A mine workshop is a crane building with a dirty floor
A mine maintenance workshop services haul trucks, loaders, drills and support equipment. Machines arrive dirty and leave working, and the component that has to be lifted out sets the height and the crane.
The largest component decides the building
Every workshop has one lift that defines it: an engine, a differential, a dump body, a boom. That mass and the height it must clear determine the crane capacity, the rail level and the door size.
Designing from a general description of "truck workshop" produces a building that cannot do the one lift the mine actually needs. The component list is available at the start of every mine project.
Clear span is worth more here than anywhere
Internal columns in a workshop obstruct machine movement, block door positions and create blind spots for the crane. For a workshop handling vehicles with a large turning radius, the columns are a permanent operational penalty.
That is the argument for a longer span, and it is usually won on the basis of the vehicle envelope rather than the structure.
The floor takes abrasion, impact and oil
Mine equipment brings in rock, slurry and oil. The floor is abraded by tracks and tyres, impacted by dropped components, and contaminated by fuel and hydraulic fluid.
A slab designed only for load will spall at the surface within a few years. What is needed is a surface layer designed for abrasion, joints that survive impact, and falls to a separator so that oil does not reach the drainage system untreated.
Washdown is part of the process
Machines are washed before and after maintenance. That wash water carries solids and oil, and it has to go somewhere designed rather than to the lowest point of the yard.
A wash bay with a settlement pit and a separator is a small civil structure that saves a large environmental problem.
The store and the workshop are different buildings
Parts, lubricants, tyres and chemicals are stored next to the workshop because that is where they are used. Each of those is a different hazard: lubricants and chemicals are a fire load and a pollution risk, tyres are a very large fire load, and parts are heavy point loads.
Separating the flammable and chemical stores from the workshop with a fire wall is the same argument as in any industrial plant, and at a mine the quantities are larger than most.
What I want before drawings
- The equipment serviced and the largest component to be lifted.
- The crane capacity, span and rail level, and whether it is fixed or mobile.
- The clear span needed for vehicle movement.
- The floor loading, abrasion and drainage requirements.
- The store volumes and which stores need separation.
- The wind speed for the site in km/h from the applicable local code, not a round number.
Mine workshops are expensive buildings that are worth getting right, because a mine that cannot service its fleet loses production every day the workshop does not work.
Written by Johnny Joe, who advises owners and project managers in Africa and South America on steel buildings. If this decision is live on a project, send the layout and the constraint that worries you and I will tell you what it changes.
Related: a workshop laid out around vehicles · where the crane rail goes · a crane building with a heavy floor · separating a store
