HOSCH — Carryback & Savings Calculator

Step 1 · Your conveyor

Please enter all costs in Australian dollars. Every figure this tool returns is in AUD.

Belt width

Measured edge to edge

Loading width (mm)

Width of material on the belt

Belt speed

From the drive nameplate

Material

Operating hours / year

Hours per day × days per year

Hours to shovel 1 tonne

Benchmark 1–4 h

Labour rate (AUD/hour)

Benchmark $25–$256 AUD

Material value (AUD/tonne)

Set by material, override as needed

Your clean-up cost works out at $268 AUD per tonne. That is 2 h × $100/h + $68/t — the same three-part calculation HOSCH use on every carryback test report. Across our benchmark sites it ranges from $48 to around $900 a tonne, so these three numbers matter more than anything else on this page.

Step 2 · Your scraper

Main scraper

Return side / under belt — the secondary clean · order TBC

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Also suitable

Pre-scraper

Head pulley — the primary clean

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Also suitable

Two jobs, two positions. The pre-scraper takes the bulk off at the head pulley; the main scraper cleans the residual layer on the return side. They work together rather than as alternatives. Options marked wet only are not normally specified as pre-scrapers and are shown last — B9 and B9S suit wet material and B9S is a diagonal plough, so treat both as a last resort.

Step 3 · One year of carryback, side by side

Simulated: 0 days of 365

Conventional scraper HOSCH scraper Belt runs left to right, discharges over the head pulley, returns underneath. Particle fall rate is proportional to real carryback — the picture is the data.

Step 4 · What it's worth, every year

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Tonnes of carryback saved

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Clean-up cost avoided (AUD)

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Cleaner belt

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Rail wagons of material recovered a year (20 t each)

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Carryback level, against the CEMA 576 scale

Where these numbers come from

The equation

Cb (kg/h) = Lcb (kg/m²) × loading width (m) × belt speed (m/s) × 3600

tonnes/year = Cb × operating hours ÷ 1000

$/tonne = (hours to shovel a tonne × labour rate) + material value

From HOSCH Carryback Economy slides 5–6, CEMA No. 576 (2014), and the 40 HOSCH carryback measurement reports. Verified against every report where the trial period and weighed grams are recorded — it reproduces the printed kg/h on all of them.

Loading width, not belt width. Material only sits on part of the belt, and every report records the two separately — one Pilbara iron ore conveyor is a 900 mm belt carrying material across just 450 mm of it. Across the 18 reports the loading width averages 77% of belt width.

Carryback levels used: 12.73 g/m² for a conventional scraper and 1.59 g/m² for HOSCH, recomputed from each report's own loading width and trial period. That is a 87.5% reduction. HOSCH publish 83%, which is the average of each site's own percentage rather than a comparison of the averages — both are correct, they answer slightly different questions.

The 18 benchmark sites

Site / conveyor	Material	Belt (mm)	Speed (m/s)	Loading (mm)	Conventional (t/yr)	HOSCH (t/yr)	Saved (per yr)

Across these 18 paired tests: 794 t of carryback saved a year, and a median saving of $116,307. The mean is $265,423, but one West Pilbara magnetite operation sits so far above the rest that the median is the fairer figure to quote.

Figures are as recorded at the time of each test, between 2001 and 2018, and are not adjusted for inflation. Tests outside Australia may have been recorded in local currency, so the site figures are shown as currency-neutral. Your own result above is in AUD.

† The nickel site's material value of $9,000 a tonne appears to be a refined metal price rather than the value of the conveyed ore, and is being checked against the original report. Its carryback measurements are sound and are included in the tonnage average; its dollar figure is excluded from the savings averages above until the value is confirmed.

The CEMA carryback scale

Level	Carryback	Meaning
Level I	over 250 g/m²	Poorly cleaned
Level II	100 – 250 g/m²	Basic cleaning
Level III	10 – 100 g/m²	Good cleaning
Level IV	2 – 10 g/m²	CEMA's highest standard

The 13-site average puts conventional scrapers in Level III and HOSCH below Level IV — better than the highest grade CEMA defines.

All figures in Australian dollars. Estimates based on HOSCH field measurements. Actual results vary with material, moisture, belt condition and duty. Figures should be confirmed with your HOSCH dealer before being used commercially.