Aerial Ladder Reach
Horizontal and vertical reach from angle and extension.
Example
You enter
- Angle (degrees) 70
- Ladder extension (ft) 100
You get
- Horizontal reach 34.2 ft
- Vertical reach 94.0 ft
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
Formula or tableHorizontal reach = ladder_length × cos(angle); vertical reach = ladder_length × sin(angle), measured from the turntable pivot; a manufacturer's rated vertical reach adds the pivot height above grade (Spartan's 75 ft rear mount prints 75 ft vertical where 75 x sin 72 is 71.3), so add it for the height above the street.
Source and editionNFPA 1901 (Standard for Automotive Fire Apparatus) by name; manufacturer aerial-device technical data sheets (Pierce, E-One, Sutphen) by name.
Free accessNFPA 1901 read-only at nfpa.org/freeaccess; manufacturer specs free on each manufacturer site.
What governsEstimate. AHJ and licensed fire protection engineer govern.
API field namesangle_deg, extension_ft, horizontal_reach_ft, vertical_reach_ft