Big Dog Mining

Shovel & Loader Productivity

Bank tons per hour and cost per ton. Pick the material you are digging and density, swell, bucket fill and digging class fill themselves from published tables. Every number shows its working and its source.

Step 1: What are you digging?

This one choice sets four values below. Override any of them if you have site data.

Material ?

Bank density auto ?

Weight of 1 m³ of material still in the ground.

Swell auto ?

1 m³ in the ground becomes this many m³ in the bucket.

Bucket fill factor auto ?

How full the bucket really gets. 1.00 = heaped rated capacity.

Digging class auto ?

Sets base cycle time. Harder digging = slower cycle.

Step 2: The machine and the bench

Defaults are a mid-size shovel on a well-set-up bench.

Rated bucket capacity ?

From the machine spec sheet. Heaped rating.

Swing angle ?

How far it slews from dig to dump. Spot the truck closer and this drops.

Bench height vs. ideal ?

Is the face tall enough to fill the bucket in one clean pass?

Job conditions ?

Floor, muck pile, room, weather.

Management ?

Operators, truck supply, delays, maintenance.

Owning & operating cost per hour (optional) ?$ / h

Depreciation, fuel, wear, operator. Gives you cost per ton.

bank tons / hour

cycle time, seconds

cost / bank ton

Step	Value	Where it comes from

Swing angle

What the hour actually buys

Material reference table: bank density, swell, fill factor and digging class

Material	Bank density (t/m³)	lb/yd³	Swell	Fill factor	Digging class
Asbestos ore	1.90	3,200	1.40	0.85	M: medium
Basalt	2.95	5,000	1.60	0.80	H: hard
Bauxite	1.90	3,200	1.35	0.90	M: medium
Chalk	1.85	3,100	1.30	0.90	M: medium
Clay (dry)	1.40	2,400	1.25	0.85	M: medium
Clay (light)	1.65	2,800	1.30	0.85	M: medium
Clay (heavy)	2.10	3,600	1.35	0.80	M-H: medium-hard
Clay and gravel (dry)	1.50	2,500	1.30	0.85	M: medium
Clay and gravel (wet)	1.80	3,000	1.35	0.80	M-H: medium-hard
Coal (anthracite)	1.60	2,700	1.35	0.90	M: medium
Coal (bituminous)	1.25	2,100	1.35	0.90	M: medium
Coal (lignite)	1.00	1,700	1.30	0.90	M: medium
Copper ore (low-grade)	2.55	4,300	1.50	0.85	M-H: medium-hard
Copper ore (high-grade)	3.20	5,400	1.60	0.80	H: hard
Earth (dry)	1.65	2,800	1.30	0.95	E: easy
Earth (wet)	2.00	3,400	1.30	0.90	M: medium
Granite	2.41	4,000	1.55	0.80	H: hard
Gravel (dry)	1.80	3,000	1.25	1.00	E: easy
Gravel (wet)	2.10	3,600	1.25	1.00	E: easy
Gypsum	2.80	4,700	1.50	0.85	M-H: medium-hard
Limonite	3.20	5,400	1.40	0.85	M: medium
Iron ore (40% Fe)	2.65	4,500	1.40	0.80	M-H: medium-hard
Iron ore (+40% Fe)	2.95	5,000	1.45	0.80	M-H: medium-hard
Iron ore (+60% Fe)	3.85	6,500	1.55	0.75	H: hard
Iron ore (taconite)	4.75	8,000	1.65	0.75	H: hard
Limestone (hard)	2.60	4,400	1.60	0.80	M-H: medium-hard
Limestone (soft)	2.20	3,700	1.50	0.85	M-H: medium-hard
Manganese ore	3.10	5,200	1.45	0.85	M-H: medium-hard
Phosphate rock	2.00	3,400	1.50	0.85	M-H: medium-hard
Sand (dry)	1.70	2,900	1.15	1.00	E: easy
Sand (wet)	2.00	3,400	1.15	1.00	E: easy
Sand and gravel (dry)	1.95	3,300	1.15	1.00	E: easy
Sand and gravel (wet)	2.25	3,800	1.15	1.00	E: easy
Sandstone (porous)	2.50	4,200	1.60	0.80	M: medium
Sandstone (cemented)	2.65	4,500	1.60	0.80	M-H: medium-hard
Shales	2.35	4,000	1.45	0.80	M-H: medium-hard
Taconite	3.68	6,210	1.70	0.80	H: hard

Atkinson 1992, via the SME Mining Engineering Handbook, Table 10.4-1 (p. 933). All 37 materials from the printed table are listed here, verified against the page. If your material is not in the list, pick the closest match by hardness and density, or enter your own values; each field can be overridden.

One limit worth knowing. The cycle-time table covers buckets from 3 to 35 m³ (4 to 45 yd³). Inside that range the calculator interpolates between published sizes. Outside it, the answer is extrapolated beyond what the source measured. It will still give you a number, but treat it as an indication rather than an estimate.

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Worked example

Worked with the values this page loads with, so the method can be checked against the cited source without entering anything. Change any input above and the calculator recomputes; the numbers below stay as a fixed reference case.

1187
33.0

Base cycle time (M-H: medium-hard digging, 11.5 m³ bucket)	33.0 s	Shovel cycle times, Ch. 12
× swing angle correction	× 1.00	Bench and swing angle corrections
× bench height correction	× 1.00	Bench and swing angle corrections
= cycle time	33.0 s
Bucket, rated	11.50 m³	your input
× fill factor	× 0.80	Table 10.4-1 fillability
= loose volume carried	9.20 m³
÷ swell (1.45 loose per bank)	× 0.690	Table 10.4-1 swell factor
= bank volume per pass	6.34 m³
× passes per hour (3600 ÷ cycle)	× 109.1
× operating efficiency	× 0.73	Job Good / management Good
× bank density	× 2.35 t/m³	Table 10.4-1
= bank tons per hour	1187 t/h

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Estimating aid only. This is not an engineering design and not a substitute for the judgment of a competent or qualified person. Verify every result against the cited source and your own site conditions. Full terms and disclaimer.