Mining Equipment

Costing and Quoting Mining Vehicle and Underground Equipment

What actually drives cost per unit on mining vehicles and underground equipment, how to build a defensible quote, and where estimates quietly go wrong.

Cost per unit on mining vehicles and underground equipment splits roughly into material at 35 to 45 percent, direct labor at 25 to 35 percent, machine time and burden at 12 to 20 percent, and scrap, rework, and overhead making up the rest. A 6-tonne LHD frame weldment can land anywhere from 18,000 to 32,000 dollars depending on how those shares are estimated. The trap is quoting from weight alone; two frames of identical mass differ by thousands once weld volume, coating area, and machining are counted. Build the quote from the physical drivers, then layer margin, rather than scaling last year's price by a steel index.

Weldment cost is driven by deposited weld metal, not plate mass. S355 plate runs 0.90 to 1.30 dollars per kilogram, but each kilogram of deposited weld metal costs 40 to 70 dollars once you include wire, gas, and arc labor. A frame needing 22 kg of deposit at 55 dollars adds 1,210 dollars in welding alone. Arc-on time is the killer variable: welders run only 20 to 30 percent of clocked hours actually striking arc, so 22 kg at a 4 kg/h deposition rate is 5.5 arc-hours but 20 or more paid hours. The Weldment Fabrication Cost calculator separates deposition from clocked labor so the quote survives scrutiny.

Direct labor is set by loaded rates and honest hours. A certified welder loaded with benefits, supervision, and consumables costs 45 to 75 dollars per hour; a mechanical assembler 38 to 60 dollars. Drivetrain integration alone can run 30 to 45 hours per unit, and pulling that number from the Drivetrain Assembly Hours output keeps the estimate tied to the learning curve rather than a flat guess. Estimators go wrong by pricing the prototype build; by unit 10 on a 90 percent curve, hours fall roughly 25 percent, and quoting the first-article time on a repeat order can overprice a bid by 8,000 to 12,000 dollars per machine.

Coating and dust sealing are underrated line items. Underground machines get abrasive-blasted to SA 2.5 then coated with a 3-coat epoxy and polyurethane system at 250 to 350 microns, costing 8 to 18 dollars per square meter in material plus 6 to 12 dollars in labor. A frame with 40 square meters of surface can carry 900 to 1,200 dollars in coating. The Paint and Coating Cost calculator prices by area and coats, while the Dust Protection Cost calculator covers sealing, filtration, and cab pressurization on electrical enclosures, which alone can add 2,000 to 5,000 dollars on a machine bound for a dusty heading.

Scrap and rework quietly erode margin. Weld NDT reject rates of 3 to 8 percent are normal, and each rejected joint costs grind-out plus reweld, often 1.5 to 3 hours at full loaded rate. Budget a rework allowance of 4 to 6 percent of fabrication labor rather than pretending yield is perfect. Cutting scrap on plate nesting typically runs 8 to 15 percent by weight; tightening nesting to 10 percent on a machine using 3,200 kg of plate saves roughly 160 kg, or 190 dollars at 1.20 dollars per kilogram. Small per unit, but real across a 40-machine build.

Machine time and overhead need explicit rates, not a blanket markup. CNC plasma and laser cutting bill at 2 to 5 dollars per minute all-in; a frame with 90 minutes of cutting carries 180 to 450 dollars before a single part is welded. Machining bores and mounting faces adds 60 to 140 dollars per hour of spindle time. Roll shop overhead, energy, cranes, and QA into a burden rate of 20 to 35 percent on direct labor rather than hiding it in material markup, so that when a customer challenges the number you can show which cost pool each dollar sits in.

Life-cycle cost extends past the shop door. Spare parts inventory carries at 18 to 28 percent of stock value per year in holding, obsolescence, and capital, so a 400,000 dollar crib costs 72,000 to 112,000 dollars annually; the Spare Parts Inventory calculator sizes stock against demand and lead time. A warranty or commissioning quote should include a field service buffer for travel, standby, and callbacks, commonly 5 to 12 percent of contract value, sized with the Field Service Buffer calculator. For electrified fleets, fold the Battery-Electric Retrofit Payback result into total cost of ownership before committing to a diesel-only price.

Quotes fail on the same handful of misses: assuming 40 percent arc-on time when the shop runs 25, omitting freight on a 6-tonne frame that can cost 3,000 to 8,000 dollars to move underground-ready, ignoring tariff and alloy surcharges that swing steel 10 to 20 percent quarter to quarter, and forgetting the derating that comes when a machine is built for a hot, deep heading. Anchor every quote to measured hours, current material invoices, and the calculators above, then hold a documented margin. A number you can trace line by line wins more repeat work than the lowest bid.

Published 2026-07-02.