Cost Estimation

Port Crane Cost Estimation: Pricing Steel, Welding, Paint, and Commissioning

A bottom-up view of what actually drives cost on fabricated crane and terminal equipment, and the estimating errors that quietly eat margin at handover.

Cost per crane, or per fabricated subassembly, in port equipment breaks into six buckets: steel material, welding, mechanical and electrical assembly labor, surface protection, testing, and spares. On a mid-size STS crane in the 900 t to 1,300 t steel range, material and welding alone run 45 to 55 percent of ex-works cost. A defensible quote prices each bucket from measured quantities, not a lump-sum guess. The Crane Weldment Cost, Paint Coverage Cost, Control Cabinet Assembly Time, Cable Reel Labor, FAT Workload, Field Commissioning Cost, and Spare Parts Buffer tools each target one bucket. Miss one and margin evaporates at handover.

Steel is the largest single line. S355 plate landed cost sits around 900 to 1,300 USD per tonne depending on grade, thickness, and market. A 1,100 t crane at 1,050 USD/t is 1.155 million USD before a single cut. Add cutting drop and offcut scrap, typically 8 to 15 percent on plate-heavy structures, so buy 1,210 to 1,265 t to net 1,100 t. Price scrap recovery back at 150 to 250 USD/t. The classic error is quoting on net weight and forgetting the drop, which quietly adds about 10 percent to the material line and shows up only when purchasing places the order.

Welding is priced per kg of deposited weld metal, not per meter of joint. Crane Weldment Cost multiplies weld volume by 7.85 g/cm3, then divides by deposition rate. A single box girder can hold 3,500 to 6,000 kg of weld. At a realistic FCAW deposition rate of 4.5 kg/hour including duty cycle, 5,000 kg needs 1,111 arc hours. At a loaded shop rate of 55 USD/hour that is 61,100 USD in labor, plus flux-cored wire near 2.20 USD/kg with 5 percent spatter and stub loss, about 11,550 USD in consumables. Assuming a 60 percent duty cycle when reality is 30 to 35 percent doubles the true hours.

Electrical and mechanical assembly is quoted in standard hours times a loaded rate. Control Cabinet Assembly Time counts terminals, devices, and wire runs: a large drive cabinet with 800 terminations at about 6 minutes each is 80 hours, plus 20 percent for testing and dressing. Cable Reel Labor covers pulling and terminating festoon or reeling cable: 600 m of 4-core power cable at 12 m per labor hour is 50 hours before glanding. At 48 USD/hour those two lines alone reach roughly 8,640 USD per crane. Estimators who count devices but skip wire dressing and continuity checks understate these lines by 15 to 25 percent.

Surface protection carries three costs: abrasive blast, paint material, and application labor. Blasting to Sa 2.5 runs 4 to 7 USD/m2 including grit and disposal. Paint material follows the spreading rate from Paint Coverage Cost; at 6,100 L and 14 USD/L that is 85,400 USD. Application labor for three coats on structural steel averages 0.10 to 0.18 hours per m2, so 8,000 m2 across three coats is 2,400 to 4,320 hours. The frequent miss is quoting theoretical coverage instead of practical, which ignores the 30 percent loss factor and leaves the paint material line 25 to 40 percent short.

Testing and commissioning are labor and logistics, not material. FAT Workload sizes the shop test: a full functional and load test on an STS crane runs 3 to 6 crew for 5 to 10 days, so 150 to 480 man-hours plus load-test rigging. Field Commissioning Cost adds travel, per diem, and site time: a two-person team for 4 weeks at 1,200 USD/day loaded, plus 8,000 USD mobilization and 350 USD/day per diem, lands near 92,000 USD. Estimators routinely price the man-hours but forget standby time for crane assembly delays, which can add 20 to 30 percent to the site bill.

Spare Parts Buffer prices the recommended spares package a buyer expects with the crane. A typical two-year commissioning spares list runs 2 to 4 percent of crane hardware value, so 40,000 to 90,000 USD on a mid-size unit. Price it at list less a stocking discount, and carry your own safety stock at 18 to 25 percent annual holding cost when you promise 24-hour dispatch. The error here is quoting spares at cost and eating the carrying charge, or omitting them entirely and losing the aftermarket margin, which often beats the equipment margin over the crane life.

Build the quote bottom-up from these seven lines, then add shop overhead at 12 to 20 percent of direct cost, engineering at 6 to 10 percent, and a contingency of 5 to 8 percent for rework and weather. Apply escalation on steel and copper for any project over 12 months, since a 10 percent plate move on a 1.2 million USD material line is 120,000 USD. Quotes go wrong through single-point estimates with no ranges, missing scrap and duty-cycle reality, and forgotten site standby. Quote each line with a low and high, and hold margin at the total rather than defending it line by line.

Published 2026-07-02.