derating capacity = lift capacity derating output per cycle × available lift capacity derating cycles
Good lift capacity derating capacity = gross capacity × expected lift capacity derating uptime × expected lift capacity derating first-pass yield

Inputs explained

Containers moved per crane cycle:
Available crane cycles in the period:
Expected crane availability:
Expected first-pass move success rate:

How to use the result

Use it when setting berth productivity targets or committing crane capacity to a vessel schedule, so promises reflect real losses.
It uses single average figures for availability and first-pass rate; it does not model hour-by-hour variation, operator fatigue late in a shift, or weather stoppages that cluster losses.

Current U.S. benchmarks

U.S. housing starts run at 1,177k per year (Census, May 2026), down 8.7% from a year earlier, the demand driver for building products.
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate derated lift capacity? Multiply moves per cycle by available cycles for gross capacity, then multiply by availability and first-pass rate. Here 4 x 480 x 90% x 97% gives 1,676 good moves.
What is the difference between gross and good capacity? Gross capacity (1,920 moves) assumes every cycle runs and lands cleanly; good capacity (1,676) subtracts 192 moves lost to downtime and 51.8 lost to first-pass failures.
What is a good crane availability figure? Well-maintained ship-to-shore cranes target 90% or higher; the 90% used here is a realistic planning figure, and each point below it erases available cycles directly.
Why does first-pass yield matter for cranes? Every misplacement, twistlock hang-up, or aborted lift is a move that consumed a cycle but did not count. At 97% first-pass, about 51.8 of the 1,920 gross moves are lost to rehandles.
How much capacity do the losses cost? In the example, downtime removes 192 moves and yield issues remove another 51.8, so gross 1,920 becomes deliverable 1,676 — a combined 12.7% derating.

Last reviewed 2026-05-12.