Crane Pad Solutions UK
Crane Pad Solutions UK
Outrigger Pad Size Calculator

Enter your maximum outrigger load and select your ground type. We will calculate the minimum pad area required and recommend the right pad from our range.

Step 1 of 2
Maximum Load Per Outrigger

Use the maximum outrigger load from your crane's load chart at the intended radius. If unsure, divide gross vehicle weight by the number of outriggers.

Tonnes
Step 2 of 2
Ground Type

Select the ground type at your outrigger positions. Use the weakest type if conditions vary across the site.

Tarmac or Concrete
Hard standing, roads, car parks — 200 kN/m²
Compacted Gravel
Well compacted hardcore or gravel — 150 kN/m²
Firm Natural Ground
Firm clay or dense natural soil — 100 kN/m²
Grass or Topsoil
Lawn, field, soft topsoil — 75 kN/m²
Soft or Variable Ground
Made ground, fill, suspect bearing — 50 kN/m²
Not Sure
Conservative 50 kN/m² default used

Load Distribution Guidance

Crane Outrigger Pad Load Distribution Guide

Practical guidance on outrigger pad sizing, ground pressure and spread area for crane operators and plant hire contractors across the UK.

This page does not replace a lift plan, crane manufacturer instructions or assessment by a qualified Appointed Person. For project-specific advice, call 07752 806706.

Why Load Distribution Matters

Outrigger loads are high and concentrated. When ground bearing capacity is exceeded the result is settlement, rotation or instability — all of which create serious risk during lifting operations.

An outrigger pad increases contact area between the crane outrigger foot and the ground, reducing ground pressure and improving stability. The larger the pad, the lower the pressure per square metre.

Ground failure is most commonly caused by insufficient spread area, soft or variable ground conditions, inadequate ground assessment before lifting, or incorrect pad positioning.

What You Need Before Selecting a Pad

To recommend the right pad you need three things:

1. Maximum outrigger reaction force — from the crane duty chart or outrigger load table, expressed in kN or tonnes.

2. Ground bearing capacity — from a ground assessment or a conservative site assumption if no formal assessment has been carried out.

3. Any existing spread — timber packers, steel grillage, crane mats or other materials already under the outrigger foot.

If you do not have all three, call us and we will work from conservative assumptions.

Ground Pressure — The Basic Principle

Ground Pressure = Load ÷ Area

Increase the pad area and ground pressure drops. This is why larger pads and modular outrigger systems are used on soft ground, made ground, wet sites, sites with buried services, or any application with tight ground pressure tolerances.

Warning Signs You Need More Spread Area

If you observe any of the following, increase pad size or add modular sections before continuing:

  • Outrigger foot settling or pumping after load is applied
  • Cracking or deformation of the ground surface
  • Pads rocking or not fully supported under load
  • Soft spots, recently backfilled trenches or disturbed ground
  • Saturated ground, standing water, peat or loose stone
  • Close proximity to edges, culverts, drainage chambers or voids

Pad Positioning — Non-Negotiables

  • Pads must sit flat and fully supported with no bridging underneath
  • Remove loose material and level the ground surface where possible
  • Keep pads clear of excavation edges and any area where ground can shear
  • Do not stack unstable materials beneath an outrigger load
  • Reassess ground condition after initial load application

Which Outrigger Pad Type to Use

Round crane pads are best suited to general outrigger applications. They provide consistent load spread and are straightforward to handle and position.

Square crane pads maximise footprint for a given pad size. Useful where orientation or edge alignment affects the available spread area.

Modular outrigger pad systems (1500mm and 1800mm sections) provide a scalable footprint. Sections combine to increase spread area and adapt to different outrigger configurations and ground conditions. Suitable for higher loads, weaker ground or where a repeatable system is needed across a fleet.

Need Help Selecting the Right Pad?

Provide the following and we will recommend a suitable pad size or modular configuration:

  • Crane model and lift configuration
  • Maximum outrigger reaction load or duty chart reference
  • Site location and ground type

Call 07752 806706 or email sales@cranepadsolutionsuk.co.uk

Important Safety Notice

All load guidance on this page is indicative only. Ground conditions vary and can change rapidly with weather and site activity. All pad selection and ground assessment must be verified by a competent person on site.