Port, Crane & Terminal Equipment worked example

Lift Capacity Derating at 99% expected crane availability: a worked example

Push expected crane availability up to 99% and the picture changes. This example computes every intermediate figure at that operating point. 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.

The inputs for this scenario

  • Containers moved per crane cycle: 4 units / cycle (unchanged)
  • Available crane cycles in the period: 480 cycles (unchanged)
  • Expected crane availability: 99 % (raised for this scenario; the documented default is 90)
  • Expected first-pass move success rate: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross lift capacity derating capacity = lift capacity derating output per cycle × available lift capacity derating cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good lift capacity derating capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross lift capacity derating capacity.
  • At this operating point the engine returns 19.2 units for lift capacity derating downtime loss.
  • At this operating point the engine returns 57.02 units for lift capacity derating yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where expected crane availability sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • 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. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Good lift capacity derating capacity: 1,844 units (headline result)
  • Gross lift capacity derating capacity: 1,920 units
  • Lift capacity derating downtime loss: 19.2 units
  • Lift capacity derating yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Lift Capacity Derating calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.