Transfer Station Throughput and Trailer Loadout
Sizes unloading positions from the peak hour rather than the daily average, the trailer fleet from the round trip.
Example
You enter
- Daily tonnage (tons) 800
- Operating hours 10
- Share of the day in the peak hour (%) 15
- Collection vehicle payload (tons) 8
- Vehicle time on the floor (min) 6
- Transfer trailer payload (tons) 22
- Trailer round trip (hours) 3
- Loose density of tipped waste (lb/cy) 400
- Workable pile depth (ft) 8
- Manoeuvring factor 3
- Loadout delay to absorb (hours) 2
You get
- Peak hour 120 tons, 15.0 vehicles per hour
- Peak arrivals per hour 15
- Unloading positions required 2
- Average positions 1
- Trailer loads per day 37 loads, 3.33 per trailer
- Loads per trailer 3.33333
- Trailer fleet 12 trailers
- Waste on the floor during the delay 160 tons (800 cy)
- Surge (cy) 800
- Tipping floor the surge needs 8100
No published worked example is on file for this calculation. It is checked against a hand-worked derivation of its method and an independent reference test.
Details, formula, and sources
ScopeSizes unloading positions from the peak hour rather than the daily average, the trailer fleet from the round trip, and the tipping floor from how long the trailers can be late. The worked station needs 2 positions against 1 on the average, 12 trailers, and 8,100 sq ft to absorb a 2 hour delay.
Formula or tablepeak hour tonnage = daily tonnage x the peak share; unloading positions = peak arrivals x floor time; trailer loads = tonnage / payload rounded up; fleet = loads / (operating hours / round trip); surge floor = delayed tonnage / loose density / pile depth x a manoeuvring factor.
Source and editionQueueing and volumetric arithmetic. The facility's own scale records, its permit's throughput limit, and the traffic study govern.
Free accessPublic arithmetic; the arrival profile is the facility's own data.
What governsEstimate. AHJ and licensed professional govern.
API field namesdaily_tons, operating_hours, peak_hour_share_pct, collection_payload_tons, floor_time_min, trailer_payload_tons, trailer_round_trip_hr, loose_density_lb_per_cy, pile_depth_ft, manoeuvring_factor, loadout_delay_hr, peak_hour_tons, peak_arrivals_per_hour, unloading_positions, average_positions, trailer_loads_per_day, loads_per_trailer, trailer_fleet, surge_tons, surge_cy, surge_floor_sqft
- Peak share entered; sizing the inbound side on the daily average queues trucks onto the street when routes come in togetherfacility scale records
- Manoeuvring factor entered multiplier on the bare pile footprint for equipment and trafficfacility layout