Underground Jumbo Development
Meters of advance per shift, per day and per month from the round you drill and
the jumbo that drills it, plus what a meter of heading costs you.
Underground development headings only: a twin-boom drill jumbo advancing a
drift, crosscut, ramp or decline by drill and blast. It is not a bench drilling tool, not a
continuous miner or roadheader model, not a ground-support design, and not a ventilation design.
It sizes the jumbo's share of the cycle only: mucking, charging, blasting, re-entry and
the rest of the ground support happen on other machines and are not in these numbers.
Step 1: The heading
Everything downstream is per meter of this profile.
Step 2: The round
Hole depth and pull set your advance. Nothing else in this tool moves it.
Step 3: The jumbo cycle
Setup, drilling and support. What one face costs the machine in hours.
Step 4: The shift
The gap between the cycle and the shift is where development schedules die.
Delays, as recorded on shift reports. These are the eight the source measured.
Step 5: Your costs
These are yours, not the handbook's. The source is explicit that development cost is too site-specific to publish as a rate.
Step 6: Benchmark it
A published all-in band to sanity-check what you just built up.
| Step | Value | Where it comes from |
|---|
The round, drawn
Where the shift goes
Rock density, if you do not know yours
| Rock | Bank density, t/m³ | lb/yd³ |
|---|---|---|
| Asbestos ore | 1.90 | 3,200 |
| Basalt | 2.95 | 5,000 |
| Bauxite | 1.90 | 3,200 |
| Chalk | 1.85 | 3,100 |
| Clay (dry) | 1.40 | 2,400 |
| Clay (light) | 1.65 | 2,800 |
| Clay (heavy) | 2.10 | 3,600 |
| Clay and gravel (dry) | 1.50 | 2,500 |
| Clay and gravel (wet) | 1.80 | 3,000 |
| Coal (anthracite) | 1.60 | 2,700 |
| Coal (bituminous) | 1.25 | 2,100 |
| Coal (lignite) | 1.00 | 1,700 |
| Copper ore (low-grade) | 2.55 | 4,300 |
| Copper ore (high-grade) | 3.20 | 5,400 |
| Earth (dry) | 1.65 | 2,800 |
| Earth (wet) | 2.00 | 3,400 |
| Granite | 2.41 | 4,000 |
| Gravel (dry) | 1.80 | 3,000 |
| Gravel (wet) | 2.10 | 3,600 |
| Gypsum | 2.80 | 4,700 |
| Limonite | 3.20 | 5,400 |
| Iron ore (40% Fe) | 2.65 | 4,500 |
| Iron ore (+40% Fe) | 2.95 | 5,000 |
| Iron ore (+60% Fe) | 3.85 | 6,500 |
| Iron ore (taconite) | 4.75 | 8,000 |
| Limestone (hard) | 2.60 | 4,400 |
| Limestone (soft) | 2.20 | 3,700 |
| Manganese ore | 3.10 | 5,200 |
| Phosphate rock | 2.00 | 3,400 |
| Sand (dry) | 1.70 | 2,900 |
| Sand (wet) | 2.00 | 3,400 |
| Sand and gravel (dry) | 1.95 | 3,300 |
| Sand and gravel (wet) | 2.25 | 3,800 |
| Sandstone (porous) | 2.50 | 4,200 |
| Sandstone (cemented) | 2.65 | 4,500 |
| Shales | 2.35 | 4,000 |
| Taconite | 3.68 | 6,210 |
SME Mining Engineering Handbook, Table 10.4-1, p. 933, after Atkinson 1992. Bank density is the rock as it sits in the ground, before it is blasted and swells, which is the same thing Table 12.2-1 calls rock density (wet) and the right number for this page. Pick the closest rock in Step 1 and it fills itself in. This table publishes every density twice, in tons per cubic meter and pounds per cubic yard, and the two agree across all 37 rows to within 1.7%, the gap being the book rounding the pounds column to the nearest hundred. The printed page also carries swell, fillability and digability columns; they describe loading the broken rock rather than drilling it, so they are deliberately not reproduced here.
What a jumbo drills, and how fast
| Drilling method | Diameter, mm | Typical depth, m | Rate, m/min | Rate, m/h | Accuracy, cm/m |
|---|---|---|---|---|---|
| Top hammer pneumatic jackleg | 25-50 | under 4 | 1.00 | 60 | 2-5 |
| Jumbo | 37-100 | 4-10 | 1.67-3.33 | 100-200 | 1-3 |
| Top hammer hydraulic jumbo | 37-125 | 4-20 | 0.50-2.00 | 30-120 | 2-3 |
SME Mining Engineering Handbook, Table 7.2-1, p. 439. The meters per minute column is converted from the printed meters per hour, because m/min is the unit Table 12.2-2 states penetration rate in. The printed footnote is what makes these numbers mean the same thing as the field in Step 3: "drilling rates are for actual drilling and do not include time for drill retraction, boom relocation, collaring, etc. Drilling rates decrease as rock mass strength increases and may increase or decrease depending on the number and orientation of joints/blocks." This page counts boom relocation and collaring separately, as boom setup per hole, so do not fold them into the rate as well or you pay for them twice. The surface crawler and down-the-hole rows on the printed page are for bench drilling and are left out. Note that the worked example drills a 3.05 m round, shorter than the 4 m these rows quote as typical.
The published example, table by table
| Physical development parameter | Measurement |
|---|---|
| Width, m | 5 |
| Height, m | 4.5 |
| Area, m² | 22.5 |
| Rock density (wet), t/m³ | 2.8 |
| Overbreak, % | 5 |
| Metric tons per meter (including overbreak), t/m | 66.2 |
| Drill factor, charged holes/m² | 2.2 |
| Number of charged holes | 50 |
| Number of 100-mm cut holes | 4 |
| Hole depth, m | 3.05 |
| Pull, % | 90 |
| Advance per round, m | 2.75 |
| Metric tons per round, t | 181.6 |
| 45-mm-diameter face holes, meters drilled, m | 151 |
| 100-mm-diameter cut holes, meters drilled, m | 12.2 |
| Total face meters drilled, m | 163.18 |
| Rock bolt length, m | 2.4 |
| Friction bolt holes per round | 5 |
| Resin bolt holes per round | 8 |
| Rock bolt meters drilled per round, m | 31.2 |
| Total small-diameter meters drilled per round, m | 182.2 |
| Face meters drilled per meter advance, m | 59.4 |
| Total meters drilled per meter advance, m | 70.8 |
SME Mining Engineering Handbook, Table 12.2-1, p. 1153. Loading this page reproduces every row of it. The printed overbreak is 5%, not the 5.6% our first transcription carried: 22.5 m² × 2.8 t/m³ × 1.05 gives the printed 66.2 t/m exactly, and 5.6% does not. Read off the printed page and corrected.
| Jumbo cycle component | Measurement |
|---|---|
| Tramming speed, k/h | 4 |
| Average distance between faces, km | 1 |
| Tramming time, min | 15 |
| Setup and markup time, min | 25 |
| Total setup time, min | 40 |
| Setup time (=engine hours) per cut, h | 0.7 |
| Drill meters per engine hour, m/h | 272 |
| Instantaneous penetration rate, 45-mm holes, m/min | 1.4 |
| Instantaneous penetration rate, 100-mm holes, m/min | 0.7 |
| Meters drilled, 45-mm holes, m | 182.2 |
| Meters drilled, 100-mm holes, m | 12.2 |
| Drilling time, 45-mm holes, min | 130.1 |
| Drilling time, 100-mm holes, min | 17.4 |
| Total drilling time, min | 147.6 |
| Total drilling time, h | 2.5 |
| Holes drilled (all types) | 67 |
| Boom setup time per hole drilled, s | 55 |
| Total boom set-up time, min | 61 |
| Total boom set-up time, h | 1 |
| Total set-up and drill time (2 booms), h | 3.5 |
| Average penetration rate per boom, m/min | 0.71 |
| Jumbo drilling time, h | 1.74 |
| Change centralizers, min | 10 |
| Rattle backs, min | 15 |
| Installation time per rock bolt, min | 1 |
| Total rock bolt installation time, min | 5 |
| Total ground-support time, min | 30 |
| Total ground-support time, h | 0.5 |
| Total jumbo time per face, h | 2.9 |
SME Mining Engineering Handbook, Table 12.2-2, p. 1154. Two rows here are printed values this tool does not reproduce and does not use: drill meters per engine hour, and average penetration rate per boom. Neither follows from the other cells on the page. The boom rate comes out at 0.93 m/min on every route through the table we could find, against a printed 0.71, so they are shown as published and left out of the chain rather than having a derivation invented for them.
| Development performance component | Measurement |
|---|---|
| Days per year | 365 |
| Days worked per week | 5 |
| Days worked per month | 21.7 |
| Shifts per day | 3 |
| Shift length, h | 8 |
| Shift change, h | 0.8 |
| No face available, h | 0.6 |
| No power, h | 0.5 |
| Meetings, h | 0.2 |
| Face not scraped, h | 0.2 |
| No ventilation, h | 0.2 |
| Pump/water problems, h | 0.1 |
| Maintenance/breakdown, h | 0.1 |
| Total delays, h | 2.7 |
| Balance of shift available, h | 5.3 |
| Faces drilled out | 1.82 |
| Face advance per shift, m | 5.01 |
| Face meters drilled per shift, m | 298 |
| Total meters drilled (including rock bolts) per shift | 354.7 |
| Meters drilled per month, m | 19,356 |
| Face advance per working day, m | 15 |
| Face advance per month, m | 325.6 |
SME Mining Engineering Handbook, Table 12.2-3, p. 1154. Measured at a mine where every jumbo had at least five faces available to it, so it was never waiting on a muck cycle.
Published all-in development costs
| Development item | Dimensions | $/m | $/ft |
|---|---|---|---|
| Drifts and crosscuts | 3.7 m w × 4.0 m h, bolted | 2,790–3,100 | 850–950 |
| Stope crosscuts | 3.4 m w × 4.0 m h, bolted | 2,550–2,900 | 780–880 |
| Stope attack ramps | 3.0 m w × 3.0 m h, bolted | 1,950–2,050 | 600–630 |
| Decline (contracted) | 4.9 m w × 5.5 m h, bolted, 152 mm shotcrete | 6,900 | 2,100 |
| Ventilation drift | 4 m w × 4.6 m h, bolted, 76 mm shotcrete | 3,850–4,050 | 1,175–1,230 |
| Ventilation raise | 2.4 m diameter, raisebored and lined | 6,250 | 1,900 |
SME Mining Engineering Handbook, Table 12.5-1, p. 1220, in 2009 US dollars at ±25%, for fairly fractured and weathered ground in central Nevada requiring regular bolting with split sets on 1.2 m centers. This table publishes every rate twice, in dollars per meter and dollars per foot, and the two agree to better than 1% on all six rows above, which is an independent check that a transcription cannot pass by accident. The seventh printed row, for pump stations and shops, is deliberately not carried here: it is quoted per unit of volume, and the book's own metric column converts it with the linear foot-to-meter factor instead of the cubic one, making it roughly eleven times too small.
What a heading actually achieves
| Situation | Advance | Source |
|---|---|---|
| Twin-boom jumbo, single heading, including stockpile bays | 47.5 m/week | typically 45 to 50 m/week |
| Twin-boom jumbo, single heading, main face only | 40 m/week | the rate that holds over a 2-year program |
| Cadia East, 6.0 × 5.5 m, long round, full ground support | 283 m/month | a record month, including stockpile bays (Willcox 2008) |
| Civil tunneling works | 400 m/month | exceeded, but not mine development |
All from the SME Mining Engineering Handbook, p. 1153. The single-heading numbers are the ones to hold this tool against. A model built on five available faces describes a jumbo that never waits; a decline being driven off one face is a different machine doing a different job.
Spending more time on spreadsheets than on the job?
We build the reporting and admin automation for mining contractors, so the numbers keep themselves.
Book a 20 min callWorked 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.
- 5.01 m
- 326 m
- $2093 / m
| Face area | 22.5 m² | width × height, Table 12.2-1 p. 1153 |
| Tons per meter of heading | 66.2 t / m | area × 2.80 t/m³ × 1.050 overbreak, the published example, Table 12.2-1 p. 1153 |
| Charged face holes | 49.5 | area × drill factor, carried unrounded as the source does |
| Advance per round | 2.75 m | hole depth × 90% pull, Table 12.2-1 p. 1153 |
| Tons per round | 181.6 t | tons per meter × advance |
| Face hole meters | 151.0 m | charged holes × hole depth |
| Cut hole meters | 12.2 m | 4 relief holes × hole depth |
| Rock bolt meters | 31.2 m | 13 bolt holes × bolt length |
| = small-diameter meters per round | 182.2 m | face holes + bolt holes, Table 12.2-1 p. 1153 |
| = total meters drilled per round | 194.4 m | all holes, Table 12.2-1 p. 1153 |
| Total meters drilled per meter of advance | 70.8 | the number that scales your consumables, Table 12.2-1 p. 1153 |
| Tramming time | 15.0 min | distance ÷ speed, Table 12.2-2 p. 1154 |
| + setup and markup | 25.0 min | your input |
| = setup per face | 0.67 h | Table 12.2-2 p. 1154 |
| Drilling, small-diameter holes | 130.1 min | small-diameter meters ÷ face rate |
| Drilling, cut holes | 17.4 min | cut meters ÷ cut rate |
| Holes of all types | 66.5 | charged + cut + bolt holes, each one a boom setup |
| + boom setup | 61.0 min | 66.5 holes × 55 s |
| = setup and drill time, all booms | 3.48 h | Table 12.2-2 p. 1154 |
| ÷ 2 booms = jumbo drilling time | 1.74 h | booms work the face together, Table 12.2-2 p. 1154 |
| Ground support by the jumbo | 0.50 h | centralizers + rattling + 5 bolts placed, Table 12.2-2 p. 1154 |
| = jumbo time per face | 2.90 h | setup + drilling + support, Table 12.2-2 p. 1154 |
| Shift length | 8.0 h | rostered |
| − recorded delays | 2.7 h | the eight categories in Step 4, Table 12.2-3 p. 1154 |
| = balance of shift available | 5.30 h | Table 12.2-3 p. 1154 |
| = faces drilled out per shift | 1.82 | balance ÷ jumbo time per face, Table 12.2-3 p. 1154 |
| = face advance per shift | 5.01 m | faces × advance per round, Table 12.2-3 p. 1154 |
| = face meters drilled per shift | 298 m | faces × face meters, Table 12.2-3 p. 1154 |
| = meters drilled per month | 19385 m | × 3 shifts × 21.7 days, Table 12.2-3 p. 1154 |
| = advance per working day | 15.03 m | × shifts per day, Table 12.2-3 p. 1154 |
| = advance per month, this jumbo | 326.1 m | total across every face it services, not one heading, Table 12.2-3 p. 1154 |
| Jumbos to hit 800 m/month | 3 | target ÷ advance per month, rounded up, p. 1153 |
| Jumbo and crew per meter | $798.51 / m | $500/h × 8.0 rostered h ÷ advance per shift |
| Drilling consumables per meter | $849.73 / m | 70.8 meters drilled per meter advanced × your rate |
| Rock bolts per meter | $213.11 / m | 13 bolts × $45 ÷ advance per round |
| Explosive per meter | $231.53 / m | tons per meter × your rate |
| = cost per meter, jumbo cycle only | $2093 / m | the four rows above |
| Published all-in benchmark | $2,790–3,100 / m | Drifts and crosscuts, 3.7 m w × 4.0 m h, bolted, 2009 USD ±25%, Table 12.5-1 p. 1220 |
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.