Drafting Maximum Lift (Altitude-Corrected)
Maximum drafting lift from a static source.
Example
You enter
- Site elevation (ft above sea level) 3000
- Pump condition factor (0-1, default 0.667) 0.667
You get
- Theoretical lift 30.9 ft
- Attainable lift 20.61
Details, formula, and sources
theoretical = 33.9 - elevation/1000; attainable = factor x theoretical - suction losses (factor about 2/3). A real pump cannot pull a perfect vacuum, and every 1,000 ft of altitude shaves a foot -- lift is set by atmosphere pushing water up the suction, not the pump. A planning aid, not incident command.
theoretical_lift = 33.9 - site_elevation / 1000; attainable_lift = pump_factor x theoretical_lift - suction_losses (pump_factor about 2/3).
IFSTA / NWCG firefighter math altitude-corrected drafting maximum lift, by name.
The drafting-lift relations are public fire-service / wildland training material; incident command governs the actual setup.
Estimate. AHJ and licensed professional govern.
Field names used by the API: site_elevation_ft, pump_factor, theoretical_lift_ft, attainable_lift_ft
- Practical ceiling about two-thirds of theoretical (about 22.5 ft at sea level); a perfect vacuum is unattainableIFSTA / NWCG
- Altitude correction theoretical lift falls about 1 ft per 1,000 ft of elevationatmospheric pressure vs altitude