ENGINEERING TOOL
OUTRIGGER LOAD CALCULATOR
Determine the minimum bog mat size required for your crane setup to ensure safe ground bearing pressure.
BOGMATS
AUSTRALIA
How to Use the Crane Outrigger Load Calculator
The Crane Outrigger Load Calculator provides a practical starting point for estimating the ground support requirements of a crane setup. Enter the relevant outrigger load and allowable ground bearing pressure to help determine an appropriate bog mats size for the conditions being considered. Where available, use the manufacturer’s crane load information and site-specific ground data rather than relying on default estimates. The calculator is intended to help with preliminary planning and comparison of ground support options before a lift is undertaken.
Understanding Ground Bearing Pressure
Ground bearing pressure is the pressure transferred from a crane outrigger to the supporting ground. The allowable pressure depends on the ground conditions and should be established using appropriate site information or engineering advice. A bog mats increases the contact area between the outrigger and the ground, helping distribute the load over a larger area. For more information, see our guide to Ground Bearing Pressure.
Selecting the Correct Bog mat
Selecting the correct bog mats depends on the outrigger load, allowable ground bearing pressure, required support area and the conditions of the lift. Bog mats are available in different materials and sizes for different applications. Our Steel Bog mats provide engineered support for demanding crane and heavy-lifting applications, while Poly Cribbing Blocks can provide a lightweight and durable ground-support option. The calculator can assist with preliminary sizing, but the final selection should consider the complete site and lifting conditions.
Important Engineering Disclaimer
This calculator provides preliminary guidance only and is intended to assist with initial planning and ground-support discussions. Results are based on the information entered and should not be treated as a final engineering design or certification. Actual ground conditions, crane configuration, outrigger loads, load distribution, mat construction and site conditions must be assessed by a suitably qualified engineer. The calculator does not replace a qualified engineering assessment or the crane manufacturer’s load information. For project-specific assistance, please Contact us / Request a Quote.
Frequently Asked Questions
What information do I need to use the calculator?
You will generally need the maximum outrigger load and the allowable ground bearing pressure for the site. Where available, use the crane manufacturer’s load information and site-specific ground data. If the ground bearing pressure is unknown, obtain appropriate engineering advice rather than relying solely on an estimated value.
What is allowable ground bearing pressure?
Allowable ground bearing pressure is the maximum pressure that the supporting ground can safely withstand for the conditions being considered. It varies according to factors such as soil type, ground condition, moisture, compaction and other site conditions. A qualified engineer or geotechnical professional should determine the appropriate value where required.
Does the calculator select a specific bog mats?
The calculator can provide preliminary guidance on the support area or bog mats size based on the information entered. It should not be treated as a final product selection. The appropriate bog mats must also be assessed against its construction, dimensions, load capacity, configuration and the actual conditions of the lift.
Can it be used for offset outrigger loads?
Offset outrigger loading can change how forces are distributed through the supporting bog mats and ground. The calculator may assist with preliminary calculations, but offset loading should be assessed using the actual crane configuration and loading arrangement. A qualified engineer should review non-standard or complex lifting conditions.
Do the results replace an engineering assessment?
No. The calculator provides preliminary guidance only and does not replace a qualified engineering assessment. The results should be considered alongside crane manufacturer information, site conditions and project-specific engineering requirements before equipment is selected or a lift is undertaken.