Mining Vehicle & Underground Equipment worked example

Weldment Fabrication Cost at 81% productive arc-time: a worked example

Push productive arc-time up to 81% and the picture changes. This example computes every intermediate figure at that operating point. A fabrication shop quoting the welded frame for a haul truck bed or underground loader before machining and assembly.

The inputs for this scenario

  • Welding labor hours: 120 hr (unchanged)
  • Loaded shop rate: 85 $/hr (unchanged)
  • Productive arc-time: 81 % (raised for this scenario; the documented default is 70)
  • Consumables and gas charge: 1,800 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Fabrication cost = welding hours x shop rate x productive arc-time % + consumables) to the inputs above produces each figure below.
  • At this operating point the engine returns 10,062 $ for total weldment fabrication cost, the number this scenario is built around.
  • At this operating point the engine returns 83.85 $ / piece for weldment fabrication cost per unit.
  • At this operating point the engine returns 8,262 $ for variable weldment fabrication cost.
  • At this operating point the engine returns 1,800 $ for fixed weldment fabrication cost adder.

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 12.55% above the baseline at 10,062 $.
  • Computes total weldment fabrication cost by multiplying welding labor hours by the loaded shop rate and productive arc-time percentage, then adding consumables and gas, and breaks out variable vs fixed cost. 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

  • Total weldment fabrication cost: 10,062 $ (headline result)
  • Weldment fabrication cost per unit: 83.85 $ / piece
  • Variable weldment fabrication cost: 8,262 $
  • Fixed weldment fabrication cost adder: 1,800 $

Run it with your numbers

  • Every input above is editable in the live Weldment Fabrication Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.