How to avoid double-counting equipment between neighboring pits

Most competitor mine sites run as a complex of two, three, sometimes five active cuts tied together by haul roads, a shared crusher, a shared workshop pad near the boundary. If you're building a fleet roster pit by pit off monthly imagery, that's exactly where unit counts get inflated. The excavator you counted at Pit A on Tuesday might be the same machine sitting at Pit B's ramp in next month's pass, not a second unit the operator bought.

This matters more for haul trucks and dozers than for shovels. A shovel usually stays matched to one face for weeks. A dozer gets sent wherever the ramp needs pushing that day, and a haul truck fleet at a multi-pit complex often works a shared route, loading at whichever pit is active and dumping at a central pad. Treat each pit as a sealed box and you'll count the same dozer twice, three times if it shows up in a third cut's frame too.

Where the double-count actually happens

A few specific failure points, in order of how often they bite:

Capture-time mismatch. When two neighboring pits in the same complex get imaged at different times of day, a truck that crossed the connecting road in the gap between those passes gets photographed at both. Same unit, two line items.

Boundary parking. Laydown yards, fuel points, and workshop pads often sit right on the line between two cuts. A parked grader near the boundary gets assigned to whichever pit the analyst happened to be looking at, and the next month it gets assigned to the other one, reading as churn that never happened.

Support fleet roaming. Dozers and graders move between faces far more than loading units do, because they're not tied to a shovel-truck match the way a production fleet is. A single dozer servicing three benches across two pits in one week is normal operations, not three dozers.

Ore-blending routes. Where a complex blends feed from two pits into one crusher, haul trucks cross the pit line as a matter of routine. Count trucks at the crusher approach and you'll double them against whatever you counted at the loading face.

How to keep the roster honest

Keeping the roster honest takes a counting discipline that treats the complex as the unit of analysis before it treats any single pit as one. Shooting imagery more often doesn't solve this on its own; the allocation logic has to change first.

Start with a complex-level pass: tally every haul truck, excavator, and dozer across the whole lease on the same monthly cadence, captured close enough in time that the same unit can't be caught twice crossing a haul road. Only after that total is settled should you allocate units down to individual pits, based on which working face or active bench a machine sits on at capture time, not which side of an arbitrary boundary line it happens to be parked.

Second, follow units pass to pass rather than recounting from zero each month. A haul truck has a paint scheme, a livery, sometimes a visible fleet number; tracking that signature across passes tells you when a unit actually relocated from Pit A to Pit C, versus when it's the same truck sitting in the same spot you're seeing for the second time because two pits share a frame edge.

Third, apply a simple tie-breaker for anything parked at a shared yard or boundary pad: assign it to the nearest active working face, and flag it rather than silently splitting it between two pit totals. A flagged unit you review once a quarter beats a phantom unit baked permanently into both rosters.

None of this is exotic. It's the same discipline a site-level ops team already applies when they reconcile hours against two adjacent pit schedules. The difference is you're doing it from monthly passes instead of a shift log, so the signature-tracking and capture-time steps carry more of the weight.

Get the allocation wrong and the error compounds. A single misassigned dozer in January becomes a trendline showing fleet growth at Pit B that never happened, and six months later that fabricated growth is in someone's market-share memo. Fleet sizing work doesn't tolerate that kind of ghost unit well.

If you'd rather not build this reconciliation logic in-house pit by pit, Mine Fleet OEM Share runs the monthly pass across the whole complex and holds the roster by manufacturer type over time, so shared equipment gets tracked as one unit moving, not three units appearing.

Worth a look if adjacent-pit fleet sharing is already skewing your competitor sizing numbers.