Tunnel Boring & Heavy Civil Equipment worked example

Disc Cutter Wear Rate at 68% target cutter survival rate: a worked example

This worked example runs the disc cutter wear rate numbers for a tougher week than the baseline: 68% target cutter survival rate instead of the typical 95%. Estimate disc cutter wear rate for tunnel boring and heavy civil equipment using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.

The inputs for this scenario

  • Disc cutters worn beyond limit: 8 count (held at the documented default)
  • Total disc cutters inspected: 250 count (held at the documented default)
  • Target cutter survival rate: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Disc cutter wear rate = disc cutter wear rate count ÷ total disc cutter wear rate population × 100.
  • Disc cutter wear rate works out to 3.2 % at these inputs, and this is the headline figure for the scenario.
  • Disc cutter wear rate gap to target works out to 64.8 points at these inputs.
  • Disc cutter wear rate count works out to 8 count at these inputs.
  • Total disc cutter wear rate population works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target cutter survival rate sits at 95% and the headline result is 3.2 %, this scenario lands almost exactly on the baseline at 3.2 %.
  • Use it after each cutterhead intervention or maintenance stop to quantify tooling consumption for the section of tunnel just excavated. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Disc cutter wear rate: 3.2 % (headline result)
  • Disc cutter wear rate gap to target: 64.8 points
  • Disc cutter wear rate count: 8 count
  • Total disc cutter wear rate population: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Disc Cutter Wear Rate calculator, set target cutter survival rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.