Tunnel Boring & Heavy Civil Equipment worked example

Torque Capacity at 65% drive availability: a worked example

Suppose drive availability falls to 65%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate torque capacity for tunnel boring and heavy civil equipment using production-ready inputs so teams can confirm whether capacity can cover demand before committing the schedule.

The inputs for this scenario

  • Cutterhead torque delivered per rotation: 4 units / cycle (held at the documented default)
  • Available cutterhead rotations in the window: 480 cycles (held at the documented default)
  • Drive availability (uptime): 65 % (the input this scenario stresses; the baseline uses 90)
  • First-pass boring effectiveness: 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross torque capacity = torque capacity output per cycle × available torque capacity cycles.
  • Good torque capacity works out to 1,211 units at these inputs, and this is the headline figure for the scenario.
  • Gross torque capacity works out to 1,920 units at these inputs.
  • Torque capacity downtime loss works out to 672 units at these inputs.
  • Torque capacity yield loss works out to 37.44 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where drive availability sits at 90% and the headline result is 1,676 units, this scenario comes in 27.78% below the baseline at 1,211 units.
  • It multiplies torque delivered per rotation by available rotations to get gross capacity, then discounts it by drive uptime and first-pass boring effectiveness to yield usable capacity. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Good torque capacity: 1,211 units (headline result)
  • Gross torque capacity: 1,920 units
  • Torque capacity downtime loss: 672 units
  • Torque capacity yield loss: 37.44 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Torque Capacity calculator, set drive availability to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.