Mining Vehicle & Underground Equipment worked example

Weldment Fabrication Cost at 50% productive arc-time: a worked example

This worked example runs the weldment fabrication cost numbers for a tougher week than the baseline: 50% productive arc-time instead of the typical 70%. Estimate the cost to fabricate a heavy steel weldment such as a dump-truck frame or LHD chassis for mining and underground equipment.

The inputs for this scenario

  • Welding labor hours: 120 hr (held at the documented default)
  • Loaded shop rate: 85 $/hr (held at the documented default)
  • Productive arc-time: 50 % (the input this scenario stresses; the baseline uses 70)
  • Consumables and gas charge: 1,800 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Fabrication cost = welding hours x shop rate x productive arc-time % + consumables.
  • Total weldment fabrication cost works out to 6,900 $ at these inputs, and this is the headline figure for the scenario.
  • Weldment fabrication cost per unit works out to 57.5 $ / piece at these inputs.
  • Variable weldment fabrication cost works out to 5,100 $ at these inputs.
  • Fixed weldment fabrication cost adder works out to 1,800 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where productive arc-time sits at 70% and the headline result is 8,940 $, this scenario comes in 22.82% below the baseline at 6,900 $.
  • Use it when quoting a fabricated mining weldment, validating a subcontractor's labor estimate, or comparing in-house fabrication against an outside buy. 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

  • Total weldment fabrication cost: 6,900 $ (headline result)
  • Weldment fabrication cost per unit: 57.5 $ / piece
  • Variable weldment fabrication cost: 5,100 $
  • Fixed weldment fabrication cost adder: 1,800 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Weldment Fabrication Cost calculator, set productive arc-time to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.