BIZOMAT MAKEOS · Mechanics
Machine Tipping Stability (Overturning, Safety Factor, Anchors)
Will this free-standing machine or cabinet tip over under a sideways acceleration or push, and if so, what anchor force holds it down?
Overturning check of a free-standing machine, rack or tank about its tipping edge by moments of forces: restoring moment of the weight about the edge (allowing for a floor slope), overturning moment from a horizontal acceleration at the centre of gravity (seismic, transport or braking) and from a horizontal force at its height, the safety factor against tipping, the acceleration and tilt angle that just tip it, and if the factor is short, the anchor tension per anchor to reach the required factor, against the anchor capacity.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Mass | kg | Mass of the machine with its contents. |
| Height of the centre of gravity | mm | Height of the centre of gravity above the floor. |
| Horizontal distance from the centre of gravity to the tipping edge | mm | Horizontal distance from the centre of gravity to the edge it would tip about. |
| Horizontal acceleration | g | Sideways acceleration as a share of gravity (seismic coefficient, transport or braking; your value from the code or duty). |
| Additional horizontal force | N | Extra horizontal push (wind, operator, hose pull). |
| Height of that force | mm | Height at which that push acts. |
| Floor slope towards the tipping edge | ° | Floor slope that leans the machine towards the tipping edge. |
| Safety factor against tipping required | Safety factor against tipping you require. | |
| Anchors on the far (uplift) side | Number of anchors on the side that lifts. | |
| Distance from the tipping edge to the anchors | mm | Distance from the tipping edge to the line of those anchors. |
| Anchor tension capacity | kN | Allowable tension per anchor (from the anchor maker for the floor). |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Mass
- What it is
- The mass of the machine with everything it carries in the condition checked: fluids, tooling, workpieces and attachments.
- Units and format
- Enter a number in kg: kilograms. The form accepts 0.000001 kg to 1000000 kg. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2000 kg as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Restoring moment and the gravity part of the overturning moment both scale with it; an added force does not.
What this means: Height of the centre of gravity
- What it is
- The height of the machine’s centre of gravity above the floor, from the maker’s data, CAD or a tilt test.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1200 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A higher centre of gravity increases the overturning moment and lowers the safety factor.
- Get it right
- Use the loaded condition; raised loads or heads lift the centre of gravity.
What this means: Horizontal distance from the centre of gravity…
- What it is
- The horizontal distance from the centre of gravity to the edge, foot or levelling pad the machine would tip about.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 400 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger distance raises the restoring moment and the safety factor.
- Get it right
- Measure to the tipping edge on the side the push acts towards, not to the machine centre.
What this means: Horizontal acceleration
- What it is
- The sideways acceleration applied to the machine, as a multiple of gravity: a seismic coefficient, braking or transport acceleration. Take it from the applicable code or your duty.
- Units and format
- Enter a number in g: grams. The form accepts 0 g to 5 g. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.3 g as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The overturning moment from inertia is proportional to it.
- Get it right
- Enter a fraction of g, not m/s²: 1 g = 9.80665 m/s².
What this means: Additional horizontal force
- What it is
- Any extra horizontal push on the machine besides its own inertia, such as wind, an operator pushing or a hose or cable pulling.
- Units and format
- Enter a number in N: newtons. The form accepts 0 N to 10000000 N. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0 N as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Enter 0 if there is none.
What this means: Height of that force
- What it is
- The height above the floor at which the extra horizontal push acts.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1500 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
What this means: Floor slope towards the tipping edge
- What it is
- The slope of the floor that leans the machine towards the tipping edge.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 0° to 45°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A steeper slope reduces the restoring moment.
- Get it right
- Enter the slope towards the tipping edge; a slope away from it is not modelled.
What this means: Safety factor against tipping required
- What it is
- The safety factor against tipping you require: the restoring moment divided by the overturning moment. Take it from the applicable standard or your design basis.
- Units and format
- Enter a plain number with no unit. The form accepts 1 to 5. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
What this means: Anchors on the far (uplift) side
- What it is
- The number of floor anchors along the side of the machine that would lift if it tipped.
- Units and format
- Enter a plain number with no unit. The form accepts 0 to 100. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Count only anchors on the uplift side; those at the tipping edge do not resist tipping.
What this means: Distance from the tipping edge to the anchors
- What it is
- The horizontal distance from the tipping edge to the line of anchors on the uplift side.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 800 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A longer lever arm reduces the tension each anchor needs.
What this means: Anchor tension capacity
- What it is
- The allowable tension per anchor in this floor, from the anchor maker’s data for the concrete and edge distances.
- Units and format
- Enter a number in kN: kilonewtons (1 kN = 1000 N). The form accepts 0 kN to 100000 kN. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 10 kN as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Use the allowable value for one anchor, not the total for all anchors.
Method and formulas
- Restoring moment M_r = W (b cos θ − h sin θ) on a slope θ.
- Overturning moment M_o = W a h + F_h h_F.
- Safety factor = M_r ÷ M_o; acceleration to tip = b ÷ h (level floor); tilt to tip = tan⁻¹(b ÷ h).
- Anchor tension per anchor = (factor × M_o − M_r) ÷ (anchors × L_a) when the factor is short.
- Example: 0.3 g gives a factor of 1.1111; 2 anchors each need 1.7162 kN to reach 1.5.
Limitations
- Rigid body tipping about one edge; sliding and dynamic rocking are separate checks.
- Anchor capacity must include edge distance and concrete strength.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a tall cabinet or machine for tipping
- Size floor anchors for a seismic or transport load
- Check a load on a forklift or trolley for tipping
Who it is for
- Design engineers
- Safety engineers
- Plant engineers
What you get
- Restoring and overturning moments
- Safety factor and the acceleration that tips it
- Anchor tension needed against capacity
Interpreting the result
- Lowering the centre of gravity or widening the base helps far more than adding weight.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 167–168, 221–227. Topic reference; no source tables or recommended settings are reproduced.
BIZOMAT tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Machine Tipping Stability (Overturning, Safety Factor, Anchors) calculator