Haul Truck Pre-Start Inspections Across Shift Changes

Picture an open-pit operation running a fleet of haul trucks, loaders, dozers and water carts around the clock. At the start of every shift, operators collect their units from the go-line and walk around them before starting work: tires and rims, lights, mirrors and cameras, steps and handrails, fluid leaks, the fire suppression system's indicator and the seat belt, then the horn, reversing alarm, brakes and steering once the engine is running.

In the United States this check is a regulatory requirement as well as good practice. For surface metal and nonmetal mines, MSHA's standard on safety defects requires self-propelled mobile equipment to be inspected by the operator before it is placed in operation on that shift. Defects affecting safety must be corrected in a timely manner. Equipment whose defects make continued operation hazardous must be taken out of service, and either placed in a designated area or tagged to prohibit further use. Safety defects that are not corrected immediately must be reported to and recorded by the mine operator, with the record kept until the defect is corrected.

The pre-start is therefore two things at once: a safety gate for this operator on this shift, and the first link in a chain that has to carry a defect to the workshop and keep it visible until it is fixed.

In many operations, the pre-start lives in a book in the cab or on a card handed in at the go-line. The check itself usually gets done. What happens next is less reliable. A defect is written down, the card goes into a box, and the box reaches the maintenance planner at the end of the shift or the next morning. Meanwhile the truck may have run a full shift with the defect, and the next operator may find the same problem and write it down again, with no way of knowing whether anyone has seen it.

The record of uncorrected defects, the one the standard asks the mine operator to keep, ends up spread across cab books, cards and the planner's spreadsheet. Answering a simple question, such as which units have open safety defects right now, means walking the go-line or making phone calls. Shift supervisors start each shift without a clear view of which units have been checked and which are carrying known problems.

Coverage in the pit adds another layer. A system that needs a live connection at the truck fails at exactly the places where the pre-start happens, and operators go back to the card.

In this scenario, each unit gets a durable QR tag inside the cab. Scanning it with a phone opens that unit's record in Vardian, with its pre-start form and any open work orders on it. The operator sees straight away if the unit is carrying a known defect, and the check is recorded against the right truck rather than a unit number written from memory.

The pre-start form follows the mine's existing card. Failed items are recorded with a photo and a note, and a failed item the mine classes as affecting safety becomes a corrective work order against the unit, straight from the inspection. The form works offline, so checks completed at the go-line or deep in the pit are stored on the phone and synced as soon as there is coverage.

Maintenance sees new defects as work orders against the right unit during the shift, not at the end of it. When the repair is done, the technician signs it off and it becomes part of the unit's history. Until then, the open defect stays visible on the unit's record to every operator who scans in, and supervisors can see at the start of each shift which units have completed their pre-starts and which are carrying open defects. Taking a unit out of service and tagging it remains the mine's own procedure; the record makes that status visible to everyone who needs it.

The rollout starts with one fleet type, usually the haul trucks, and the existing pre-start card converted item for item. Maintenance, safety and operations agree which items count as affecting safety, following the manufacturer's guidance and the mine's own procedures. That classification is the most important decision in the project, because it determines what stops a unit and what becomes priority work.

QR tags go inside each cab, where the operator sees them when climbing in, on a surface that survives dust, vibration and washdown. Training happens at the go-line during shift-start meetings, by doing a real pre-start on a real unit. For the first couple of weeks the cards stay in the cab as a fallback, while supervisors check that defects are reaching the workshop as work orders and that operators can see open defects when they scan in.

Maintenance agrees how pre-start work orders are triaged against the rest of the workload, and who decides when a unit returns to service. Once the haul fleet is running smoothly, loaders, dozers, water carts and light vehicles follow, each with a form that matches its own pre-start card.

The first thing operators notice is that writing a defect down now does something. It reaches the workshop during the shift, with a photo, and the next operator to scan in can see that it is already known and whether it has been fixed. The same cracked mirror stops being reported by every operator who drives the unit, each assuming nobody else has.

For maintenance, defects arrive as work against the right unit instead of as a stack of cards at shift change. Repeat defects on the same unit become visible as a pattern on its history, which is where reliability conversations about tires, brakes or hydraulics usually start.

For supervisors and the safety team, the question of which units have open safety defects right now has an answer on screen, and the record of uncorrected defects is kept against each unit until the defect is closed. If your pre-starts still live in cab books, a practical first step is to collect one week of cards and trace each recorded defect to its repair. Then see how mining teams use Vardian across inspections, maintenance and safety.