Felling Notch and Hinge Geometry
Recommended open-face notch depth, hinge thickness, and hinge width from the felling-cut diameter.
Example
You enter
- Diameter at the felling cut (in) 20
- Notch depth (% of diameter) 22
- Open-face angle target (deg) 70
You get
- Notch depth 4.4 in
- Hinge thickness 2 in
- Hinge width 16 in
Checked against published worked examples from: ANSI Z133-2017 open-face felling.
Details, formula, and sources
ScopeRecommended open-face notch depth, hinge thickness, and hinge width from the felling-cut diameter, with the ANSI Z133 cautions. A qualified faller governs.
Formula or tablenotch_depth = dia x notch_pct/100 (default 22%); hinge_thick = dia x 0.10; hinge_width = dia x 0.80; open-face angle 70 deg or more.
Source and editionANSI Z133-2017 (Arboricultural Operations - Safety Requirements) open-face felling practice by name; standard faller guidance.
Free accessANSI Z133-2017 is a published consensus standard. The open-face geometry is standard faller practice.
What governsMath aid for personal verification. Stop work and consult the qualified person on site if any number does not match the field condition.
API field namescut_dia_in, notch_pct, open_face, notch_depth_in, hinge_thick_in, hinge_width_in
- Open-face defaults notch 20-25% of dia (default 22), hinge ~10%, width ~80%, open face 70 deg+ANSI Z133-2017 / faller practice