| Chapter 8 - Cost Estimating |
| Number |
Topic |
Rule of Thumb |
| 8.01 |
Cost of Estimating |
A detailed estimate for routine, repetitive work (i.e. a long drive on a mine level) may cost as little as 0.5% of the project cost. On the other hand, it may cost up to 5% to adequately estimate projects involving specialized work, such as underground construction and equipment installation. Various Sources |
| 8.02 |
Cost of Feasibility Study |
The cost of a detailed feasibility study will be in a range from 0.5% to 1.5% of the total estimated project cost. Source: Frohling and Lewis |
| 8.03 |
Cost of Feasibility Study |
The cost of a detailed or “bankable” feasibility study is typically in the range of 2% to 5% of the project, if the costs of additional (in-fill) drilling, assaying, metallurgical testing, geotechnical investigations, etc. are added to the direct and indirect costs of the study itself. Source: R. S. Frew |
| 8.04 |
Budget Estimates |
An allowance (such as 15%) should be specifically determined and added to the contractor’s formal bid price for a mining project to account for contract clauses relating to unavoidable extra work, delays, ground conditions, over-break, grouting, de-watering, claims, and other unforeseen items. Source: Jack de la Vergne |
| 8.05 |
Engineering, Procurement, and Construction Management |
The Engineering, Procurement, and Construction Management (EPCM) cost will be approximately 17% for surface and underground construction and 5% for underground development. Source: Jack de la Vergne |
| 8.06 |
Overbreak |
The amount of over-break to be estimated against rock for a concrete pour will average approximately 1 foot in every applicable direction, more at brows, lips, and in bad ground. Source: Jack de la Vergne |
| 8.07 |
Overbreak |
On average, for each 1 cubic yard of concrete measured from the neat lines on drawings, there will be 2 cubic yards required underground, due to overbreak and waste. Source: Jack de la Vergne |
| 8.08 |
Haulage |
The economical tramming distance for a 5 cubic yard capacity LHD is 500 feet and will produce 500 tons per shift, for an 8-yard LHD, it is 800 feet and 800 tons per shift. Source: Sandy Watson |
| 8.09 |
Haulage |
Haulage costs for open pit are at least 40% of the total mining costs; therefore, proximity of the waste dumps to the rim of the pit is of great importance. Source: Frank Kaeschager |
| 8.10 |
Miscellaneous |
Developing countries have labor costs per ton mined equal to approximately 80% of industrialized nations, considering pay scales, mechanization, education, and skill levels. Source: Kirk Rodgers |
| 8.11 |
Miscellaneous |
The installed cost of a long conveyorway is approximately equal to the cost of driving the drift or decline in which it is to be placed. Source: Jack de la Vergne |
| 8.12 |
Miscellaneous |
The total cost of insurance on a contract-mining job will be approximately 2% of the contract value (including labor). Source: Darren Small |
| 8.13 |
Miscellaneous |
In a trackless mine operating around the clock, there should be 0.8 journeyman mechanic or electrician on the payroll for each major unit of mobile equipment in the underground fleet. Source: John Gilbert |
| 8.14 |
Miscellaneous |
On average, for each cubic yard of concrete measured from the neat lines on drawings, approximately 110 Lbs. of reinforcing steel and 12 square feet of forms will be required. Source: Jack de la Vergne |
| 8.15 |
Miscellaneous |
To estimate shotcrete (dry type) through the machine, add 25% to the neat line take-off to account for surface irregularity (roughness) and overbreak. Then add rebound at 17-20% from the back and 10% from the wall. Source: Baz-Dresch and Sherril |
| 8.16 |
Miscellaneous |
The overall advance rate of a trackless heading may be increased by 30% and the unit cost decreased by 15% when two headings become available. Source: Bruce Lang |
| 8.17 |
Miscellaneous |
The cost to slash a trackless heading wider while it is being advanced is 80% of the cost of the heading itself, on a volumetric basis. Source: Bruce Lang |