Underground Haulage Distance Calculator
Travel time on each leg is distance divided by speed.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the one-way haul distance in metres (portal or loading point to the tip/dump).
- Enter the loaded tram speed in km/h; add an empty return speed if it differs (it defaults to the loaded speed).
- Optionally add fixed loading/spot and dumping/manoeuvre times to get the full cycle time and trips per hour for one unit.
How it works
Travel time on each leg is distance divided by speed. The calculator converts the one-way distance from metres to kilometres, then computes one-way loaded time = (distance / loaded speed) x 60 minutes and one-way empty time = (distance / empty speed) x 60 minutes. The full haulage cycle adds any fixed loading and dumping times: cycle = loaded travel + empty travel + load + dump.
Trips per hour for a single unit is 60 divided by the cycle time in minutes, and the round-trip distance is simply twice the one-way distance. The model assumes a constant tramming speed on each leg with no acceleration, gradient resistance, ventilation restrictions, queueing or operational delays — real underground cycles are slower once ramp grades, passing bays, traffic-management stops and availability are included.
Worked example
1,200 m decline haul at 12 km/h loaded, 18 km/h empty. For a 1,200 m one-way haul with a loaded tram speed of 12 km/h, an empty return speed of 18 km/h, 2 min loading and 1.5 min dumping: one-way loaded time = 1.2 km / 12 km/h x 60 = 6 min, one-way empty time = 1.2 km / 18 km/h x 60 = 4 min. Full cycle = 6 + 4 + 2 + 1.5 = 13.5 min, giving 4.44 trips per hour for a single unit over a 2,400 m round trip.
Common mistakes
- Mixing units — entering the distance in metres but treating the speed as m/s. Speeds here are km/h and distance is metres; the tool converts internally, so keep to those units.
- Using the same speed for the loaded and empty legs when the empty return is faster. Enter a separate empty speed, or leave it blank to reuse the loaded speed.
- Reading the cycle time as fleet productivity. This is one unit's cycle with no allowance for availability, utilisation, queueing or bunching — apply those separately before sizing a fleet.
Frequently asked questions
Does this account for ramp grade slowing the truck down?
No. It uses the constant tram speed you enter for each leg. Grade, acceleration and deceleration reduce real speeds, so enter effective average speeds for the loaded (usually uphill/slower) and empty legs rather than flat-ground rated speeds.
Can I use it for an LHD or loader tramming ore rather than a truck?
Yes. The same distance-over-speed cycle applies to any tramming unit — LHD, loader or truck. Enter the tram distance, the loaded and empty tram speeds, and the bucket load/dump times to get the cycle and trips per hour.
Why are trips per hour lower than expected on a real site?
Because this is an ideal constant-speed cycle. Real underground haulage loses time to queueing at loading points, passing-bay waits, traffic management, tramming restrictions in ventilation-limited headings, and equipment availability. Apply an availability/utilisation factor to the trips per hour for a realistic production figure.
Related tools
- Truck Cycle Time Calculator
- Fleet Productivity Calculator
- Confined Space Volume Calculator
- Decline Grade & Distance Calculator
- LHD Bucket Fill Factor Calculator
- Development Advance Rate Calculator
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